Updated: 17 June 2020
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| Tropical Cyclones
[Index] | Tropical Cyclone NATHAN : JTWC Advisories |
| Season 1997-1998 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
| ---> Tropical Cyclone NATHAN Track Map and Data |
WTPS32 PGTW 980321 03:00z
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 001
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
210000Z3 --- 11.2S4 143.4E2
MOVEMENT PAST SIX HOURS - 245 DEGREES AT 02 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
REPEAT POSIT: 11.2S4 143.4E2
---
FORECASTS:
12 HRS, VALID AT:
211200Z6 --- 11.3S5 143.2E0
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 040 NM OVER WATER
VECTOR TO 24 HR POSIT: 245 DEG/ 01 KTS
---
24 HRS, VALID AT:
220000Z4 --- 11.4S6 143.0E8
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
VECTOR TO 36 HR POSIT: 270 DEG/ 01 KTS
---
36 HRS, VALID AT:
221200Z7 --- 11.4S6 142.8E5
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
VECTOR TO 48 HR POSIT: 270 DEG/ 01 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
230000Z5 --- 11.4S6 142.5E2
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 060 NM OVER WATER
VECTOR TO 72 HR POSIT: 270 DEG/ 01 KTS
---
72 HRS, VALID AT:
240000Z6 --- 11.4S6 142.2E9
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
---
REMARKS:
210300Z6 POSITION 11.2S4 143.4E2.
TROPICAL CYCLONE 30P (NATHAN) HAS FORMED OFF THE EAST COAST
OF QUEENSLAND AND IS QUASI-STATIONARY. THE WARNING POSITION IS BASED ON 202330Z0
VISIBLE SATELLITE IMAGERY AND 202232Z1 MICROWAVE IMAGERY. THE WARNING INTENSITY
OF 35 KNOTS IS BASED ON A SATELLITE-DERIVED DVORAK CURRENT INTENSITY ESTIMATE
OF CI 2.5. TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO REMAIN ALMOST QUASI-
STATIONARY THROUGH THE FORECAST PERIOD, DRIFTING ONLY VERY SLOWLY TO THE WEST
UNDER THE INFLUENCE OF WEAK STEERING FLOW NORTH OF THE SUBTROPICAL RIDGE.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 210000Z IS 18 FEET. NEXT WARNINGS AT 210900Z2
(DTG 210751Z6), 211500Z9 (DTG 211351Z3), 212100Z6 (DTG 211951Z9), AND 220300Z7
(DTG 220151Z1). THIS WARNING SUPERSEDES AND CANCELS NAVPACMETOCCEN WEST GU
200521Z MAR 98 TROPICAL CYCLONE FORMATION ALERT (WTPS21 PGTW 200530) REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR SIX-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980321 0:90z0
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 002
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
210600Z9 --- 11.3S5 143.2E0
MOVEMENT PAST SIX HOURS - 245 DEGREES AT 02 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
REPEAT POSIT: 11.3S5 143.2E0
---
FORECASTS:
12 HRS, VALID AT:
211800Z2 --- 11.3S5 143.0E8
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 040 NM OVER WATER
VECTOR TO 24 HR POSIT: 270 DEG/ 00 KTS
---
24 HRS, VALID AT:
220600Z0 --- 11.3S5 142.9E6
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
VECTOR TO 36 HR POSIT: 270 DEG/ 01 KTS
---
36 HRS, VALID AT:
221800Z3 --- 11.3S5 142.7E4
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
VECTOR TO 48 HR POSIT: 270 DEG/ 01 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
230600Z1 --- 11.3S5 142.5E2
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 060 NM OVER WATER
VECTOR TO 72 HR POSIT: 270 DEG/ 01 KTS
---
72 HRS, VALID AT:
240600Z2 --- 11.3S5 142.2E9
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
---
REMARKS:
210900Z2 POSITION 11.3S5 143.2E0.
TROPICAL CYCLONE 30P (NATHAN) HAS BEEN QUASI-STATIONARY OVER THE PAST SIX HOURS.
THE WARNING POSITION IS BASED ON 210530Z1 VISIBLE SATELLITE IMAGERY. THE WARNING
INTENSITY IS BASED ON A SATELLITE-DERIVED DVORAK CURRENT INTENSITY ESTIMATE OF
CI2.5. THE SYSTEM IS FORECAST TO DRIFT SLOWLY WESTWARD UNDER THE INFLUENCE OF
WEAK STEERING FLOW NORTH OF THE SUBTROPICAL RIDGE. THE AUSTRALIAN BUREAU OF
METEOROLOGY IS CURRENTLY DEPICTING A SLIGHTLY MORE INTENSE SYSTEM WITH A VERY
SLOW SOUTHEASTWARD DRIFT. HOWEVER, WE ARE BOTH IN AGREEMENT THAT THE CYCLONE
WILL REMAIN ALMOST STATIONARY OVER THE NEXT TWO DAYS. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 210600Z IS 18 FEET. NEXT WARNINGS AT 211500Z9 (DTG 211351Z3), 212100Z6
(DTG 211951Z9), 220300Z7 (DTG 220151Z1), AND 220900Z3 (DTG 220751Z7). REFER
TO TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR SIX-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980321 15:00z
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 003 RELOCATED
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
211200Z6 --- 12.1S4 144.2E1
MOVEMENT PAST SIX HOURS - 145 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 045 NM
REPEAT POSIT: 12.1S4 144.2E1
---
FORECASTS:
12 HRS, VALID AT:
220000Z4 --- 12.5S8 144.4E3
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 24 HR POSIT: 160 DEG/ 02 KTS
---
24 HRS, VALID AT:
221200Z7 --- 12.8S1 144.5E4
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 36 HR POSIT: 180 DEG/ 02 KTS
---
36 HRS, VALID AT:
230000Z5 --- 13.2S6 144.5E4
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 010 NM
RADIUS OF 035 KT WINDS - 060 NM
VECTOR TO 48 HR POSIT: 225 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231200Z8 --- 13.5S9 144.2E1
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 015 NM
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
VECTOR TO 72 HR POSIT: 230 DEG/ 02 KTS
---
72 HRS, VALID AT:
241200Z9 --- 14.1S6 143.5E3
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 025 NM SOUTHEAST SEMICIRCLE
OVER WATER
020 NM ELSEWHERE OVER WATER
RADIUS OF 035 KT WINDS - 070 NM SOUTHEAST SEMICIRCLE
OVER WATER
045 NM ELSEWHERE OVER WATER
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTH-SOUTHEASTWARD
AT 04 KNOTS. THE WARNING POSITION IS RELOCATED BASED ON
REANALYSIS OF INFRARED SATELLITE IMAGERY AND 211116Z2
MICROWAVE IMAGERY. THE WARNING INTENSITY IS BASED ON A
SATELLITE-DERIVED DVORAK CURRENT INTENSITY ESTIMATE OF CI2.5.
TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO CONTINUE MOVING
SLOWLY TOWARD THE SOUTH-SOUTHEAST THROUGH 24 HOURS. THE WEAK
ENVIRONMENTAL STEERING FLOW OF A MID- TO LOWER-LEVEL RIDGE TO
ITS EAST IS EXPECTED TO BECOME DOMINATED BY A BUILDING
SUBTROPICAL RIDGE SOUTH OF THE SYSTEM, RESULTING IN A TURN
TOWARD THE SOUTHWEST AFTER 24 HOURS. THIS SYSTEM IS FORECAST
TO SLOWLY INTENSIFY THROUGHOUT THE FORECAST PERIOD. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 211200Z6 IS 18 FEET. NEXT WARNINGS
AT 212100Z6 (DTG 211951Z9), 220300Z7 (DTG 220151Z1), 220900Z3
(DTG 220751Z7), 221500Z0. REFER TO TROPICAL CYCLONE 29P (YALI)
WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980321 21:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 004
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
211800Z2 --- 12.2S5 144.3E2
MOVEMENT PAST SIX HOURS - 135 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 040 NM
REPEAT POSIT: 12.2S5 144.3E2
---
FORECASTS:
12 HRS, VALID AT:
220600Z0 --- 12.5S8 144.5E4
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 040 NM
VECTOR TO 24 HR POSIT: 180 DEG/ 02 KTS
---
24 HRS, VALID AT:
221800Z3 --- 12.9S2 144.5E4
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 36 HR POSIT: 200 DEG/ 02 KTS
---
36 HRS, VALID AT:
230600Z1 --- 13.2S6 144.4E3
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 48 HR POSIT: 225 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
231800Z4 --- 13.5S9 144.1E0
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 015 NM
RADIUS OF 035 KT WINDS - 060 NM OVER WATER
VECTOR TO 72 HR POSIT: 230 DEG/ 02 KTS
---
72 HRS, VALID AT:
241800Z5 --- 14.1S6 143.3E1
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 020 NM SOUTHEAST SEMICIRCLE
OVER WATER
010 NM ELSEWHERE OVER WATER
RADIUS OF 035 KT WINDS - 065 NM SOUTHEAST SEMICIRCLE
OVER WATER
035 NM ELSEWHERE OVER WATER
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTHEASTWARD
AT 03 KNOTS. THE WARNING POSITION AND INTENSITY ARE BASED ON
211732Z6 INFRARED SATELLITE IMAGERY. ANIMATED INFRARED SATELLITE
IMAGERY SHOWS THIS SYSTEM HAS MAINTAINED ITS INTENSITY OVER THE
PAST 06 HOURS THOUGH CLOUD TOPS HAVE WARMED SLIGHTLY. NO CHANGE
TO FORECAST REASONING. THIS SYSTEM IS FORECAST TO CONTINUE MOVING
GENERALLY SOUTHEASTWARD THROUGH 12 HOURS UNDER THE ENVIRONMENTAL
STEERING INFLUENCE OF MID- TO LOWER-LEVEL RIDGING TO ITS EAST.
AFTER 12 HOURS A STRENGTHENING MID-LEVEL ANTICYCLONE TO ITS SOUTH
IS EXPECTED TO TURN TROPICAL CYCLONE 30P (NATHAN) TOWARD THE
SOUTHWEST. THIS SYSTEM IS ANTICIPATED TO MAKE LANDFALL OVER THE
CAPE YORK PENINSULA BETWEEN THE 48 AND 72 HOUR FORECAST
POSITIONS. TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO INTENSIFY
SLOWLY THROUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 211800Z2 IS 18 FEET. NEXT WARNINGS AT 220300Z7 (DTG
220151Z1), 220900Z3 (DTG 220751Z7), 221500Z0 (DTG 221351Z4) AND
222100Z7 (DTG 221951Z0). REFER TO TROPICAL CYCLONE 29P (YALI)
WARNINGS (WTPS33 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980322 03:00z
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 005 RELOCATED
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
220000Z4 --- 11.6S8 145.0E0
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 040 NM
REPEAT POSIT: 11.6S8 145.0E0
---
FORECASTS:
12 HRS, VALID AT:
221200Z7 --- 11.6S8 145.4E4
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 040 NM
VECTOR TO 24 HR POSIT: 105 DEG/ 02 KTS
---
24 HRS, VALID AT:
230000Z5 --- 11.7S9 145.8E8
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 36 HR POSIT: 155 DEG/ 02 KTS
---
36 HRS, VALID AT:
231200Z8 --- 12.1S4 146.0E1
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 48 HR POSIT: 180 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
240000Z6 --- 12.5S8 146.0E1
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 060 NM
VECTOR TO 72 HR POSIT: 220 DEG/ 02 KTS
---
72 HRS, VALID AT:
250000Z7 --- 13.1S5 145.5E5
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 065 NM
---
REMARKS:
220300Z7 POSITION 11.6S8 145.1E1.
TROPICAL CYCLONE 30P (NATHAN) IS MOVING EASTWARD AT 03 KNOTS. THE
WARNING POSITION IS BASED ON 212330Z1 VISIBLE SATELLITE IMAGERY AND
212219Z7 MICROWAVE IMAGERY. THE WARNING INTENSITY OF 40 KNOTS IS BASED
ON A COMPROMISE OF SATELLITE-DERIVED DVORAK CURRENT INTENSITY
ESTIMATES RANGING BETWEEN CI2.5 (35 KNOTS) AND CI3.5 (55 KNOTS). THE
SYSTEM WAS RELOCATED BASED ON THE FIRST VISIBLE SATELLITE IMAGERY OF
THE DAY INDICATING THAT NATHAN=S LOW-LEVEL CIRCULATION CENTER IS
ACTUALLY LOCATED TO THE NORTHWEST OF THE DEEP CONVECTION. THIS
SHEARING IS EXPECTED TO BE TEMPORARY, AND WE HAVE FORECAST THE CYCLONE
TO CONTINUE INTENSIFYING. TROPICAL CYCLONE 30P (NATHAN) IS CURRENTLY
UNDER WEAK ENVIRONMENTAL STEERING AND IS EXPECTED TO BEGIN A GRADUAL
TURN AS THE RIDGE SOUTH OF THE SYSTEM BUILDS. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 220000Z IS 16 FEET. NEXT WARNINGS AT 220900Z3 (DTG
220751Z7), 221500Z0 (DTG 221351Z4), 2222100Z7 (DTG 221951Z0), AND
230300Z8 (DTG 230151Z2). REFER TO TROPICAL CYCLONE
29P (YALI) WARNINGS (WTPS31 PGTW) FOR SIX-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980322 09:00z COR
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 006A CORRECTED
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
220600Z0 --- 11.9S1 145.2E2
MOVEMENT PAST SIX HOURS - 135 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 040 NM
REPEAT POSIT: 11.9S1 145.2E2
---
FORECASTS:
12 HRS, VALID AT:
221800Z3 --- 12.2S5 145.5E5
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 040 NM
VECTOR TO 24 HR POSIT: 145 DEG/ 02 KTS
---
24 HRS, VALID AT:
230600Z1 --- 12.5S8 145.7E7
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 36 HR POSIT: 180 DEG/ 02 KTS
---
36 HRS, VALID AT:
231800Z4 --- 12.8S1 145.6E6
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 48 HR POSIT: 225 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
240600Z2 --- 13.1S5 145.3E3
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 060 NM
VECTOR TO 72 HR POSIT: 225 DEG/ 02 KTS
---
72 HRS, VALID AT:
250600Z3 --- 13.6S0 144.8E7
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
---
REMARKS:
220900Z3 POSITION 12.0S3 145.3E3.
TROPICAL CYCLONE 30P (NATHAN) IS TRACKING SOUTHEASTWARD AT
03 KNOTS. THE WARNING POSITION AND INTENSITY ARE BASED ON
220530Z2 VISIBLE SATELLITE IMAGERY. THERE IS NO SIGNIFICANT
CHANGE TO THE FORECAST TRACK SINCE THE PREVIOUS WARNING. THE
SUBTROPICAL RIDGE SOUTH OF THE SYSTEM IS EXPECTED TO EVENTUALLY
CAUSE TC 30P (NATHAN) TO DRIFT BACK TO THE WEST. TROPICAL
CYCLONE 30P (NATHAN) IS FORECAST TO SLOWLY INTENSIFY THROUGHOUT
THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 220600Z
IS 10 FEET. NEXT WARNINGS AT 221500Z0 (DTG 221351Z4), 222100Z7
(DTG 221951Z0), 230300Z8 (DTG 230151Z2), AND 230900Z4 (DTG
230751Z8). REFER TO TROPICAL CYCLONE 29P (YALI) WARNINGS
(WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES. JUSTIFICATION FOR
CORRECTION: TO CHANGE TC 29P (YALI) HEADER FROM (WTPS33 PGTW)
TO (WTPS31 PGTW) AND ITS WARNING INTERVAL FROM SIX-HOURLY TO
TWELVE-HOURLY.//
=========================================================================
WTPS32 PGTW 980322 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 007
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
221200Z7 --- 12.5S8 145.6E6
MOVEMENT PAST SIX HOURS - 145 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 050 NM
REPEAT POSIT: 12.5S8 145.6E6
---
FORECASTS:
12 HRS, VALID AT:
230000Z5 --- 12.9S2 145.8E8
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 24 HR POSIT: 195 DEG/ 02 KTS
---
24 HRS, VALID AT:
231200Z8 --- 13.3S7 145.7E7
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 36 HR POSIT: 215 DEG/ 02 KTS
---
36 HRS, VALID AT:
240000Z6 --- 13.7S1 145.4E4
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 065 NM
VECTOR TO 48 HR POSIT: 245 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
241200Z9 --- 13.9S3 145.0E0
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 010 NM
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
VECTOR TO 72 HR POSIT: 250 DEG/ 02 KTS
---
72 HRS, VALID AT:
251200Z0 --- 14.1S6 144.4E3
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 015 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTHEASTWARD AT
04 KNOTS. THE WARNING POSITION AND INTENSITY ARE BASED ON
221130Z9 INFRARED SATELLITE IMAGERY. ANIMATED INFRARED
SATELLITE IMAGERY SHOWS THIS SYSTEM HAS INCREASED ITS CON-
VECTIVE ORGANIZATION OVER THE PAST 06 HOURS AND CLOUD TOP
TEMPERATURES HAVE COOLED SLIGHTLY. ENVIRONMENTAL STEERING
FLOW REMAINS WEAK. THERE IS NO CHANGE TO PREVIOUS FORECAST
REASONING. TROPICAL CYCLONE 30P (NATHAN) IS EXPECTED TO
TURN TOWARD THE SOUTHWEST AFTER 12 HOURS AS THE SUBTROPICAL
RIDGE TO ITS SOUTH STRENGTHENS. THIS SYSTEM IS FORECAST
TO SLOWLY INTENSIFY THROUGHOUT THE FORECAST PERIOD.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221200Z7 IS 18 FEET.
NEXT WARNINGS AT 222100Z7 (DTG 221951Z0), 230300Z8 (DTG
230151Z2), 230900Z4 (DTG 230751Z8) AND 231500Z1 (DTG
231351Z5). REFER TO TROPICAL CYCLONE 29P (YALI) WARNINGS
(WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980322 21:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 008
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
221800Z3 --- 12.8S1 145.7E7
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 050 NM
REPEAT POSIT: 12.8S1 145.7E7
---
FORECASTS:
12 HRS, VALID AT:
230600Z1 --- 13.3S7 145.8E8
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 24 HR POSIT: 205 DEG/ 02 KTS
---
24 HRS, VALID AT:
231800Z4 --- 13.7S1 145.6E6
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 060 NM
VECTOR TO 36 HR POSIT: 245 DEG/ 02 KTS
---
36 HRS, VALID AT:
240600Z2 --- 13.9S3 145.2E2
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 010 NM
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
VECTOR TO 48 HR POSIT: 255 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
241800Z5 --- 14.0S5 144.8E7
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 015 NM
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
VECTOR TO 72 HR POSIT: 255 DEG/ 02 KTS
---
72 HRS, VALID AT:
251800Z6 --- 14.2S7 144.1E0
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTHWARD AT 03 KNOTS.
THE WARNING POSITION AND INTENSITY ARE BASED ON 221730Z5 INFRARED
SATELLITE IMAGERY. THIS SYSTEM HAS INTENSIFIED SLIGHTLY OVER THE
PAST 06 HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS AN
INCREASE IN THE ORGANIZATION OF DEEP CONVECTION NEAR THE SYSTEM
CENTER. CLOUD TOPS HAVE COOLED DURING THE PAST 03 HOURS. NO
CHANGE TO FORECAST REASONING. TROPICAL CYCLONE 30P (NATHAN) IS
EXPECTED TO TURN TOWARD THE SOUTHWEST AFTER THE 12 HOUR FORECAST
POSITION IN RESPONSE TO THE SUBTROPICAL RIDGE STRENGTHENING TO
ITS SOUTH. THIS SYSTEM IS FORECAST TO INTENSIFY SLOWLY THROUGHOUT
THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221800Z3
IS 18 FEET. NEXT WARNINGS AT 230300Z8 (DTG 230151Z2), 230900Z4
(DTG 230751Z8), 231500Z1 (DTG 231351Z5) AND 232100Z8 (DTG
231951Z6). REFER TO TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31
PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980323 03:00z
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 009
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
230000Z5 --- 13.4S8 145.6E6
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 050 NM
REPEAT POSIT: 13.4S8 145.6E6
---
FORECASTS:
12 HRS, VALID AT:
231200Z8 --- 13.6S0 145.5E5
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 025 NM
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 24 HR POSIT: 205 DEG/ 01 KTS
---
24 HRS, VALID AT:
240000Z6 --- 13.8S2 145.4E4
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 025 NM
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 36 HR POSIT: 215 DEG/ 02 KTS
---
36 HRS, VALID AT:
241200Z9 --- 14.1S6 145.2E2
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 025 NM
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
VECTOR TO 48 HR POSIT: 225 DEG/ 01 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
250000Z7 --- 14.3S8 145.0E0
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
VECTOR TO 72 HR POSIT: 225 DEG/ 01 KTS
---
72 HRS, VALID AT:
260000Z8 --- 14.5S0 144.8E7
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
---
REMARKS:
230300Z8 POSITION 13.5S9 145.6E6.
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTHWARD AT 04 KNOTS. THE
WARNING POSITION IS BASED ON 222330Z2 VISIBLE SATELLITE IMAGERY,
221932Z9 MICROWAVE IMAGERY, AND AVAILABLE SYNOPTIC DATA. THE WARNING
INTENSITY OF 55 KNOTS IS BASED IS BASED ON A SATELLITE-DERIVED
DVORAK CURRENT INTENSITY ESTIMATE OF CI3.5. TROPICAL CYCLONE 30P
(NATHAN) IS EXPECTED TO CONTINUE TRACKING SLOWLY SOUTHWESTWARD
THROUGHOUT THE FORECAST PERIOD UNDER WEAK ENVIRONMENTAL STEERING
FLOW. THE SYSTEM IS EXPECTED TO SLOWLY INTENSIFY. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 230000Z IS 18 FEET. NEXT WARNINGS AT
230900Z4 (DTG 230751Z8), 231500Z1 (DTG 231351Z5), 232100Z7 (DTG
231951Z1) AND 240300Z9 (DTG 240151Z3). REFER TO TROPICAL CYCLONE 29P
(YALI) WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980323 09:00z
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 010
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
230600Z1 --- 13.7S1 145.4E4
MOVEMENT PAST SIX HOURS - 215 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 050 NM
REPEAT POSIT: 13.7S1 145.4E4
---
FORECASTS:
12 HRS, VALID AT:
231800Z4 --- 13.8S2 145.3E3
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 025 NM
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 24 HR POSIT: 225 DEG/ 01 KTS
---
24 HRS, VALID AT:
240600Z2 --- 14.0S5 145.1E1
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 055 NM OVER WATER
VECTOR TO 36 HR POSIT: 225 DEG/ 01 KTS
---
36 HRS, VALID AT:
241800Z5 --- 14.1S6 145.0E0
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
VECTOR TO 48 HR POSIT: 225 DEG/ 01 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
250600Z3 --- 14.2S7 144.9E8
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 065 NM OVER WATER
VECTOR TO 72 HR POSIT: 225 DEG/ 01 KTS
---
72 HRS, VALID AT:
260600Z4 --- 14.5S0 144.6E5
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM OVER WATER
---
REMARKS:
230900Z4 POSITION 13.7S1 145.4E4.
TROPICAL CYCLONE 30P (NATHAN) IS TRACKING SOUTHWESTWARD AT 04 KNOTS. THE
WARNING POSITION IS BASED ON 230530Z3 VISIBLE SATELLITE IMAGERY AND AVAILABLE
SYNOPTIC DATA. THE WARNING INTENSITY OF 55 KNOTS IS BASED ON A COMBINATION OF
A SATELLITE DERIVED DVORAK CURRENT INTENSITY ESTIMATE OF CI4.0 (65 KNOTS) AND
CI3.0 (45 KNOTS). NO SIGNIFICANT CHANGE TO FORECAST TRACK AND INTENSITY. THE
SYSTEM IS UNDER WEAK ENVIRONMENTAL STEERING AND CONTINUED SLOW MOVEMENT TO THE
SOUTHWEST. TROPICAL CYCLONE 30P (NATHAN) REMAINS IN AN ENVIRONMENT FOR SLOW
INTENSIFICATION THROUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 230600Z IS 11 FEET. NEXT WARNINGS AT 231500Z1 (DTG 231351Z5), 232100Z8
(DTG 231951Z1), 240300Z9 (DTG 240151Z3), AND 240900Z5 (DTG 240751Z9). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY
UPDATES.//
=========================================================================
WTPS32 PGTW 980323 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 011
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
231200Z8 --- 14.1S6 145.6E6
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
REPEAT POSIT: 14.1S6 145.6E6
---
FORECASTS:
12 HRS, VALID AT:
240000Z6 --- 14.5S0 145.7E7
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
VECTOR TO 24 HR POSIT: 215 DEG/ 02 KTS
---
24 HRS, VALID AT:
241200Z9 --- 14.8S3 145.5E5
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM
RADIUS OF 035 KT WINDS - 050 NM OVER WATER
VECTOR TO 36 HR POSIT: 235 DEG/ 02 KTS
---
36 HRS, VALID AT:
250000Z7 --- 15.0S6 145.2E2
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 055 NM OVER WATER
VECTOR TO 48 HR POSIT: 250 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
251200Z0 --- 15.1S7 144.9E8
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 055 NM OVER WATER
VECTOR TO 72 HR POSIT: 260 DEG/ 02 KTS
---
72 HRS, VALID AT:
261200Z1 --- 15.2S8 144.2E1
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 050 KT WINDS - 020 NM OVER WATER
RADIUS OF 035 KT WINDS - 070 NM SOUTHEAST SEMICIRCLE
OVER WATER
045 NM ELSEWHERE OVER WATER
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) CONTINUES TO MOVE SOUTHWARD AT 04
KNOTS IN WEAK ENVIRONMENTAL STEERING. THE WARNING POSITION AND
INTENSITY ARE BASED ON 221130Z9 INFRARED SATELLITE IMAGERY
AUGMENTED BY 221047Z6 MICROWAVE DATA. THIS SYSTEM HAS INTEN-
SIFIED OVER THE PAST 06 HOURS. ANIMATED INFRARED SATELLITE
IMAGERY SHOWS UPPER-LEVEL OUTFLOW IS GOOD IN ALL QUADRANTS.
TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO CONTINUE MOVING
GENERALLY SOUTHWARD THROUGH TWELVE HOURS THEN TURN TOWARD THE
WEST-SOUTHWEST AND MAKE LANDFALL OVER NORTHEASTERN QUEENSLAND.
IT IS ANTICIPATED THAT A STRENGTHENING SUBTROPICAL RIDGE SOUTH
OF THIS SYSTEM WILL BECOME THE DOMINANT ENVIRONMENTAL STEERING
INFLUENCE AFTER 12 HOURS. THIS SYSTEM IS EXPECTED TO INTENSIFY
SLOWLY PRIOR TO MAKING LANDFALL, THEN SLOWLY WEAKEN. AN ALTERNATE
TRACK IS SUGGESTED BY SEVERAL DYNAMIC AND STATISTICAL OBJECTIVE
FORECAST AIDS, IN WHICH TROPICAL CYCLONE 30P (NATHAN) CONTINUES
TO MOVE SLOWLY TO THE SOUTHEAST IN WEAK STEERING FLOW. THE
PROBABILITY OF THIS ALTERNATE SCENARIO IS LOW. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 231200Z8 IS 18 FEET. NEXT WARNINGS AT 232100Z8
(DTG 231951Z1), 240300Z9 (DTG 240151Z3), 240900Z5 (DTG 240751Z9)
AND 241500Z2 (DTG 241351Z6). REFER TO TROPICAL CYCLONE 29P (YALI)
WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980323 21:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 012
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
231800Z4 --- 14.5S0 145.8E8
MOVEMENT PAST SIX HOURS - 160 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM
REPEAT POSIT: 14.5S0 145.8E8
---
FORECASTS:
12 HRS, VALID AT:
240600Z2 --- 14.9S4 145.8E8
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM OVER WATER
VECTOR TO 24 HR POSIT: 225 DEG/ 01 KTS
---
24 HRS, VALID AT:
241800Z5 --- 15.1S7 145.6E6
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 050 NM OVER WATER
VECTOR TO 36 HR POSIT: 245 DEG/ 02 KTS
---
36 HRS, VALID AT:
250600Z3 --- 15.3S9 145.2E2
MAX SUSTAINED WINDS - 070 KT, GUSTS 080 KT
RADIUS OF 050 KT WINDS - 025 NM OVER WATER
RADIUS OF 035 KT WINDS - 055 NM OVER WATER
VECTOR TO 48 HR POSIT: 245 DEG/ 03 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
251800Z6 --- 15.5S1 144.7E6
MAX SUSTAINED WINDS - 065 KT, GUSTS 075 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 050 KT WINDS - 025 NM SOUTHEAST SEMICIRCLE
OVER WATER
015 NM ELSEWHERE OVER WATER
RADIUS OF 035 KT WINDS - 055 NM SOUTHEAST SEMICIRCLE
OVER WATER
035 NM ELSEWHERE OVER WATER
VECTOR TO 72 HR POSIT: 255 DEG/ 02 KTS
---
72 HRS, VALID AT:
261800Z7 --- 15.7S3 144.0E9
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 050 KT WINDS - 010 NM OVER WATER
RADIUS OF 035 KT WINDS - 050 NM SOUTHEAST SEMICIRCLE
OVER WATER
030 NM ELSEWHERE OVER WATER
---
REMARKS:
232100Z8 POSITION 14.6S1 145.8E8.
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTH-SOUTHEASTWARD AT 03
KNOTS. THE WARNING POSITION AND INTENSITY ARE BASED ON 231730Z6
INFRARED SATELLITE IMAGERY. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS THIS SYSTEM HAS MAINTAINED ITS INTENSITY OVER THE PAST 06
HOURS THOUGH OUTFLOW HAS BECOME SLIGHTLY RESTRICTED IN THE
NORTHEAST QUADRANT. TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO
BEGIN RECURVING AT THE 12 HOUR FORECAST POSITION AND MAKE LANDFALL
OVER NORTHEASTERN QUEENSLAND BY 36 HOURS. THIS SYSTEM IS
EXPECTED TO INTENSIFY SLOWLY PRIOR TO LANDFALL THEN WEAKEN
SLOWLY. THE SUBTROPICAL RIDGE SOUTH OF THIS SYSTEM IS ANTICIPATED
TO BECOME THE DOMINANT ENVIRONMENTAL STEERING INFLUENCE. SEVERAL
DYNAMIC AND THE MAJORITY OF STATISTICAL AND CLIMATOLOGICAL
FORECAST AIDS SUGGEST AN ALTERNATE SCENARIO IN WHICH TROPICAL
CYCLONE 30P (NATHAN) MOVES SLOWLY TO THE SOUTHEAST THROUGH 72
HOURS. THE PROBABILITY OF THIS ALTERNATE FORECAST SCENARIO IS
MODERATE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231800Z4 IS 19 FEET.
NEXT WARNINGS AT 240300Z9 (DTG 240151Z3), 240900Z5 (DTG 40751Z9),
241500Z9 (DTG 241351Z6) AND 242100Z9 (DTG 241951Z2). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR TWELVE-
HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980324 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 013
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
240000Z6 --- 14.8S3 146.6E7
MOVEMENT PAST SIX HOURS - 115 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 060 KT, GUSTS 070 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM
REPEAT POSIT: 14.8S3 146.6E7
---
FORECASTS:
12 HRS, VALID AT:
241200Z9 --- 15.0S6 147.1E3
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM
VECTOR TO 24 HR POSIT: 115 DEG/ 03 KTS
---
24 HRS, VALID AT:
250000Z7 --- 15.2S8 147.6E8
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 36 HR POSIT: 115 DEG/ 03 KTS
---
36 HRS, VALID AT:
251200Z0 --- 15.4S0 148.1E4
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 48 HR POSIT: 110 DEG/ 03 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
260000Z8 --- 15.6S2 148.7E0
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 72 HR POSIT: 115 DEG/ 03 KTS
---
72 HRS, VALID AT:
270000Z9 --- 16.0S7 149.7E1
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 050 NM
---
REMARKS:
240300Z9 POSITION 14.8S3 146.7E8.
TROPICAL CYCLONE 30P (NATHAN) IS MOVING SOUTHEASTWARD AT 05
KNOTS. THE WARNING POSITION IS BASED ON 232330Z3 VISIBLE
SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON A
232330Z3 SATELLITE DVORAK INTENSITY ESTIMATE OF 60 KNOTS.
ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT TROPICAL
CYCLONE 30P (NATHAN) HAS BECOME SLIGHTLY LESS ORGANIZED AND
SLOWED OVER THE PAST 12 HOURS. ADDITIONALLY, THE SYSTEM HAS
WEAKENED SLIGHTLY. A TROUGH OF LOW PRESSURE EAST OF THE
SYSTEM IS SERVING AS THE PRIMARY STEERING FLOW. DIRECT
INTERACTION WITH TROPICAL CYCLONE 29P (YALI) IS EXPECTED TO
GREATLY INFLUENCE THE SYSTEM'S TRACK AND INTENSITY OVER THE
FORECAST PERIOD. TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO
CONTINUE ON A SOUTHEASTWARD TRACK AT A FORWARD SPEED OF 03
KNOTS FOR THE 72-HOUR PERIOD. INTENSITY IS EXPECTED TO SLOWLY
DECREASE THROUGHOUT THE PERIOD AS WELL. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 240000Z6 IS 19 FEET. NEXT WARNINGS AT 240900Z
(DTG 240751Z9), 241500Z2 (DTG 241351Z6), 242100Z9 (DTG
241951Z2) AND 250300Z0 (DTG 250151Z4). REFER TO TROPICAL
CYCLONE 29P (YALI) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980324 09:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 014
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
240600Z2 --- 14.6S1 147.7E9
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM
REPEAT POSIT: 14.6S1 147.7E9
---
FORECASTS:
12 HRS, VALID AT:
241800Z5 --- 14.7S2 148.4E7
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM
VECTOR TO 24 HR POSIT: 100 DEG/ 03 KTS
---
24 HRS, VALID AT:
250600Z3 --- 14.8S3 149.0E4
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 050 NM
VECTOR TO 36 HR POSIT: 100 DEG/ 03 KTS
---
36 HRS, VALID AT:
251800Z6 --- 14.9S4 149.6E0
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 48 HR POSIT: 110 DEG/ 03 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
260600Z4 --- 15.1S7 150.2E8
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 72 HR POSIT: 120 DEG/ 03 KTS
---
72 HRS, VALID AT:
270600Z5 --- 15.7S3 151.4E1
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 050 NM
---
REMARKS:
240900Z5 POSITION 14.6S1 147.9E1.
TROPICAL CYCLONE 30P (NATHAN) IS TRACKING EASTWARD AT A SPEED
OF 07 KNOTS. THE WARNING POSITION IS BASED ON 240530Z4
VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON
A 240530Z4 SATELLITE DVORAK INTENSITY ESTIMATE OF 55 KNOTS.
FOR THE PAST 6 HOURS, THE SYSTEM HAS TRACKED SLOWLY TOWARDS
THE EAST WITH NO SIGNIFICANT CHANGE IN INTENSITY. THE
FORECAST REMAINS THE SAME AS THE SYSTEM IS EXPECTED TO
CONTINUE TO TRACK EASTWARD AT 03 KNOTS AND THE INTENSITY IS
FORECAST TO GRADUALLY DECREASE THROUGHOUT THE 72-HOUR PERIOD.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 240600Z2 IS 17 FEET. NEXT
WARNINGS AT 241500Z2 (DTG 241351Z6), 242100Z9 (DTG 241951Z2),
250300Z0 (DTG 250151Z4) AND 250900Z6 (DTG 250751Z0). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR
TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980324 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 015
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
241200Z9 --- 14.1S6 148.4E7
MOVEMENT PAST SIX HOURS - 075 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM NORTH SEMICIRCLE
015 NM ELSEWHERE
RADIUS OF 035 KT WINDS - 045 NM NORTH SEMICIRCLE
040 NM ELSEWHERE
REPEAT POSIT: 14.1S6 148.4E7
---
FORECASTS:
12 HRS, VALID AT:
250000Z7 --- 13.9S3 149.6E0
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM
RADIUS OF 035 KT WINDS - 045 NM NORTH SEMICIRCLE
040 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 090 DEG/ 06 KTS
---
24 HRS, VALID AT:
251200Z0 --- 13.9S3 150.8E4
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 050 NM NORTH SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 100 DEG/ 06 KTS
---
36 HRS, VALID AT:
260000Z8 --- 14.1S6 152.0E8
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 055 NM NORTH SEMICIRCLE
050 NM ELSEWHERE
VECTOR TO 48 HR POSIT: 110 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
261200Z1 --- 14.5S0 153.1E0
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 055 NM NORTHEAST SEMICIRCLE
050 NM ELSEWHERE
VECTOR TO 72 HR POSIT: 130 DEG/ 07 KTS
---
72 HRS, VALID AT:
271200Z2 --- 16.3S0 155.4E5
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 050 NM NORTHEAST SEMICIRCLE
040 NM ELSEWHERE
---
REMARKS:
241500Z2 POSITION 14.0S5 148.7E0.
TROPICAL CYCLONE 30P (NATHAN) HAS BEEN TRACKING EAST-
NORTHEASTWARD AT 8 KNOTS FOR THE PAST 6 HOURS. WARNING POSITION
IS BASED ON 241130Z1 INFRARED SATELLITE IMAGERY. WARNING
INTENSITY IS BASED ON 241130Z1 SATELLITE INTENSITY ESTIMATE OF 65
KNOTS AND CONTINUITY WITH PREVIOUS FORECAST. TROPICAL CYCLONE 30P
(NATHAN) HAS BEEN TRACKING EAST-NORTHEASTWARD IN RESPONSE TO MID-
LEVEL STEERING FLOW INFLUENCED BY THE PRESENCE OF TROPICAL
CYCLONE 29P (YALI) LOCATED TO THE SOUTHEAST. TROPICAL CYCLONE 30P
(NATHAN) SHOULD BEGIN A MORE EASTWARD TRACK BY THE 12 HOUR
POSITION AND CONTINUE THROUGH THE 24 HOUR POSITION. AFTER THE 24
HOUR POSITION, THE SYSTEM SHOULD BEGIN A MORE EAST-SOUTHEASTWARD
TRACK AGAIN INFLUENCED BY THE PRESENCE OF TROPICAL CYCLONE 29P
(YALI). TROPICAL CYCLONE 30P (NATHAN) SHOULD BEGIN TO SLOWLY
DECREASE IN INTENSITY BY THE 24 HOUR POSITION. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 241200Z9 IS 17 FEET. NEXT WARNINGS AT
242100Z9 (DTG 241951Z2), 250300Z0 (DTG 250151Z4), 250900Z6 (DTG
250751Z0) AND 251500Z3 (DTG 251351Z7). REFER TO TROPICAL
CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY
UPDATES.//
=========================================================================
WTPS32 PGTW 980324 21:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 016
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
241800Z5 --- 13.4S8 149.5E9
MOVEMENT PAST SIX HOURS - 065 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM NORTHWEST SEMICIRCLE
015 NM ELSEWHERE
RADIUS OF 035 KT WINDS - 050 NM NORTHWEST SEMICIRCLE
045 NM ELSEWHERE
REPEAT POSIT: 13.4S8 149.5E9
---
FORECASTS:
12 HRS, VALID AT:
250600Z3 --- 12.9S2 150.8E4
MAX SUSTAINED WINDS - 055 KT, GUSTS 065 KT
RADIUS OF 050 KT WINDS - 020 NM NORTHWEST SEMICIRCLE
015 NM ELSEWHERE
RADIUS OF 035 KT WINDS - 050 NM NORTHWEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 075 DEG/ 07 KTS
---
24 HRS, VALID AT:
251800Z6 --- 12.6S9 152.1E9
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 050 NM NORTH SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 095 DEG/ 07 KTS
---
36 HRS, VALID AT:
260600Z4 --- 12.7S0 153.5E4
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 045 NM NORTH SEMICIRCLE
040 NM ELSEWHERE
VECTOR TO 48 HR POSIT: 110 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
261800Z7 --- 13.2S6 154.8E8
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 045 NM NORTHEAST SEMICIRCLE
040 NM ELSEWHERE
VECTOR TO 72 HR POSIT: 125 DEG/ 08 KTS
---
72 HRS, VALID AT:
271800Z8 --- 14.9S4 157.5E8
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 045 NM NORTHEAST SEMICIRCLE
040 NM ELSEWHERE
---
REMARKS:
242100Z9 POSITION 13.3S7 149.8E2.
TROPICAL CYCLONE 30P (NATHAN) HAS BEEN TRACKING EAST-
NORTHEASTWARD AT 10 KNOTS FOR THE PAST 6 HOURS. WARNING POSITION
IS BASED ON 241730Z7 INFRARED SATELLITE IMAGERY. WARNING
INTENSITY IS BASED ON A 241730Z7 SATELLITE INTENSITY ESTIMATE OF
65 KNOTS AND A 241732Z9 SATELLITE INTENSITY ESTIMATE OF 45 KNOTS.
TROPICAL CYCLONE 30P (NATHAN) CONTINUES TO TRACK EAST-
NORTHEASTWARD UNDER THE INFLUENCE OF MID-LEVEL STEERING FLOW DUE
TO THE LARGE SCALE CIRCULATION AROUND TROPICAL CYCLONE 29P
(YALI). FORECAST TRACK PHILOSOPHY REMAINS THE SAME. TROPICAL
CYCLONE 30P (NATHAN) SHOULD REMAIN AT OR NEAR IT=S CURRENT
INTENSITY THROUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 241800Z IS 16 FEET. NEXT WARNINGS AT 250300Z0 (DTG
250151Z4), 250900Z6 (DTG 250751Z0), 251500Z3 (DTG 251351Z7), AND
252100Z0 (DTG 251951Z3). REFER TO TROPICAL CYCLONE 29P (YALI)
WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980325 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 017
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
250000Z7 --- 13.2S6 151.4E1
MOVEMENT PAST SIX HOURS - 080 DEGREES AT 15 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 070 NM WEST SEMICIRCLE
045 NM ELSEWHERE
REPEAT POSIT: 13.2S6 151.4E1
---
FORECASTS:
12 HRS, VALID AT:
251200Z0 --- 13.0S4 153.0E9
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 065 NM WEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 095 DEG/ 08 KTS
---
24 HRS, VALID AT:
260000Z8 --- 13.2S6 154.6E6
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 060 NM WEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 115 DEG/ 09 KTS
---
36 HRS, VALID AT:
261200Z1 --- 13.9S3 156.2E4
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM WEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 48 HR POSIT: 120 DEG/ 09 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
270000Z9 --- 14.8S3 157.8E1
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 045 NM WEST SEMICIRCLE
040 NM ELSEWHERE
VECTOR TO 72 HR POSIT: 125 DEG/ 06 KTS
---
72 HRS, VALID AT:
280000Z0 --- 16.3S0 160.0E7
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 040 NM
---
REMARKS:
250300Z0 POSITION 13.2S6 151.8E5.
ANIMATED VISIBLE SATELLITE IMAGERY INDICATES TROPICAL CYCLONE
30P (NATHAN) IS CONTINUING ON AN EASTERLY TRACK AND HAS
INCREASED ITS FORWARD SPEED TO 15 KNOTS. THE WARNING POSITION
AND INTENSITY AREA BASED ON 242330Z4 VISIBLE SATELLITE
IMAGERY. VISIBLE IMAGERY ALSO INDICATES THE SYSTEM IS
EXPERIENCING MODERATE WIND SHEER FROM THE EAST. THE FORECAST
PHILOSOPHY REMAINS SIMILAR AS THE SYSTEM IS FORECAST TO
CONTINUE ON AN EASTWARD TRACK THROUGH THE 24 HOUR PERIOD AND
THEN TURN SLIGHTLY TOWARDS THE SOUTHEAST AS THE LARGE SCALE
CIRCULATION ASSOCIATED WITH TROPICAL CYCLONE 29P (YALI) MOVES
TOWARDS THE SOUTHWEST. TROPICAL CYCLONE 30P (NATHAN) IS
EXPECTED TO MAINTAIN ITS INTENSITY THROUGH THE 12 HOUR PERIOD
AND THEN WEAKEN SLIGHTLY. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
250000Z7 IS 16 FEET. NEXT WARNINGS AT 251500Z3 (DTG
251351Z7), 252100Z3 (DTG 251951), 260300Z1 (DTG 260151Z5) AND
260900Z7 (DTG 260751). REFER TO TROPICAL CYCLONE 29P (YALI)
WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980325 09:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 018
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
250600Z3 --- 13.1S5 153.5E4
MOVEMENT PAST SIX HOURS - 085 DEGREES AT 18 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 070 NM WEST SEMICIRCLE
045 NM ELSEWHERE
REPEAT POSIT: 13.1S5 153.5E4
---
FORECASTS:
12 HRS, VALID AT:
251800Z6 --- 13.3S7 155.9E0
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 065 NM WEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 120 DEG/ 09 KTS
---
24 HRS, VALID AT:
260600Z4 --- 14.2S7 157.6E9
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 060 NM WEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 125 DEG/ 06 KTS
---
36 HRS, VALID AT:
261800Z7 --- 14.9S4 158.6E0
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM WEST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 48 HR POSIT: 120 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
270600Z5 --- 15.5S1 159.6E1
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 045 NM WEST SEMICIRCLE
040 NM ELSEWHERE
VECTOR TO 72 HR POSIT: 125 DEG/ 05 KTS
---
72 HRS, VALID AT:
280600Z6 --- 16.5S2 161.2E0
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 040 NM
---
REMARKS:
250900Z6 POSITION 13.1S5 154.1E1.
TROPICAL CYCLONE 30P (NATHAN) IS TRACKING EASTWARD AT 18
KNOTS. THE WARNING POSITION IS BASED ON 250530Z5 VISIBLE
SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON A
250530Z5 SATELLITE DVORAK INTENSITY ESTIMATE OF 50 KNOTS. FOR
THE PAST 12 HOURS, THE SYSTEM HAS BEEN INFLUENCED BY A LARGE
SCALE SYNOPTIC FEATURE TO IT=S EAST. THIS TROUGH IS EXPECTED
TO CONTINUE TO STEER TROPICAL CYCLONE 30P (NATHAN) EASTWARD
FOR THE REMAINDER OF THE PERIOD. ADDITIONALLY, THE SYSTEM=S
INTENSITY IS FORECAST TO GRADUALLY DECREASE AS IT MOVES INTO
AN AREA OF STRONGER VERTICAL WIND SHEER NEAR THE END OF THE
FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 250600Z3
IS 16 FEET. NEXT WARNINGS AT 251500Z3 (DTG 251351Z7),
252100Z0 (DTG 251951Z3), 260300Z1 (DTG 260151Z5) AND 260900Z7
(DTG 260751Z1). REFER TO TROPICAL CYCLONE 29P (YALI) WARNINGS
(WTPS31 PGTW) FOR SIX-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980325 15:00z COR
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 019A CORRECTED
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
251200Z0 --- 13.1S5 154.6E6
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 070 NM NORTH SEMICIRCLE
045 NM ELSEWHERE
REPEAT POSIT: 13.1S5 154.6E6
---
FORECASTS:
12 HRS, VALID AT:
260000Z8 --- 13.4S8 156.8E0
MAX SUSTAINED WINDS - 050 KT, GUSTS 060 KT
RADIUS OF 035 KT WINDS - 065 NM NORTH SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 115 DEG/ 09 KTS
---
24 HRS, VALID AT:
261200Z1 --- 14.1S6 158.5E9
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 060 NM NORTHEAST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 130 DEG/ 09 KTS
---
36 HRS, VALID AT:
270000Z9 --- 15.2S8 159.9E4
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 050 NM NORTHEAST SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 48 HR POSIT: 145 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
271200Z2 --- 16.5S2 160.9E6
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 045 NM NORTHEAST SEMICIRCLE
040 NM ELSEWHERE
---
REMARKS:
251500Z3 POSITION 13.2S6 155.1E2.
TROPICAL CYCLONE 30P (NATHAN) FORWARD MOTION HAS SLOWED DURING
THE PAST 06 HOURS AS IT TRACKS EASTWARD AT 12 KNOTS. THE WARNING
POSITION IS BASED UPON A 251130Z2 ENHANCED INFRARED SATELLITE
IMAGERY. THE WARNING INTENSITY IS BASED UPON A SATELLITE
INTENSITY ESTIMATE OF 45 KNOTS AND CONTINUITY WITH THE PREVIOUS
FORECAST. THE MOTION TRACK OF TROPICAL CYCLONE 30P (NATHAN)
CONTINUES TO BE INFLUENCED BY THE LARGE MID LEVEL CIRCULATION
ASSOCIATED WITH TROPICAL CYCLONE 29P (YALI). TROPICAL CYCLONE 30P
(NATHAN) SHOULD TRACK EAST-SOUTHEASTWARD DURING THE NEXT 12 HOURS
THEN TURN MORE SOUTHEASTWARD IN RESPONSE TO THE STEERING
INFLUENCE FROM TROPICAL CYCLONE 29P (YALI). THIS MOTION TRACK
SHOULD CONTINUE THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD.
ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT TROPICAL
CYCLONE 30P (NATHAN) IS EXPERIENCING LIGHT TO MODERATE VERTICAL
WIND SHEAR WHICH SHOULD CONTINUE THROUGH THE FORECAST PERIOD. AS
A RESULT, THE SYSTEM SHOULD WEAKEN SLOWLY THROUGHOUT THE PERIOD.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 251200Z IS 13 FEET. NEXT
WARNINGS AT 260300Z1 (DTG 260151Z5) AND 261500Z4 (DTG 261351Z8).
REFER TO TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW)
FOR TWELVE-HOURLY UPDATES. JUSTIFICATION: TO CORRECT THE MAXIMUM
SIGNIFICANT WAVE HEIGHT.//
=========================================================================
WTPS32 PGTW 980326 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 020
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
260000Z8 --- 13.5S9 157.3E6
MOVEMENT PAST SIX HOURS - 100 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM NORTH SEMICIRCLE
045 NM ELSEWHERE
REPEAT POSIT: 13.5S9 157.3E6
---
FORECASTS:
12 HRS, VALID AT:
261200Z1 --- 13.8S2 159.2E7
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 065 NM NORTH SEMICIRCLE
045 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 105 DEG/ 07 KTS
---
24 HRS, VALID AT:
270000Z9 --- 14.2S7 160.6E3
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 36 HR POSIT: 115 DEG/ 05 KTS
---
36 HRS, VALID AT:
271200Z2 --- 14.6S1 161.6E4
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 48 HR POSIT: 115 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
280000Z0 --- 15.1S7 162.6E5
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
260300Z1 POSITION 13.6S0 157.8E1.
TROPICAL CYCLONE 30P (NATHAN) IS TRACKING EASTWARD AT 13 KNOTS. THE
WARNING POSITION AND INTENSITY IS BASED ON 252330Z5 VISIBLE SATELLITE
IMAGERY AND A 252058Z2 MICROWAVE IMAGERY. THE LATEST SATELLITE IMAGERY
INDICATE THAT TC 30P (NATHAN) HAS AN PARTIALLY EXPOSED LOW-LEVEL CIRCULATION
CENTER. THE CONVECTION ASSOCIATED WITH THIS SYSTEM IS LOCATED 25 NM SOUTH OF THE
SYSTEM CENTER. THE SYSTEM IS EXPECTED TO CONTINUE IN A EASTWARD DIRECTION DUE TO
THE INFLUENCE OF TROPICAL CYCLONE 29P (YALI). TC 30P (NATHAN) IS EXPECTED TO
SLOWLY WEAKEN AS THE SYSTEM ENTERS AN UNFAVORABLE ENVIRONMENT FOR FURTHER
DEVELOPMENT. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 260000Z IS 13 FEET. NEXT
WARNINGS AT 261500Z4 (DTG 261351Z8) AND 270300Z2 (DTG 270151Z6). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY
UPDATES.//
=========================================================================
WTPS32 PGTW 980326 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 021
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
261200Z1 --- 13.7S1 158.3E7
MOVEMENT PAST SIX HOURS - 110 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 065 NM NORTHEAST SEMICIRCLE
040 NM ELSEWHERE
REPEAT POSIT: 13.7S1 158.3E7
---
FORECASTS:
12 HRS, VALID AT:
270000Z9 --- 14.2S7 159.4E9
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 065 NM NORTHEAST SEMICIRCLE
040 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 125 DEG/ 05 KTS
---
24 HRS, VALID AT:
271200Z2 --- 14.7S2 160.2E9
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 060 NM NORTHEAST SEMICIRCLE
035 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 140 DEG/ 04 KTS
---
36 HRS, VALID AT:
280000Z0 --- 15.3S9 160.7E4
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 48 HR POSIT: 160 DEG/ 03 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
281200Z3 --- 15.9S5 160.9E6
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) IS MOVING EAST-SOUTHEASTWARD AT 08
KNOTS. THE WARNING POSITION AND INTENSITY ARE BASED ON 261130Z3
INFRARED SATELLITE IMAGERY AUGMENTED BY 261014Z4 MICROWAVE DATA.
ANIMATED INFRARED SATELLITE IMAGERY INDICATES THIS SYSTEM HAS
MAINTAINED ITS INTENSITY OVER THE PAST 12 HOURS. 261014Z4 MICRO-
WAVE DATA SHOWS THE MAIN DEEP CONVECTIVE AREA IS NORTHWEST OF THE
LOW-LEVEL CIRCULATION CENTER. THIS SYSTEM'S MOTION IS STILL BEING
INFLUENCED BY TROPICAL CYCLONE 29P (YALI) TO ITS SOUTH. TROPICAL
CYCLONE 30P (NATHAN) IS FORECAST TO CONTINUE MOVING EAST-
SOUTHEASTWARD THROUGH 24 HOURS THEN TURN TOWARD THE SOUTH-
SOUTHEAST. A DEVELOPING RIDGE EAST OF THIS SYSTEM IS EXPECTED TO
REPLACE TROPICAL CYCLONE 29P (YALI) AS THE DOMINANT ENVIRONMENTAL
STEERING INFLUENCE AS THE LATTER SYSTEM MOVES SOUTHWARD. TROPICAL
CYCLONE 30P (NATHAN) IS ANTICIPATED TO WEAKEN SLOWLY THROUGH 48
HOURS AS IT CONTINUES TO EXPERIENCE LIGHT VERTICAL WIND SHEAR.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 261200Z1 IS 13 FEET. NEXT
WARNINGS AT 270300Z2 (270151Z6) AND 271500Z5 (271351Z9). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR TWELVE-
BT
=========================================================================
WTPS32 PGTW 980327 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 022
02 ACTIVE TROPICAL CYCLONES IN SOUTHERN HEMISPHERE
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
270000Z9 --- 15.0S6 158.8E2
MOVEMENT PAST SIX HOURS - 170 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 045 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 065 NM
REPEAT POSIT: 15.0S6 158.8E2
---
FORECASTS:
12 HRS, VALID AT:
271200Z2 --- 16.1S8 158.9E3
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 065 NM
VECTOR TO 24 HR POSIT: 175 DEG/ 05 KTS
---
24 HRS, VALID AT:
280000Z0 --- 17.0S8 159.0E5
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 060 NM
VECTOR TO 36 HR POSIT: 175 DEG/ 05 KTS
---
36 HRS, VALID AT:
281200Z3 --- 17.9S7 159.1E6
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 48 HR POSIT: 180 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
290000Z1 --- 18.9S8 159.2E7
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
270300Z2 POSITION 15.3S9 158.8E2.
TROPICAL CYCLONE 30P (NATHAN) IS TRACKING SOUTHWARD AT 07 KNOTS. THE
WARNING POSITION AND INTENSITY ARE BASED ON 262330Z6 VISIBLE
SATELLITE IMAGERY AND 262029Z1 MICROWAVE IMAGERY. THE LATEST
SATELLITE IMAGERY INDICATE THAT THE LOW-LEVEL CIRCULATION CENTER IS
COMPLETELY EXPOSED. THE MAIN CONVECTION ASSOCIATED WITH TC 30P
(NATHAN) IS TO THE WEST OF THE CIRCULATION CENTER. THE STEERING IS
STILL BEING INFLUENCED BY TROPICAL CYCLONE 29P (YALI) TO ITS SOUTH.
THE FORECAST IS FOR TC 30P (NATHAN) TO CONTINUE TRACKING SOUTHWARD
DUE TO THE BUILDING RIDGE EAST OF SYSTEM AND TC 29P (YALI) BECOMING
EXTRATROPICAL AND MOVING SOUTH. THE SYSTEM IS FORECAST TO SLOWLY
WEAKEN AS UPPER-LEVEL SHEAR INCREASES OVER THE SYSTEM. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 270000Z IS 13 FEET. NEXT WARNINGS AT
271500Z5 (DTG 271351Z9) AND 280300Z3 (DTG 280151Z7). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNINGS (WTPS31 PGTW) FOR FINAL
WARNING. //
=========================================================================
WTPS32 PGTW 980327 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 023
01 ACTIVE TROPICAL CYCLONE IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
271200Z2 --- 15.8S4 158.8E2
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 070 NM
REPEAT POSIT: 15.8S4 158.8E2
---
FORECASTS:
12 HRS, VALID AT:
280000Z0 --- 16.6S3 158.8E2
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
RADIUS OF 035 KT WINDS - 065 NM
VECTOR TO 24 HR POSIT: 185 DEG/ 05 KTS
---
24 HRS, VALID AT:
281200Z3 --- 17.5S3 158.7E1
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 060 NM
VECTOR TO 36 HR POSIT: 200 DEG/ 05 KTS
---
36 HRS, VALID AT:
290000Z1 --- 18.4S3 158.4E8
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 055 NM
VECTOR TO 48 HR POSIT: 215 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
291200Z4 --- 19.2S2 157.8E1
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
---
REMARKS:
TROPICAL CYCLONE 30P (NATHAN) CONTINUES TO MOVE SOUTHWARD AT 04
KNOTS. THE WARNING POSITION AND INTENSITY ARE BASED ON 271130Z4
INFRARED SATELLITE IMAGERY AND 270956Z9 MICROWAVE DATA. THIS
SYSTEM HAS INTENSIFIED DURING THE PAST 06 HOURS AS A CENTRAL
DENSE OVERCAST OF DEEP CONVECTION HAS REGENERATED. 270956Z9
MICROWAVE DATA INDICATES SPIRAL BANDS WRAPPING INTO A WELL-
DEFINED CIRCULATION CENTER. UPPER-LEVEL OUTFLOW IS FAIR IN ALL
QUADRANTS. TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO CONTINUE
MOVING TOWARD THE SOUTH THROUGH 24 HOURS THEN TURN TOWARD THE
SOUTHWEST. THIS SYSTEM IS STILL BEING INFLUENCED BY AN
EXTRATROPICAL LOW PRESSURE SYSTEM TO ITS SOUTH, FORMERLY TROPICAL
CYCLONE 29P (YALI). HOWEVER, A MID-LEVEL ANTICYCLONE EAST OF THIS
SYSTEM IS EXPECTED TO BECOME THE DOMINANT ENVIRONMENTAL STEERING
INFLUENCE AFTER 12 HOURS. TROPICAL CYCLONE 30P (NATHAN) IS
ANTICIPATED TO WEAKEN SLOWLY THROUGHOUT THE FORECAST PERIOD AS IT
ENTERS A REGION OF LIGHT TO MODERATE VERTICAL WIND SHEAR. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 271200Z2 IS 14 FEET. NEXT WARNINGS AT
280300Z3 (DTG 280151Z7) AND 281500Z6 (DTG 281351Z0). REFER TO
TROPICAL CYCLONE 29P (YALI) WARNING (WTPS31 PGTW) FOR THE FINAL
WARNING ON THIS SYSTEM.//
=========================================================================
WTPS32 PGTW 980328 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 024
01 ACTIVE TROPICAL CYCLONE IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
280000Z0 --- 16.1S8 158.0E4
MOVEMENT PAST SIX HOURS - 250 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM
REPEAT POSIT: 16.1S8 158.0E4
---
FORECASTS:
12 HRS, VALID AT:
281200Z3 --- 16.2S9 157.5E8
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 24 HR POSIT: 260 DEG/ 03 KTS
---
24 HRS, VALID AT:
290000Z1 --- 16.3S0 156.8E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 36 HR POSIT: 270 DEG/ 04 KTS
---
36 HRS, VALID AT:
291200Z4 --- 16.3S0 155.9E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 48 HR POSIT: 270 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
300000Z3 --- 16.3S0 154.9E9
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
---
REMARKS:
280300Z3 POSITION 16.1S8 157.9E2.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED TOWARDS THE WEST-
SOUTHWEST AT 03 KNOTS FOR THE PAST 6 HOURS. THE WARNING
POSITION IS BASED ON 272331Z8 VISIBLE SATELLITE IMAGERY. THE
WARNING INTENSITY IS BASED ON A 272331Z8 SATELLITE DVORAK
INTENSITY ESTIMATE. PREVIOUSLY, THE SYSTEM WAS UNDER THE
INFLUENCE OF A LARGE TROUGH OF LOW PRESSURE TO THE SYSTEM=S
SOUTH. HOWEVER, OVER THE PAST 6 HOURS THE SYSTEM HAS TRACKED
SLOWLY TOWARDS THE WEST-SOUTHWEST UNDER THE INFLUENCE OF HIGH
PRESSURE TO THE SOUTH. HENCE, THE FORECAST PHILOSOPHY HAS
CHANGED TO A MORE WESTERLY TRACK. THE HIGH PRESSURE RIDGE
IS EXPECTED TO CONTINUE TO DRIVE TROPICAL CYCLONE 30P (NATHAN)
WESTWARD THROUGHOUT THE FORECAST PERIOD. THE SYSTEM=S FORWARD
SPEED IS EXPECTED TO INCREASE AFTER THE 24 HOUR PERIOD.
TROPICAL CYCLONE 30P (NATHAN) IS FORECAST TO REMAIN WEAK
THROUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 280000Z0 IS 13 FEET. NEXT WARNINGS AT 281500Z6 (DTG
281351Z0) AND 290300Z4 (DTG 290151Z8).//
=========================================================================
WTPS32 PGTW 980328 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 025
01 ACTIVE TROPICAL CYCLONE IN THE SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
281200Z3 --- 16.6S3 156.8E0
MOVEMENT PAST SIX HOURS - 260 DEGREES AT 06 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
REPEAT POSIT: 16.6S3 156.8E0
---
FORECASTS:
12 HRS, VALID AT:
290000Z1 --- 16.9S6 155.6E7
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 265 DEG/ 05 KTS
---
24 HRS, VALID AT:
291200Z4 --- 17.0S8 154.5E5
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 36 HR POSIT: 270 DEG/ 07 KTS
---
36 HRS, VALID AT:
300000Z3 --- 17.0S8 153.1E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 48 HR POSIT: 270 DEG/ 09 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
301200Z6 --- 17.0S8 151.3E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
281500Z6 POSITION 16.7S4 156.5E7.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED WESTWARD AT 06 KNOTS
FOR THE PAST 06 HOURS. THE WARNING POSITION IS BASED UPON
281130Z5 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING
INTENSITY IS BASED UPON SATELLITE INTENSITY ESTIMATES OF 35
KNOTS, CONTINUITY WITH THE PREVIOUS WARNING AND THE INCREASE OF
CONVECTION DURING THE PAST 06 HOURS AS INDICATED BY ANIMATED
SATELLITE IMAGERY. HOWEVER, THERE IS STILL EVIDENCE OF LIGHT TO
MODERATE VERTICAL WIND SHEAR THAT SHOULD INHIBIT ANY MORE
DEVELOPMENT. THE SYSTEM SHOULD TRACK WESTWARD THROUGH THE
FORECAST PERIOD DUE TO HIGH PRESSURE LOCATED TO THE SOUTH AT THE
LOWER AND MIDDLE LEVELS OF THE ATMOSPHERE. HOWEVER, SOME SLOWING
WILL OCCUR AT THE 12 HOUR POSITION AS A MID-LATITUDE FRONTAL
SYSTEM APPROACHES FROM THE WEST. AFTER 24 HOURS THE SYSTEM=S
FORWARD MOTION WILL ONCE AGAIN INCREASE AS HIGH PRESSURE BUILDS
IN THE WAKE OF THE FRONTAL SYSTEM. VERTICAL WIND SHEAR IS
EXPECTED TO INCREASE FURTHER BY THE 24 HOUR POSITION AND WILL
START A SLOW WEAKENING TREND THROUGH THE REMAINDER OF THE
FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 281200Z IS 13
FEET. NEXT WARNINGS AT 290300Z4 (DTG 290151Z8) AND 291500Z7 (DTG
291351Z1).//
=========================================================================
WTPS32 PGTW 980329 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 026
01 ACTIVE TROPICAL CYCLONE IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
290000Z1 --- 16.1S8 155.0E1
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
REPEAT POSIT: 16.1S8 155.0E1
---
FORECASTS:
12 HRS, VALID AT:
291200Z4 --- 16.1S8 153.2E1
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 265 DEG/ 08 KTS
---
24 HRS, VALID AT:
300000Z3 --- 16.2S9 151.6E3
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 260 DEG/ 07 KTS
---
36 HRS, VALID AT:
301200Z6 --- 16.4S1 150.2E8
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 48 HR POSIT: 255 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
310000Z4 --- 16.7S4 148.9E2
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
---
REMARKS:
290300Z4 POSITION 16.1S8 154.5E5.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED WESTWARD AT 12 KNOTS
OVER THE PAST 12 HOURS. THE WARNING POSITION IS BASED ON
282331Z9 VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS
BASED ON A 282331Z9 SATELLITE DVORAK INTENSITY ESTIMATE OF 40
KNOTS. VERTICAL WIND SHEAR AFFECTING THE SYSTEM HAS WEAKENED
SLIGHTLY ALLOWING MORE CONVECTIVE ACTIVITY TO DEVELOP IN THE
NORTHEAST QUADRANT OF THE SYSTEM. THE SYSTEM HAS BEEN UNDER
THE INFLUENCE OF A STRONG RIDGE OF HIGH PRESSURE TO THE SOUTH.
THE RIDGE IS EXPECTED TO CONTINUE STEERING THE SYSTEM. AFTER
THE 36 HOUR PERIOD, TROPICAL CYCLONE 30P (NATHAN) IS EXPECTED
TO SLOW DUE TO A WEAKENING IN THE LOW-LEVEL STEERING FLOW.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290000Z1 IS 13 FEET. NEXT
WARNINGS AT 291500Z7 (DTG 291351Z1) AND 300300Z6 (DTG
300151Z0).//
=========================================================================
WTPS32 PGTW 980329 09:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 027
01 ACTIVE TROPICAL CYCLONE IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
290600Z7 --- 15.9S5 154.1E1
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
REPEAT POSIT: 15.9S5 154.1E1
---
FORECASTS:
12 HRS, VALID AT:
291800Z0 --- 15.9S5 152.2E0
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 260 DEG/ 07 KTS
---
24 HRS, VALID AT:
300600Z9 --- 16.1S8 150.7E3
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 255 DEG/ 06 KTS
---
36 HRS, VALID AT:
301800Z2 --- 16.4S1 149.5E9
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 48 HR POSIT: 240 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
310600Z0 --- 16.9S6 148.5E8
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 72 HR POSIT: 245 DEG/ 05 KTS
---
72 HRS, VALID AT:
010600Z7 --- 17.8S6 146.5E6
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
290900Z0 POSITION 15.9S5 153.6E5.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED WESTWARD AT 10 KNOTS
FOR THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 290530Z9
VISIBLE SATELLITE IMAGERY. THE WARNING POSITION IS BASED ON A
290530Z9 SATELLITE DVORAK INTENSITY ESTIMATE OF 40 KNOTS.
TROPICAL CYCLONE 30P (NATHAN) HAS BEEN UNDER THE INFLUENCE OF A
STRONG RIDGE OF HIGH PRESSURE FOR THE PAST 24 HOURS. THE SYSTEM
CONTINUED TO MAINTAIN ITS INTENSITY AS IT PASSED THROUGH AN AREA
OF MODERATE VERTICAL WIND SHEAR DESPITE ITS SMALL SIZE AND
MINIMAL AMOUNT OF CENTRAL CONVECTION. NUMERICAL GUIDANCE FROM THE
NAVY INDICATES THE SYSTEM WILL CONTINUE ON A WESTERLY TRACK AND
SLOWLY WEAKEN THROUGHOUT THE FORECAST PERIOD. HOWEVER, THE
GEOPHYSICAL FLUID DYNAMIC NAVY MODEL SUGGESTS THE SYSTEM WILL
INTENSIFY AND TRACK SOUTHWARD. THE LATER SCENARIO DOES
NOT CONCUR WITH THE CURRENT SYNOPTIC SITUATION. THEREFORE, THE
FORECAST TRACK SHOWS A WESTWARD MOTION THROUGHOUT THE FORECAST
PERIOD. THIS IS EXPECTED AS THE RIDGE TO THE SOUTH REMAINS THE
PREDOMINANT STEERING MECHANISM. THE SYSTEM IS EXPECTED TO
MAINTAIN ITS INTENSITY THROUGH THE 24 HOUR PERIOD AND WEAKEN
SLOWLY AFTERWARDS DUE TO INCREASED VERTICAL WIND SHEAR AND
INTERACTION WITH LAND. TROPICAL CYCLONE 30P (NATHAN) IS FORECAST
TO DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE BY THE 72 HOUR
PERIOD. SUBSEQUENT WARNINGS WILL BE ISSUED AT SIX-HOUR INTERVALS
UNTIL FURTHER NOTICE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290600Z7
IS 13 FEET. NEXT WARNINGS AT 291500Z7 (DTG 291351Z1), 292100Z4
(DTG 291951Z7), 290300Z4 (DTG 290151Z8) AND 300900Z2 (DTG
300751Z6).//
=========================================================================
WTPS32 PGTW 980329 15:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 028
01 ACTIVE TROPICAL CYCLONE IN THE SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
291200Z4 --- 15.4S0 152.9E7
MOVEMENT PAST SIX HOURS - 285 DEGREES AT 11 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
REPEAT POSIT: 15.4S0 152.9E7
---
FORECASTS:
12 HRS, VALID AT:
300000Z3 --- 15.2S8 150.7E3
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTH SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 24 HR POSIT: 255 DEG/ 09 KTS
---
24 HRS, VALID AT:
301200Z6 --- 15.6S2 148.8E1
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
RADIUS OF 035 KT WINDS - 070 NM SOUTHEAST SEMICIRCLE
060 NM ELSEWHERE
VECTOR TO 36 HR POSIT: 245 DEG/ 08 KTS
---
36 HRS, VALID AT:
310000Z4 --- 16.2S9 147.3E5
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 48 HR POSIT: 250 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
311200Z7 --- 16.6S3 146.2E3
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 72 HR POSIT: 260 DEG/ 04 KTS
---
72 HRS, VALID AT:
011200Z4 --- 16.9S6 144.4E3
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
291500Z7 POSITION 15.4S0 152.4E2.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED WEST-NORTHWESTWARD
AT 11 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS
BASED UPON 291130Z6 ENHANCED INFRARED SATELLITE IMAGERY AND
290902Z2 MICROWAVE IMAGERY. ANIMATED INFRARED SATELLITE IMAGERY
INDICATES THAT CONVECTION CONTINUES TO FLARE UP AND DIE DOWN
ACROSS THE SYSTEM=S CENTER. WATER VAPOR IMAGERY INDICATES A SMALL
UPPER LEVEL LOW NORTHWEST OF TROPICAL CYCLONE 30P (NATHAN) WHICH
IS DISRUPTING THE UPPER LEVEL OUTFLOW. THIS ATMOSPHERIC FEATURE
IS KEEPING THE SYSTEM FROM INTENSIFYING ANY FURTHER. THE WARNING
INTENSITY IS BASED ON CONTINUITY WITH THE PREVIOUS WARNING.
TROPICAL CYCLONE 30P (NATHAN) SHOULD CONTINUE WEST-NORTHWESTWARD
OVER THE NEXT FEW HOURS BUT BEGIN TO TURN MORE WESTWARD BY THE
TWELVE HOUR POSITION. THIS WEST-NORTHWESTWARD MOTION REPRESENTS A
CHANGE FROM THE PREVIOUS FORECAST. THIS IS DUE TO THE ORIENTATION
OF THE HIGH PRESSURE RIDGE IN THE LOWER AND MIDDLE LEVELS OF THE
ATMOSPHERE SOUTH OF THE SYSTEM. BY THE 24 HOUR POSITION THE
SYSTEM SHOULD TURN WEST-SOUTHWESTWARD AS A WEAKNESS DEVELOPS IN
THE LOWER AND MID LEVEL RIDGING DUE TO AN APPROACHING MID-
LATITUDE TROUGH. THIS SHOULD ALSO CAUSE THE SYSTEM TO SLOW IN
FORWARD SPEED. THIS MOTION SHOULD CONTINUE THROUGH 48 HOURS, BUT
WILL SHIFT TO A MORE WESTWARD TRACK BY 72 HOURS AS LOW LEVEL HIGH
PRESSURE BUILDS IN BEHIND THE PASSING SURFACE FRONT. THE SYSTEM
SHOULD HOLD NEAR ITS CURRENT INTENSITY THROUGH THE 24 HOUR
POSITION AS LIGHT TO MODERATE VERTICAL WIND SHEAR AND MID LEVEL
DRY AIR SHOULD PREVENT ANY FURTHER DEVELOPMENT. BY THE 36 HOUR
POSITION AND THROUGH THE REMAINDER OF THE FORECAST VERTICAL WIND
SHEAR WILL INCREASE CAUSING THE CYCLONE TO WEAKEN. LAND
INTERACTION BETWEEN THE 48 AND 72 HOUR POSITION WILL FURTHER
WEAKEN THE SYSTEM. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 291200Z IS
13 FEET. NEXT WARNINGS AT 300300Z6 (DTG 300151Z0) AND 301500Z9
(DTG 301351Z3).//
=========================================================================
WTPS32 PGTW 980329 21:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 029
01 ACTIVE TROPICAL CYCLONE IN THE SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
291800Z0 --- 15.0S6 151.9E6
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
REPEAT POSIT: 15.0S6 151.9E6
---
FORECASTS:
12 HRS, VALID AT:
300600Z9 --- 14.9S4 150.1E7
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 24 HR POSIT: 265 DEG/ 07 KTS
---
24 HRS, VALID AT:
301800Z2 --- 15.0S6 148.7E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 36 HR POSIT: 250 DEG/ 07 KTS
---
36 HRS, VALID AT:
310600Z0 --- 15.4S0 147.4E6
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 48 HR POSIT: 245 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
311800Z3 --- 15.8S4 146.5E6
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 72 HR POSIT: 260 DEG/ 04 KTS
---
72 HRS, VALID AT:
011800Z0 --- 16.1S8 144.7E6
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
292100Z4 POSITION 15.0S6 151.5E2.
TROPICAL CYCLONE 30P (NATHAN) HAS SLOWED SLIGHTLY AS IT TRACKS
WESTWARD AT 10 KNOTS. THE WARNING POSITION IS BASED UPON 301732Z6
ENHANCED INFRARED SATELLITE IMAGERY AND CONTINUITY FROM A
291253Z2 SCATTEROMETER PASS. THE WARNING INTENSITY IS BASED UPON
THE PRESENCE OF 30 KNOT WINDS AND POSSIBLY A SMALL AREA OF 35
KNOT WINDS ASSOCIATED WITH THE LOW LEVEL CIRCULATION CENTER AS
INDICATED BY THE AFOREMENTIONED SCATTEROMETER PASS. THERE IS
NO SIGNIFICANT CHANGE TO THE FORECAST TRACK PHILOSOPHY. RECENT
ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT CONVECTION HAS
RE-DEVELOPED ACROSS THE SYSTEM BUT THIS IS BELIEVED TO BE
TEMPORARY. THE PRESENCE OF A SMALL UPPER LEVEL LOW TO THE NORTH-
NORTHWEST OF THE SYSTEM AS WELL AS LIGHT TO MODERATE VERTICAL
WIND SHEAR SHOULD INHIBIT FURTHER DEVELOPMENT OF THIS SYSTEM.
VERTICAL WIND SHEAR SHOULD INCREASE EVEN MORE BY THE 48 HOUR
POSITION WITH THE SYSTEM BEGINNING TO DISSIPATE OVER THE OPEN
WATER. THE SYSTEM WILL CONTINUE TO DISSIPATE AS IT INTERACTS
WITH LAND BETWEEN THE 48 AND 72 HOUR POSITION. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 301800Z IS 12 FEET. NEXT WARNINGS AT
300900Z2 (DTG 300751Z6) AND 302100Z6 (DTG 301951Z9).//
=========================================================================
WTPS32 PGTW 980330 03:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 030
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
300000Z3 --- 15.1S7 151.4E1
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 06 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
REPEAT POSIT: 15.1S7 151.4E1
---
FORECASTS:
12 HRS, VALID AT:
301200Z6 --- 15.0S6 150.4E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 24 HR POSIT: 270 DEG/ 04 KTS
---
24 HRS, VALID AT:
310000Z4 --- 15.0S6 149.5E9
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 36 HR POSIT: 265 DEG/ 04 KTS
---
36 HRS, VALID AT:
311200Z7 --- 15.1S7 148.7E0
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 48 HR POSIT: 265 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
010000Z1 --- 15.2S8 147.9E1
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 72 HR POSIT: 255 DEG/ 03 KTS
---
72 HRS, VALID AT:
020000Z2 --- 15.5S1 146.5E6
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
300300Z6 POSITION 15.1S7 151.1E8.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED TOWARDS THE WEST
AT 06 KNOTS FOR THE PAST 12 HOURS. THE WARNING POSITION IS
BASED ON 292330Z9 VISIBLE SATELLITE IMAGERY. THE WARNING
INTENSITY IS BASED ON CONTINUITY FROM A 291254Z3 SCATTEROMETER
PASS. THE RIDGE OF HIGH PRESSURE TO THE SOUTH CONTINUES TO
FORCE THE SYSTEM WESTWARD. TROPICAL CYCLONE 30P (NATHAN) IS
EXPERIENCING AN INCREASE IN VERTICAL WIND SHEAR, THUS
ARRESTING FURTHER DEVELOPMENT. THE SYSTEM IS EXPECTED TO
BEGIN DISSIPATING BY THE END OF THE FORECAST PERIOD. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 300000Z3 IS 13 FEET. NEXT WARNINGS
AT 300900Z2 (DTG 300751Z6), 301500Z9 (DTG 301351Z3), 302100Z6
(DTG 301951Z9) AND 310300Z7 (DTG 310151Z1). REFER TO TROPICAL
CYCLONE 31P WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY
UPDATES.//
=========================================================================
WTPS32 PGTW 980330 09:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 031
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
300600Z9 --- 15.1S7 150.1E7
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
REPEAT POSIT: 15.1S7 150.1E7
---
FORECASTS:
12 HRS, VALID AT:
301800Z2 --- 15.1S7 148.6E9
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 24 HR POSIT: 255 DEG/ 07 KTS
---
24 HRS, VALID AT:
310600Z0 --- 15.4S0 147.2E4
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
VECTOR TO 36 HR POSIT: 260 DEG/ 05 KTS
---
36 HRS, VALID AT:
311800Z3 --- 15.6S2 146.1E2
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 48 HR POSIT: 255 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
010600Z7 --- 15.8S4 145.3E3
MAX SUSTAINED WINDS - 025 KT, GUSTS 030 KT
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
300900Z2 POSITION 15.1S7 149.7E1.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED WESTWARD AT 10 KNOTS
FOR THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON
300530Z1 VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS
BASED ON A 300000Z3 SYNOPTIC REPORT FROM WILLIS ISLAND (WMO 94299)
INDICATING SUSTAINED EASTERLY WINDS OF 30 KNOTS. A STRONG
HIGH PRESSURE RIDGE IS EXPECTED TO CONTINUE STEERING THE
SYSTEM TOWARD THE WEST FOR THE ENTIRE FORECAST PERIOD. THE
SYSTEM IS FORECAST TO SLOW BY THE END OF THE 36 HOUR PERIOD
DUE TO A WEAKENING IN THE RIDGE. THE SYSTEM IS FORECAST TO
MAKE LAND FALL AND DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE
BY THE 48 PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
300600Z9 IS 13 FEET. NEXT WARNINGS AT 301500Z9 (DTG
301351Z3), 302100Z6 (DTG 301951Z9), 310300Z7 (DTG 310151Z1),
AND 310900Z3 (DTG 310751Z7). REFER TO TROPICAL CYCLONE 31P
WARNINGS (WTPS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980330 21:00z
IMMEDIATE DELIVERY REQ TO AMEMBASSY SUVA
AMEMBASSY SUVA REQ PASS TO USAID OFDA ADVISOR
IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT MORESBY
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 033
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
301800Z2 --- 14.8S3 147.3E5
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 14 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION
OF SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
REPEAT POSIT: 14.8S3 147.3E5
---
FORECASTS:
12 HRS, VALID AT:
310600Z0 --- 14.7S2 145.3E3
MAX SUSTAINED WINDS - 035 KT, GUSTS 040 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 260 DEG/ 08 KTS
---
24 HRS, VALID AT:
311800Z3 --- 14.9S4 143.7E5
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
302100Z6 POSITION 14.8S3 146.8E9.
TROPICAL CYCLONE 30P (NATHAN) HAS TRACKED WESTWARD AT 14
KNOTS THE PAST 06 HOURS. THE SYSTEM HAS BEEN DIFFICULT
TO POSITION DUE TO THE DISORGANIZED CLOUD STRUCTURE EVIDENT
IN INFRARED SATELLITE IMAGERY. THE WARNING POSITION IS BASED UPON
301730Z4 ENHANCED INFRARED SATELLITE IMAGERY AND OBSERVATIONS
FROM WMO NUMBERS 94299, 94289 AND 95288. THE SYSTEMS CONVECTION
HAS CONTINUED TO DECREASE AS INDICATED BY ANIMATED INFRARED
SATELLITE IMAGERY. THE WARNING POSITION IS BASED IN PART ON
OBSERVATIONS FROM WMO NUMBER 95288 AND CONTINUITY FROM THE
PREVIOUS WARNING. THE SYSTEM SHOULD CONTINUE TO WEAKEN AS IT
IS STEERED BY LOW LEVEL EASTERLY FLOW AND SHOULD BE OVER LAND
BETWEEN THE 12 AND 24 HOUR POSITION. THE SYSTEM SHOULD DISSIPATE
OVER AUSTRALIA BY THE 24 HOUR POSITION. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 301800Z IS 12 FEET. NEXT WARNINGS AT 310900Z3 (DTG 310751Z7
).
REFER TO TROPICAL CYCLONE 31P (ZUMAN) WARNINGS (WTPS31 PGTW) FOR
TWELVE-HOURLY UPDATES.//
=========================================================================
WTPS32 PGTW 980331 03:00z
1. TROPICAL CYCLONE 30P (NATHAN) WARNING NR 034 RELOCATED
02 ACTIVE TROPICAL CYCLONES IN SOUTHWEST PACIFIC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
310000Z4 --- 13.5S9 144.9E8
MOVEMENT PAST SIX HOURS - 295 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 035 KT
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 13.5S9 144.9E8
---
FORECASTS:
12 HRS, VALID AT:
311200Z7 --- 12.9S2 142.9E6
MAX SUSTAINED WINDS - 020 KT, GUSTS 025 KT
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
310300Z7 POSITION 13.3S7 144.4E3.
TROPICAL CYCLONE 30P (NATHAN) WAS RELOCATED DUE TO THE DIFFICULT
OF INFRARED SATELLITE IMAGERY TO IDENTIFY THE LOW-LEVEL CLOUD
FEATURES AND THE RAPID DISSIPATION OF THE SYSTEM. THE WARNING
POSITION AND INTENSITY ARE BASED ON A 302330Z1 VISIBLE SATELLITE
IMAGERY. EXPECTING TC 30P (NATHAN) TO CONTINUE ON ITS PRESENT
TRACK AND MAKE LANDFALL AND DISSIPATE OVER AUSTRALIA. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 310000Z IS 12 FEET. THIS IS THE FINAL
WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER
(NAVPACMETOCCEN WEST GU). THE SYSTEM WILL BE CLOSELY MONITORED
FOR SIGNS OF REGENERATION. REFER TO TROPICAL CYCLONE 31P (ZUMAN)
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
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Document: tropical_cyclone_nathan_jtwc_advisories.htm
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