Updated: 17 June 2020
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[Index] | Tropical Cyclone ASMA : JTWC Advisories |
| Season 2008-2009 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
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WTXS21 PGTW 20081016 16:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 5.7S 69.7E TO 7.7S 66.1E WITHIN
THE NEXT 06 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE
OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE
AREA ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT IMAGERY AT
161530Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 5.8S
69.0E. THE SYSTEM IS MOVING WESTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 5.6S
70.2E IS NOW LOCATED NEAR 5.8S 68.7E, APPROXIMATELY 225 NM WEST-
NORTHWEST OF DIEGO GARCIA. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS IMPROVED ORGANIZATION OVER THE PAST 12 HOURS WITH
CONVECTION BECOMING LESS SHEARED AND STARTING TO WRAP INTO
THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 161400Z SSMI IMAGE
SHOWS A WELL DEFINED LLCC WITH IMPROVED AND MORE INTENSE
CONVECTIVE BANDING. A 160421Z ASCAT PASS INDICATED 25-30 KNOT
UNFLAGGED WINDS NEAR THE CENTER AND A TIGHTLY-WRAPPED LLCC.
THE LLCC REMAINS UNDER THE NORTHWESTERN PERIPHERY OF AN UPPER
LEVEL ANTICYCLONE, BUT HAS TRACKED WEST-SOUTHWESTWARD INTO A MORE
FAVORABLE ENVIRONMENT WITH A SLIGHT DECREASE IN VERTICAL WIND SHEAR
(20-30 KNOTS). OVERALL, THE ENVIRONMENT IS FAVORABLE FOR FURTHER
DEVELOPMENT WITH GOOD OUTFLOW AND WARM SST. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED
BY 171630Z.//
=========================================================================
WTXS31 PGTW 20081016 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/161621Z OCT 08//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
161800Z --- NEAR 5.5S 68.4E
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 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 5.5S 68.4E
---
FORECASTS:
12 HRS, VALID AT:
170600Z --- 5.7S 67.7E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 240 DEG/ 04 KTS
---
24 HRS, VALID AT:
171800Z --- 6.1S 67.0E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 235 DEG/ 05 KTS
---
36 HRS, VALID AT:
180600Z --- 6.7S 66.1E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 230 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
181800Z --- 7.4S 65.3E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
---
REMARKS:
162100Z POSITION NEAR 5.5S 68.2E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 270 NM WEST-
NORTHWEST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 06 KNOTS OVER THE
PAST SIX HOURS. RECENT ANIMATED METSAT IMAGERY INDICATES AN ORANIZED
LOW LEVEL CIRCULATION CENTER (LLCC) WITH CONVECTION STARTING TO WRAP
INTO THE LLCC. EARLIER SCATTEROMETER DATA SUPPORTED A 30-35 KNOT
SYSTEM AND RECENT DVORAK INTENSITY ESTIMATES HAVE INCREASED TO 35
KNOTS. THE UPPER LEVEL ENVIRONMENT IS PROVIDING GOOD DIFFLUENCE BUT
MODERATE NORTHEASTERLY VERTICAL WIND SHEAR OF 20-30 KNOTS, WHICH
SHOULD LEAD TO SLOW INTENSIFICATION THROUGH TAU 24. THE SYSTEM
IS UNDER WEAK COMPETING STEERING ENVIRONMENTS WITH WESTWARD
STEERING FROM THE SUBTROPICAL RIDGE (STR) TO THE SOUTH AND
EASTWARD STEERING FROM STRONG, LOW LEVEL EQUATORIAL WESTERLIES.
THEREFORE, TC 01S IS EXPECTED TO MOVE SLOWLY WEST-SOUTHWESTWARD TO
SOUTHWESTWARD INTO AN AREA OF REDUCED VERTICAL WIND SHEAR AND
SHOULD INTENSIFY IN THE MORE FAVORABLE ENVIRONMENT AFTER TAU 24.
THE COMPETING STEERING FLOWS HAVE LED TO POOR MODEL AGREEMENT ON
BOTH THE TRACK AND INTENSITY FORECASTS WITH TWO GROUPINGS. THIS
FORECAST FAVORS THE GENERALLY WEST-SOUTHWESTWARD TRACK AND A
STRONGER SYSTEM. A NUMBER OF MODELS INDICATE AN EASTWARD TRACK
WITH A WEAK SYSTEM STEERING UNDER THE EQUATORIAL WESTERLIES (GFDN,
EGRR, NOGAPS). THIS WARNING SUPERSEDES AND CANCELS REF A,
NAVMARFCSTCEN 161621Z OCT 08 TROPICAL CYCLONE FORMATION
ALERT (WTXS21 PGTW 161630). MAXIMUM SIGNIFICANT WAVE HEIGHT AT
161800Z IS 10 FEET. NEXT WARNINGS AT 170900Z AND 172100Z.//
=========================================================================
WTXS31 PGTW 20081017 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
170600Z --- NEAR 5.9S 68.1E
MOVEMENT PAST SIX HOURS - 235 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 5.9S 68.1E
---
FORECASTS:
12 HRS, VALID AT:
171800Z --- 6.5S 67.6E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 220 DEG/ 04 KTS
---
24 HRS, VALID AT:
180600Z --- 7.1S 67.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 230 DEG/ 05 KTS
---
36 HRS, VALID AT:
181800Z --- 7.7S 66.4E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 240 DEG/ 05 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
190600Z --- 8.2S 65.6E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
---
REMARKS:
170900Z POSITION NEAR 6.0S 68.0E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 275 NM WEST-
NORTHWEST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 04 KNOTS OVER
THE PAST SIX HOURS. RECENT ANIMATED METSAT IMAGERY INDICATES THE LOW
LEVEL CIRCULATION CENTER (LLCC) HAS STARTED TO BECOME MORE CONCENTRIC
WITH PERSISTENT CONVECTION ON THE SOUTHERN AND SOUTHWESTERN PERIPHERY
OF THE LLCC. DVORAK INTENSITY ESTIMATES HAVE REMAINED CONSISTENT AT
35 KNOTS. RECENT QUIKSCAT IMAGERY MISSED THE SYSTEM BUT INDICATES
20-25 KNOT WINDS ON THE BOUNDARY OF THE LLCC. THE UPPER LEVEL EN-
VIRONMENT CONTINUES TO PROVIDE GOOD DIFFLUENCE BUT THE SYSTEM REMAINS
IN A REGION OF MODERATE TO HIGH NORTHEASTERLY VERTICAL WIND SHEAR
WITH VALUES OF 20-30 KNOTS. THE VERTICAL WIND SHEAR IS CONTRIBUTING
TO THE LACK OF CONVECTION OVER THE NORTHERN PERIPHERY OF THE LLCC.
VERTICAL WIND SHEAR WILL ALSO BE THE PRIMARY FACTOR IN LIMITING
THE SYSTEM TO ONLY SLOW INTENSIFICATION THROUGHOUT THE FORECAST
PERIOD. THE SYSTEM REMAINS IN A WEAK COMPETING STEERING ENVIRONMENT
WITH WESTWARD STEERING FROM THE SUBTROPICAL RIDGE (STR) TO THE SOUTH
AND EASTWARD STEERING FROM STRONG, LOW LEVEL EQUATORIAL WESTERLIES.
THEREFORE, TC 01S IS EXPECTED TO MOVE SLOWLY WEST-SOUTHWESTWARD TO
SOUTHWESTWARD INTO AN AREA OF REDUCED VERTICAL WIND SHEAR AND SHOULD
INTENSIFY SLOWLY THROUGH TAU 48. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
170600Z IS 11 FEET. NEXT WARNINGS AT 172100Z AND 180900Z.//
=========================================================================
WTXS31 PGTW 20081017 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
171800Z --- NEAR 7.2S 68.2E
MOVEMENT PAST SIX HOURS - 190 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 7.2S 68.2E
---
FORECASTS:
12 HRS, VALID AT:
180600Z --- 8.3S 67.9E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 210 DEG/ 05 KTS
---
24 HRS, VALID AT:
181800Z --- 9.2S 67.4E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 220 DEG/ 06 KTS
---
36 HRS, VALID AT:
190600Z --- 10.2S 66.6E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 235 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
191800Z --- 10.9S 65.6E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
---
REMARKS:
172100Z POSITION NEAR 7.5S 68.1E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 255 NM WEST OF
DIEGO GARCIA, HAS TRACKED SOUTHWARD AT 05 KNOTS OVER THE PAST SIX
HOURS. RECENT ANIMATED METSAT IMAGERY INDICATES THE LOW LEVEL CIRC-
ULATION CENTER (LLCC) REMAINS PARTIALLY EXPOSED FROM THE CONVECTION
THAT CONTINUES TO FLARE ON THE SOUTHWESTERN PERIPHERY OF THE SYSTEM.
A 171330Z QUIKSCAT PASS INDICATES A WELL DEFINED LLCC WITH 30 TO 35
KNOTS OF WIND ON THE NORTHWESTERN PORTION OF THE SYSTEM. THE SOUTH-
WESTERN QUADRANT HAS SIGNIFICANT RAIN FLAGGED WINDS, BUT IS CONSIST-
ENT WITH ANIMATED IMAGERY SHOWING SOUTHWESTERLY SHEARING OF THE CON-
VECTION. THE UPPER LEVEL ENVIRONMENT REMAINS DIVIDED BY GOOD OUTFLOW
ON THE POLEWARD SIDE OF THE SYSTEM AND MODERATE TO HIGH VERTICAL WIND
SHEAR WITH VALUES OF 20-30 KNOTS LIMITING THE SYSTEM TO SLOW DEVELOP-
MENT AS IT TRACKS TOWARDS A REGION OF LOWER VERTICAL WIND SHEAR.
STEERING REMAINS WEAKLY INFLUENCED BY WESTERLY FLOW EQUATORWARD OF
SYSTEM AND A DEVELOPING SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST.
THE TRACK IS CONSISTENT WITH MODEL GUIDANCE SHOWING THE STR STRENG-
THENING AND CAUSING THE MORE WESTWARD TURN BETWEEN TAU 36 AND 48.
INTENSITY WILL REMAIN STIFFLED BY THE HIGH LEVELS OF VERTICAL WIND
SHEAR THOUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 171800Z IS 12 FEET. NEXT WARNINGS AT 180900Z AND 182100Z.
=========================================================================
WTXS31 PGTW 20081018 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
180600Z --- NEAR 8.3S 67.7E
MOVEMENT PAST SIX HOURS - 215 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 8.3S 67.7E
---
FORECASTS:
12 HRS, VALID AT:
181800Z --- 9.4S 66.9E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 230 DEG/ 08 KTS
---
24 HRS, VALID AT:
190600Z --- 10.5S 65.6E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 240 DEG/ 08 KTS
---
36 HRS, VALID AT:
191800Z --- 11.3S 64.1E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 255 DEG/ 09 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
200600Z --- 11.7S 62.4E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
---
REMARKS:
180900Z POSITION NEAR 8.6S 67.5E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 290 NM WEST-
SOUTHWEST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. RECENT MULTISPECTRAL AND MICROWAVE SATELLITE
DATA SUGGEST THAT TC 01S HAS BEGUN TO TURN SLOWLY WESTWARD OVER THE
PAST 06 HOURS UNDER THE STEERING INFLUENCE OF A LOW TO MID-LEVEL
STEERING RIDGE TO THE SOUTH AND EAST OF THE LOW LEVEL CIRCULATION
CENTER (LLCC). STRONG EAST-NORTHEASTERLY UPPER-LEVEL WINDS CONTINUE
TO SHEAR THE DEEPEST CONVECTION ASSOCIATED WITH THIS SYSTEM TO THE
WEST AND SOUTH OF THE LLCC. HOWEVER, STRONG DIFFLUENCE IN THE UPPER
LEVEL FLOW IS ENABLING THE CYCLONE TO MAINTAIN INTENSITY DESPITE
HIGH VERTICAL WIND SHEAR. TC 01S IS EXPECTED TO CONTINUE TURNING
WESTWARD OVER THE NEXT 48 HOURS AS THE CURRENT SUBTROPICAL STEERING
RIDGE BUILDS ALONG THE POLEWARD SIDE OF THE CYCLONE. FOLLOWING THIS
TRACK, THE CYCLONE WILL ENTER AN AREA OF LOWER, BUT STILL MODERATE,
VERTICAL WIND SHEAR NEAR THE UPPER LEVEL RIDGE AXIS. THIS ANTICIPATED
DECREASE IN SHEAR SHOULD ALLOW SLOW INTENSIFICATION AFTER TAU 12.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 180600Z IS 14 FEET. NEXT WARNINGS
AT 182100Z AND 190900Z.//
=========================================================================
WTXS31 PGTW 20081018 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
181800Z --- NEAR 8.8S 67.2E
MOVEMENT PAST SIX HOURS - 225 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 8.8S 67.2E
---
FORECASTS:
12 HRS, VALID AT:
190600Z --- 9.9S 66.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 235 DEG/ 09 KTS
---
24 HRS, VALID AT:
191800Z --- 10.9S 64.4E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 250 DEG/ 08 KTS
---
36 HRS, VALID AT:
200600Z --- 11.5S 62.8E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 270 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
201800Z --- 11.5S 60.7E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
---
REMARKS:
182100Z POSITION NEAR 9.1S 66.9E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 325 NM WEST-
SOUTHWEST OF DIEGO GARCIA, HAS TRACKED SOUTHWESTWARD AT 03 KNOTS
OVER THE PAST SIX HOURS. DEEP CONVECTION HAS CONTINUED TO FLARE
OVER AN OBSCURED LOW LEVEL CIRCULATION CENTER, THOUGH A 181538Z
TRMM MICROWAVE IMAGE HAS INCREASED POSITION CERTAINTY. CURRENT
INTENSITY IS BASED ON SATELLITE INTENSITY ESTIMATES FROM PGTW
FMEE AND KNES RANGING FROM 25 TO 35 KNOTS. VERTICAL WIND
SHEAR CONTINUES TO LIMIT SHORT TERM INTENSIFICATION. HOWEVER,
POLEWARD OUTFLOW HAS MARGINALLY IMPROVED WITH THE PASSAGE OF
A LONGWAVE TROUGH. THE SYSTEM IS FORECAST TO TRACK GENERALLY
SOUTHWESTWARD DURING THE NEXT 24 HOURS UNDER THE STEERING
INFLUENCE OF THE LOW LEVEL EASTERLY FLOW. AS THE SYSTEM
INTENSIFIES THROUGHOUT THE FORECAST PERIOD THE SYSTEM WILL BEGIN
TO REACT TO THE STEERING EFFECTS OF THE 700 MB LEVEL. THE 700
MB STR WILL BEGIN TO BUILD TO THE SOUTHEAST OF THE SYSTEM
INITIALLY, THEN ORIENT ITSELF ZONALLY TO THE SOUTH, CONTRIBUTING
TO A MORE WESTWARD TRACK BEYOND TAU 24. THEREAFTER, THE RIDGE IS
EXPECTED TO STRENGTHEN TO THE SOUTH OF THE SYSTEM ACCOUNTING
FOR INCREASED FORECAST SPEEDS BEYOND TAU 36. THE INTENSITY
FORECAST REMAINS MUCH THE SAME AS THE PREVIOUS FORECAST.
VERTICAL WIND SHEAR IS EXPECTED TO GRADUALLY ABATE AS THE SYSTEM
APPROACHES THE UPPER LEVEL STR AXIS TO THE SOUTH. HOWEVER, LOW
OCEAN HEAT CONTENT AND CONTINUED LOW TO MODERATE VERTICAL WIND
SHEAR WILL HINDER SIGNIFICANT INTENSITY GAINS THROUGHOUT THE
FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 181800Z
IS 17 FEET. NEXT WARNINGS AT 190900Z AND 192100Z.//
=========================================================================
WTXS31 PGTW 20081019 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 006
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
190600Z --- NEAR 10.3S 64.7E
MOVEMENT PAST SIX HOURS - 245 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 10.3S 64.7E
---
FORECASTS:
12 HRS, VALID AT:
191800Z --- 11.3S 63.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 250 DEG/ 08 KTS
---
24 HRS, VALID AT:
200600Z --- 11.9S 61.4E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 260 DEG/ 09 KTS
---
36 HRS, VALID AT:
201800Z --- 12.2S 59.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 270 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
210600Z --- 12.2S 57.5E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
---
REMARKS:
190900Z POSITION NEAR 10.6S 64.3E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 840 NM NORTH-
EAST OF LA REUNION, HAS TRACKED WEST-SOUTHWESTWARD AT 13 KNOTS OVER
THE PAST SIX HOURS. TC 01S CONTINUES TO TRACK INCREASINGLY WESTWARD
UNDER THE STEERING INFLUENCE OF A ZONALLY-ORIENTED SUBTROPICAL
RIDGE TO THE SOUTH. THE CURRENT POSITION IS BASED ON RECENT MICRO-
WAVE IMAGERY, INCLUDING A 190216Z SSMI PASS, AND A 180600Z PGTW
SATELLITE FIX. THE INTENSITY ESTIMATE OF 35 KNOTS IS CONSISTENT
WITH DVORAK T-NUMBERS REPORTED BY PGTW, KNES, AND FMEE. TS 01S
WILL CONTINUE TO TRACK GENERALLY WEST-SOUTHWESTWARD THROUGH THE
FORECAST PERIOD UNDER THE CONTINUED STEERING INFLUENCE OF THE
SUBTROPICAL RIDGE TO THE SOUTH. THIS MOTION WILL TAKE THE SYSTEM
INTO AN AREA OF DECREASING VERTICAL WIND SHEAR NEAR THE AXIS OF AN
UPPER-LEVEL RIDGE. THE DECREASE IN SHEAR AND GOOD OUTFLOW ALOFT
SHOULD ALLOW THE CYCLONE TO INTENSIFY AFTER TAU 12, BUT PASSAGE
OVER DECREASING OCEAN HEAT CONTENT AND AT LEAST SOME CONTINUED
EASTERLY SHEAR WILL PREVENT THE SYSTEM FROM INTENSIFYING RAPIDLY.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 190600Z IS 17 FEET. NEXT
WARNINGS AT 192100Z AND 200900Z.//
=========================================================================
WTXS31 PGTW 20081019 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ONE) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
191800Z --- NEAR 11.2S 63.3E
MOVEMENT PAST SIX HOURS - 240 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 11.2S 63.3E
---
FORECASTS:
12 HRS, VALID AT:
200600Z --- 11.9S 61.5E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 265 DEG/ 09 KTS
---
24 HRS, VALID AT:
201800Z --- 12.1S 59.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 265 DEG/ 11 KTS
---
36 HRS, VALID AT:
210600Z --- 12.2S 57.5E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 270 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
211800Z --- 12.2S 55.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
---
REMARKS:
192100Z POSITION NEAR 11.4S 62.9E.
TROPICAL CYCLONE (TC) 01S (ONE) LOCATED APPROXIMATELY 745 NM NORTH-
EAST OF LA REUNION, HAS TRACKED WEST-SOUTHWESTWARD AT 08 KNOTS OVER
THE PAST SIX HOURS. TC 01S HAS BEGUN TO INTENSIFY IN RESPONSE TO
DECREASED VERTICAL WIND SHEAR AS THE SYSTEM NEARS THE SUBTROPICAL
RIDGE AXIS TO THE SOUTH. DUAL EXHAUST MECHANISMS HAVE ALSO FACILITATED
INTENSIFICATION, THOUGH LOW OCEAN HEAT CONTENT HAS CURTAILED AGGRESSIVE
INTENSIFICATION. CURRENT INTENSITY IS THE AVERAGE OF SATELLITE
INTENSITY ESTIMATES FROM PGTW AND KNES RANGING FROM 35 TO 45 KNOTS.
RECENT METSAT IMAGERY AND A 1514Z SSMIS MICROWAVE IMAGE DEPICT
SPIRAL BANDING, ESPECIALLY WITHIN THE WESTERN SEMICIRCLE. VERTICAL
WIND SHEAR CONTINUES TO DISPLACE THE BULK OF DEEP CONVECTION TO THE
SOUTHWEST OF THE CIRRUS-OBSCURED LOW LEVEL CIRCULATION CENTER. THE
FORECAST TRACK PRESCRIBES AN INCREASED WESTWARD TRACK AND SPEED AS THE
LOW TO MID-LEVEL SUBTROPICAL RIDGE BUILDS TO THE SOUTH OF THE STORM.
THE STORM WILL GRADUALLY INTENSIFY OVER THE NEXT DAY OR SO AS SHEAR
CONTINUES TO RELAX. AGAIN, LOW OCEAN HEAT CONTENT WILL PREVENT
SIGNIFICANT INTENSIFICATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 191800Z
IS 17 FEET. NEXT WARNINGS AT 200900Z AND 202100Z.
=========================================================================
WTXS31 PGTW 20081020 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ASMA) WARNING NR 008
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
200600Z --- NEAR 12.5S 61.7E
MOVEMENT PAST SIX HOURS - 250 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 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.5S 61.7E
---
FORECASTS:
12 HRS, VALID AT:
201800Z --- 12.8S 60.1E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 265 DEG/ 09 KTS
---
24 HRS, VALID AT:
210600Z --- 12.9S 58.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 265 DEG/ 12 KTS
---
36 HRS, VALID AT:
211800Z --- 13.0S 55.8E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 265 DEG/ 13 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
220600Z --- 13.2S 53.1E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
---
REMARKS:
200900Z POSITION NEAR 12.6S 61.3E.
TROPICAL CYCLONE (TC) 01S (ASMA) LOCATED APPROXIMATELY 630 NM NORTH-
EAST OF LA REUNION, HAS TRACKED WEST-SOUTHWESTWARD AT 08 KNOTS OVER
THE PAST SIX HOURS. THE CYCLONE HAS INTENSIFIED OVER THE PAST 12 HOURS
AFTER MOVING INTO A REGION OF DECREASING VERTICAL WIND SHEAR AND FAVOR-
ABLE POLEWARD OUTFLOW NEAR THE AXIS OF AN UPPER LEVEL RIDGE. SEVERAL
RECENT MICROWAVE SATELLITE IMAGES, INCLUDING A 200202Z SSMI PASS,
INDICATE THAT A LOW LEVEL EYE HAS DEVELOPED DESPITE A LOSS OF DEEP
CONVECTION NEAR THE LOW LEVEL CIRCULATION CENTER (LLCC). BASED ON
THE CONSOLIDATED LOW LEVEL STRUCTURE AND DVORAK T-NUMBERS OF 3.5
FROM KNES AND 3.0 FROM BOTH PGTW AND FMEE, THE CURRENT INTENSITY
ESTIMATE IS SET AT 55 KNOTS. TC 01S WILL TRACK GENERALLY WESTWARD
OVER THE NEXT 48 HOURS UNDER THE STEERING INFLUENCE OF LOW TO MID-
LEVEL SUBTROPICAL RIDGING TO THE SOUTH. GOOD OUTFLOW ALOFT SHOULD
ALLOW TC 01S TO INTENSIFY THROUGH THE FORECAST PERIOD, ALTHOUGH
MODERATE VERTICAL WIND SHEAR AND PASSAGE ACROSS COOLER WATER WILL
LIKELY LIMIT THIS INTENSIFICATION TO A SLOW RATE. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 200600Z IS 17 FEET. NEXT WARNINGS
AT 202100Z AND 210900Z.//
=========================================================================
WTXS31 PGTW 20081020 21:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ASMA) WARNING NR 009
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
201800Z --- NEAR 12.3S 61.1E
MOVEMENT PAST SIX HOURS - 260 DEGREES AT 05 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
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.3S 61.1E
---
FORECASTS:
12 HRS, VALID AT:
210600Z --- 12.3S 59.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 260 DEG/ 11 KTS
---
24 HRS, VALID AT:
211800Z --- 12.6S 57.2E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 260 DEG/ 11 KTS
---
36 HRS, VALID AT:
220600Z --- 12.9S 54.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 245 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
221800Z --- 13.7S 52.9E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
---
REMARKS:
202100Z POSITION NEAR 12.3S 60.7E.
TROPICAL CYCLONE (TC) 01S (ASMA) LOCATED APPROXIMATELY 620 NM NORTH-
NORTHEAST OF LA REUNION, HAS TRACKED WESTWARD AT 05 KNOTS OVER
THE PAST SIX HOURS. THE CYCLONE HAS WEAKENED OVER THE PAST 12 HOURS
AS IT HAS TRACKED INTO AN AREA OF MARGINAL SST AND INCREASED VERTICAL
WIND SHEAR. RECENT MICROWAVE SATELLITE IMAGERY INDICATES SIGNIFICANT
DECREASE IN CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER (LLCC).
TC 01S WILL TRACK GENERALLY WESTWARD THROUGH TAU 36 WITH A MORE POLE-
WARD TURN AROUND TAU 48 UNDER THE STEERING INFLUENCE OF LOW TO MID-
LEVEL SUBTROPICAL RIDGING TO THE SOUTH. GOOD OUTFLOW ALOFT SHOULD
ALLOW TC 01S TO MAINTAIN INTENSITY THROUGH23 TAU 36 WITH INCREASED
VERTICAL WIND SHEAR AND DECREASING SST CAUSING A WEAKENING TREND
BEYOND TAU 36. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 201800Z IS 14 FEET.
NEXT WARNINGS AT 210900Z AND 212100Z.
=========================================================================
WTXS31 PGTW 20081021 09:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 01S (ASMA) WARNING NR 010
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
210600Z --- NEAR 12.2S 59.4E
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 045 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 12.2S 59.4E
---
FORECASTS:
12 HRS, VALID AT:
211800Z --- 12.3S 57.2E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
VECTOR TO 24 HR POSIT: 260 DEG/ 11 KTS
---
24 HRS, VALID AT:
220600Z --- 12.6S 54.9E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
210900Z POSITION NEAR 12.2S 58.8E.
TROPICAL CYCLONE (TC) 01S (ASMA) LOCATED APPROXIMATELY 575 NM NORTH-
NORTHEAST OF LA REUNION, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE
PAST SIX HOURS. THE CYCLONE HAS WEAKENED OVER THE PAST 12 HOURS WHILE
TRACKING OVER AN AREA OF MARGINAL SST AND INCREASED VERTICAL WIND
SHEAR. RECENT ANIMATED METSAT IMAGERY AND A 210352 SSMIS IMAGE DEPICT
A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) MOVING WEST OF THE
SIGNIFICANT CONVECTION WHICH IS QUICKLY WANING UNDER THE INFLUENCE OF
STRONG VERTICAL WIND SHEAR. THE CURRENT INTENSITY IS BASED UPON DVORAK
ESTIMATES OF 25 KNOTS FROM FMEE, KNES AND PGTW AND A RECENT QSCAT PASS
SHOWING 30 TO 35 KNOT WINDS NEAR THE LLCC. TC 01S WILL TRACK GENERALLY
WESTWARD THROUGH TAU 24 UNDER THE STEERING INFLUENCE OF LOW TO MID- LEVEL
SUBTROPICAL RIDGING TO THE SOUTH. THE SYSTEM WILL CONTINUE WEAKENING DUE
TO INCREASED VERTICAL WIND SHEAR AND DECREASING SST AND ULTIMATELY DIS-
SIPATE OVER WATER NEAR TAU 24. THIS IS THE FINAL WARNING ON THIS SYSTEM
BY THE JOINT TYPHOON WARNING CENTER (NAVMARFCSTCEN). THE SYSTEM WILL BE
CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 210600Z IS 13 FEET.
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
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Document: tropical_cyclone_asma_jtwc_advisories.htm
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