Tropical Cyclones
[Index] | Tropical Cyclone HETTIE : JTWC Advisories |
Season 2008-2009 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
---> Tropical Cyclone HETTIE Track Map and Data |
WTPS21 PGTW 20090128 02:00z RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 090 NM EITHER SIDE OF A LINE FROM 20.0S 177.0W TO 22.7S 179.6W 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 27 TO 32 KNOTS. METSAT IM- AGERY AT 272330Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 20.2S 177.2W. THE SYSTEM IS MOVING SOUTHWESTWARD AT 05 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 17.3S 176.1W, IS NOW LOCATED NEAR 20.2S 177.2W, APPROXIMATELY 335 NM EAST- SOUTHEAST OF NADI, FIJI. RECENT ANIMATED MULTISPECTRAL IMAGERY CONTINUES TO INDICATE A WELL-DEFINED CIRCULATION, BUT THE LOW LEVEL CIRCULATION CENTER (LLCC) HAS BECOME PARTIALLY EXPOSED OVER THE PAST SIX HOURS. MICROWAVE IMAGERY INDICATES THAT THE CONVECTION IS BEING SHEARED TO THE EAST OF THE LLCC. THE MOST RECENT QUIKSCAT AND WINDSAT IMAGES INDICATE WINDS OF 25 TO 30 KNOTS NEAR THE CENTER OF THE CIRCULATION AND 30 TO 35 KNOTS ALONG THE EASTERN PERIPHERY OF THE LLCC. THE UPPER LEVEL ENVIRONMENT REMAINS MARGINAL WITH MODERATE VERTICAL WIND SHEAR, HOWEVER, AN UPPER LEVEL TROUGH THAT HAS BEEN LOCATED TO THE WEST OF THE SYSTEM CONTINUES TO TRACK EASTWARD. THIS COULD ALLOW THE CURRENTLY STRONG SHEAR GRADIENT TO RELAX AND ALLOW CONVECTION TO RE-BUILD OVER THE LLCC. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. DUE TO THE WELL-DEFINED LLCC AND POTENTIAL FOR A DECREASE IN VERTICAL WIND SHEAR, 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 290200Z.// ========================================================================= WTPS31 PGTW 20090128 15:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 11P (HETTIE) WARNING NR 001// RMKS/ 1. TROPICAL CYCLONE 11P (HETTIE) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 281200Z --- NEAR 21.7S 177.5W MOVEMENT PAST SIX HOURS - 195 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: 21.7S 177.5W --- FORECASTS: 12 HRS, VALID AT: 290000Z --- 22.7S 178.3W MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 24 HR POSIT: 245 DEG/ 06 KTS --- 24 HRS, VALID AT: 291200Z --- 23.2S 179.4W MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 36 HR POSIT: 260 DEG/ 06 KTS --- 36 HRS, VALID AT: 300000Z --- 23.4S 179.4E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 48 HR POSIT: 275 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 301200Z --- 23.3S 178.4E MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 281500Z POSITION NEAR 22.0S 177.7W. TROPICAL CYCLONE (TC) 11P (HETTIE), LOCATED APPROXIMATELY 315 NM SOUTHEAST OF SUVA, FIJI, HAS TRACKED SOUTH-SOUTHWEST AT 07 KNOTS OVER THE PAST 06 HOURS. RECENT ANIMATED INFRARED IMAGERY AND A 280915Z AMSUB MICROWAVE IMAGE SHOWS DEEP CONVECTION FLARING ON THE SOUTHEASTERN PERIPHERY OF THE LOW LEVEL CIRCULATION CENTER (LLCC). UPPER LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT ALOFT WITH STRONG DIFFLUENCE OVER THE STORM PROVIDING GOOD OUTFLOW, ALTHOUGH MODERATE WESTERLY VERTICAL WIND SHEAR (VWS) CONTINUES TO LIMIT SIGNIFICANT DEVELOPMENT OF THE SYSTEM. CURRENT INTENSITY IS BASED UPON DVORAK ESTIMATES OF 35 KNOTS FROM PGTW ALONG WITH SCATTEROMETRY DATA WHICH DEPICTS WINDS OF 30 TO 40 KNOTS NEAR THE CENTER. IN THE NEAR TERM, THE SYSTEM WILL MAINTAIN INTENSITY IN THE MARGINALLY FAVORABLE ENVIRONMENT WHILE TRACKING SOUTH-SOUTHWESTWARD UNDER THE INFLUENCE OF THE SUBTROPICAL RIDGE TO THE SOUTHEAST. AFTER TAU 12, A LOW- TO MID-LEVEL RIDGE BUILDING SOUTH OF THE STORM IS EXPECTED TO BECOME THE DOMINANT STEERING INFLUENCE AND WILL TURN THE SYSTEM WESTWARD. THE STORM WILL MAINTAIN INTENSITY THROUGH TAU 12 AND THEN BEGIN TO WEAKEN AS VWS INCREASES AND CONVECTION IS SHEARED AWAY FROM THE LLCC DUE TO AN APPROACHING MID- TO UPPER-LEVEL SHORTWAVE TROUGH. THE STORM IS EXPECTED TO DISSIPATE OVER WATER BY TAU 36. THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 280151Z JAN 08 TROPICAL CYCLONE FORMATION ALERT (WTPS21 PGTW 280200) MAXIMUM SIGNIFICANT WAVE HEIGHT AT 281200Z IS 10 FEET. NEXT WARNINGS AT 290300Z AND 291500Z. ========================================================================= WTPS31 PGTW 20090129 03:00z 1. TROPICAL CYCLONE 11P (HETTIE) WARNING NR 002 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 290000Z --- NEAR 22.5S 177.8W MOVEMENT PAST SIX HOURS - 190 DEGREES AT 05 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 22.5S 177.8W --- FORECASTS: 12 HRS, VALID AT: 291200Z --- 23.4S 178.6W 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: 245 DEG/ 05 KTS --- 24 HRS, VALID AT: 300000Z --- 23.8S 179.5W MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 290300Z POSITION NEAR 22.7S 178.0W. TROPICAL CYCLONE (TC) 11P (HETTIE), LOCATED APPROXIMATELY 390 NM SOUTHEAST OF NADI, FIJI, HAS TRACKED SOUTHWARD AT 07 KNOTS OVER THE PAST 06 HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A FULLY EXPOSED AND WEAKENED LOW LEVEL CIRCULATION CENTER LOCATED APPROXIMATELY ONE DEGREE TO THE NORTHWEST OF SIGNIFICANTLY WARMED CLOUD TOPS/CONVECTION. TWELVE HOUR SATELLITE INTENSITY TRENDS FROM PGTW, KNES AND FMEE REFLECT A WEAKENING SYSTEM WITH CURRENT INTENSITY ESTIMATES RANGING FROM 30 TO 35 KNOTS. A 281754Z QUIKSCAT IMAGE CONFIRMS A 30 TO 35 KNOT (FLAGGED) SYSTEM AS WELL. THE CYCLONE IS FORECAST TO TRACK SOUTH TO SOUTHWESTWARD OVER THE NEXT 24 HOURS WHILE REMAINING BELOW WARNING CRITERIA. THE SYSTEM WILL CONTINUE TO CONTEND WITH EXCESSIVE VERTICAL WIND SHEAR AHEAD OF A SHORTWAVE TROUGH TO THE WEST MAKING REGENERATION VERY UNLIKELY. 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 290000Z IS 10 FEET.
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
Document: tropical_cyclone_hettie_jtwc_advisories.htm
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