WTPS21 PGTW 20090404 00:30z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
180 NM EITHER SIDE OF A LINE FROM 18.1S 163.5W TO 23.9S 160.9W
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 IM-
AGERY AT 161230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 18.9S 163.2W.  THE SYSTEM IS MOVING SOUTHWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.2S
57.6E, IS NOW LOCATED NEAR 11.3S 57.0E, APPROXIMATELY 600 NM NORTH
OF LA REUNION. ANIMATED INFRARED SATELLITE IMAGERY SHOWS A RAPIDLY
CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTIVE BANDING WRAPPING INTO THE CENTER. ANIMATED WATER VAPOR
IMAGERY SHOWS A WELL DEVELOPED POLEWARD OUTFLOW CHANNEL ASSOCIATED
WITH AN APPROACHING UPPER LEVEL TROUGH AND A DEVELOPING EQUATORWARD
OUTFLOW CHANNEL. A 031841Z ASCAT PASS SHOWS AN ORGANIZED SURFACE
CIRCULATION. 24 HOUR PRESSURE TRENDS IN THE AREA INDICATE A 2MB
DROP. THE SYSTEM IS IN A FAVORABLE ENVIRONMENT WITH LOW VERTICAL
WIND SHEAR, DIFFLUENCE ALOFT AND HIGH SEA SURFACE TEMPERATURES. THE
SYSTEM IS IN A WEAK STEERING ENVIRONMENT. THE PRIMARY INFLUENCE IS
THE NORTHERN FLANK OF THE SUB-TROPICAL RIDGE TO THE SOUTH SLOWLY
STEERING THE SYSTEM TO THE WEST. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1002 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
050030Z.
=========================================================================
WTPS31 PGTW 20090404 03:00z
1. TROPICAL CYCLONE 25P (LIN) WARNING NR 001
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   040000Z --- NEAR 17.7S 175.7W
     MOVEMENT PAST SIX HOURS - 150 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: 17.7S 175.7W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   041200Z --- 18.9S 174.7W
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 150 DEG/ 09 KTS
    ---
   24 HRS, VALID AT:
   050000Z --- 20.5S 173.8W
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 155 DEG/ 10 KTS
    ---
   36 HRS, VALID AT:
   051200Z --- 22.3S 172.9W
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 155 DEG/ 13 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   060000Z --- 24.7S 171.8W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            035 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
    ---
REMARKS:
040300Z POSITION NEAR 18.0S 175.4W.
TC 25P (LIN), LOCATED APPROXIMATELY 330 NM EAST OF
SUVA, FIJI, HAS MOVED SOUTH-SOUTHEASTWARD AT 13 KNOTS OVER
THE PAST O6 HOURS. THE LOW LEVEL CIRCULATION CENTER (LLCC)
HAS RAPIDLY CONSOLIDATED WHILE DEEP CONVECTION (ENHANCED BY
MAXIMUM DIURNAL COOLING OVERNIGHT) AGGRESSIVELY BUILT IN
OVER THE CENTER. A 031812Z QUIKSCAT IMAGE DEPICTS A STRONG
AND TIGHTENED LLCC WITH WINDS NEAR THE CENTER AS HIGH AS
45 KNOTS; THOUGH MOST OF THESE WIND OBSERVATIONS ARE
SUSPECT DUE TO THE INTENSE PRECIPITATION THAT IS FALLING.
AS A RESULT, THE INITIAL FORECAST INTENSITY WEIGHS MORE
TOWARDS THE 2.0 DVORAK FROM PGTW AND NFFN, RATHER THAN THE
QUIKSCAT SOLUTION, AS WELL AS SEA LEVEL PRESSURE OBSERVA-
TIONS FROM NEARBY FIJI. ENHANCED INFRARED SATELLITE IMAGERY
INDICATES THAT THE DEEPEST CONVECTION IS STILL ORIENTED
LINEARLY ALONG THE MONSOON TROUGH, RATHER THAN SYMMETRICALLY
ABOUT THE LLCC. THE SYSTEM IS FORECAST TO CONTINUE TO
STRENGTHEN UNDER LOW TO MODERATE VERTICAL WIND SHEAR AND
DUAL OUTFLOW CHANNELS FOR THE NEXT 12 HOURS. AFTER WHICH,
EXCESSIVE VERTICAL WIND SHEAR ASSOCIATED WITH A MID TO
UPPER-LEVEL TROUGH THAT HAS BEEN DIGGING EQUATORWARD FOR THE
LAST 2 DAYS, WILL WEAKEN THE CYCLONE. MODEL GUIDANCE IS
INITIALIZING THE SYSTEM VERY POORLY DUE TO THE RAPID
CONSOLIDATION OF THE LLCC AND IT BEING EMBEDDED IN VERY
TIGHT TROUGHING. HOWEVER, THE ENERGY ASSOCIATED WITH THIS
PART OF THE MONSOON TROUGH QUICKLY TRACKS SOUTH-SOUTHEASTWARD
OUT AHEAD OF THE MID-LEVEL TROUGH IN A HIGH AMPLITUDE PATTERN.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 040000Z IS 15 FEET. NEXT
WARNINGS AT 041500Z AND 050300Z.
=========================================================================
WTPS31 PGTW 20090404 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 25P (LIN) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 25P (LIN) WARNING NR 002
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   041200Z --- NEAR 19.7S 176.2W
     MOVEMENT PAST SIX HOURS - 175 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: 19.7S 176.2W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   050000Z --- 22.0S 175.8W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 165 DEG/ 14 KTS
    ---
   24 HRS, VALID AT:
   051200Z --- 24.7S 175.0W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 36 HR POSIT: 150 DEG/ 15 KTS
    ---
   36 HRS, VALID AT:
   060000Z --- 27.3S 173.2W
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
    ---
REMARKS:
041500Z POSITION NEAR 20.3S 176.1W.
TC 25P (LIN), LOCATED APPROXIMATELY 380 NM EAST-SOUTHEAST OF NADI,
FIJI, HAS TRACKED SOUTHWARD AT 13 KNOTS OVER THE PAST O6 HOURS.
ANIMATED INFRARED IMAGERY INDICATES THAT THE LOW LEVEL CIRCULATION
CENTER (LLCC) HAS TAKEN A MORE SOUTHWARD TRACK THAN PREVIOUSLY
FORECAST. ADDITIONALLY, OVER THE PAST 12 HOURS DEEP CONVECTION HAS
CONTINUED TO INCREASE OVER THE LLCC. TC 25P IS QUICKLY TRACKING
ALONG THE WESTERN PERIPHERY OF A MID-LEVEL RIDGE LOCATED TO THE EAST
OF THE SYSTEM. UPPER LEVEL ANALYSIS INDICATES THAT THE LLCC IS BEING
SUPPORTED BY DUAL OUTFLOW CHANNELS BUT IS IN MODERATE LEVELS OF
VERTICAL WIND SHEAR. TC 25P IS FORECAST TO CONTINUE TRACKING TOWARD
HIGHER LEVELS OF VERTICAL WIND SHEAR AND DECREASING SEA SURFACE
TEMPERATURES WHICH WILL KEEP TC 25P FROM DEVELOPING OVER THE NEXT 24
HOURS. FROM TAU 24 THROUGH TAU 36 TC 25P WILL BEGIN EXTRATROPICAL
TRANSISTION AND IS EXPECTED TO INCREASE IN INTENSITY AS AN
EXTRATROPICAL SYSTEM. MODEL GUIDANCE IS IN FAVORABLE AGREEMENT WITH
THE CURRENT FORECAST REASONING. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
041200Z IS 15 FEET. NEXT WARNINGS AT 050300Z AND 051500Z.//
=========================================================================
WTPS31 PGTW 20090405 03:00z
1. TROPICAL CYCLONE 25P (LIN) WARNING NR 003
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   050000Z --- NEAR 21.3S 175.3W
     MOVEMENT PAST SIX HOURS - 170 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   REPEAT POSIT: 21.3S 175.3W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   051200Z --- 23.5S 174.9W
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 160 DEG/ 13 KTS
    ---
   24 HRS, VALID AT:
   060000Z --- 25.9S 174.0W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
050300Z POSITION NEAR 21.9S 175.2W.
TC 25P (LIN), LOCATED APPROXIMATELY 20 NM WEST OF FUA'AMOTU,
TONGA, HAS TRACKED SOUTHWARD AT 09 KNOTS OVER THE PAST O6
HOURS. THE LOW LEVEL CIRCULATION CENTER (LLCC) IS JUST OFF-
SHORE OF FUA'AMOTU (NFTF). AT 04/2300Z STATION SEA LEVEL
PRESSURE (SLP) DROPPED TO IT'S LOWEST RECORDED READING OF
987 MB, AND SURFACE WINDS WERE LOGGED AT 35 KNOTS, GUSTING
TO 52 KNOTS (10-MINUTE AVERAGE). MORE RECENT SPECI METAR
REPORTS AT NFTF INDICATE THAT SLP HAS BEGUN TO RISE AS THE
LLCC TRACKS SOUTH, AND AWAY FROM THE TONGAN ISLAND. LIN IS
TRACKING DOWN THE SURFACE TROUGH IN A HIGH AMPLITUDE PATTERN
TOWARDS HIGH VERTICAL WIND SHEAR AND SEA SURFACE TEMPERATURES
BELOW 26 DEGREES CELSIUS. THESE FACTORS, COUPLED WITH A
STRONG BAROCLINIC BOUNDARY, WILL LEAD TO RAPID EXTRATROPICAL
TRANSITIONING WITHIN THE NEXT 24 HOURS. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 050000Z IS 17 FEET. NEXT WARNINGS AT 051500Z.
=========================================================================
WTPS31 PGTW 20090405 15:00z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 25P (LIN) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 25P (LIN) WARNING NR 004
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   051200Z --- NEAR 24.8S 174.3W
     MOVEMENT PAST SIX HOURS - 165 DEGREES AT 22 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
   BECOMING EXTRATROPICAL
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            055 NM NORTHWEST QUADRANT
   REPEAT POSIT: 24.8S 174.3W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   060000Z --- 29.3S 172.7W
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
051500Z POSITION NEAR 25.9S 173.9W.
TC 25P (LIN), LOCATED APPROXIMATELY 630 NM SOUTHEAST OF NADI, FIJI,
HAS TRACKED SOUTH-SOUTHEASTWARD AT 22 KNOTS OVER THE PAST O6
HOURS. ANIMATED INFRARED IMAGERY DEPICTS A LOW LEVEL CIRCULATION
CENTER (LLCC) THAT HAS STARTED EXTRATROPICAL TRANSITION (ET),
BECOMING ELONGATED TO THE SOUTHEAST. CURRENT INTENSITY ESTIMATES
HAVE RAPIDLY DECREASED FOR THE SYSTEM AS THE CONVECTION ASSOCIATED
WITH TC 25P HAS BECOME SHEARED FROM THE LLCC TO THE SOUTHEAST.
RAPIDLY INCREASING VERTICAL WIND SHEAR ASSOCIATED WITH A LONG WAVE
TROUGH SOUTHWEST OF LIN HAS BEEN THE PRIMARY FACTOR IN TC 25P
UNDERGOING ET. SEA SURFACE TEMPERATURES HAVE CONTINUED TO DECREASE
AS LIN CONTINUES TRACKING TO THE SOUTH-SOUTHEAST AND HAVE BECOME
UNFAVORABLE FOR FURTHER DEVELOPMENT. THESE FACTORS, COUPLED WITH A
STRONG BAROCLINIC BOUNDARY, WILL LEAD TO RAPID ET IN THE NEXT 12
HOURS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WARNING CENTER (NAVMARFCSTCEN). THE SYSTEM WILL BE CLOSELY MONI-
TORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
051200Z IS 17 FEET.//

Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.

Document: tropical_cyclone_lin_jtwc_advisories.htm Updated: 17 June 2020 [Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] [Privacy Policy]