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![]() Tropical Cyclone 201215 Southern Hemisphere Summary |
WTXS21 PGTW 20120229 08:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 130 NM EITHER SIDE OF A LINE FROM 12.3S 68.8E TO 16.4S 65.7E WITHIN THE NEXT 12 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 28 TO 32 KNOTS. METSAT IMAGERY AT 290530Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.9S 68.6E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 07 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.6S 69.4E, IS NOW LOCATED NEAR 12.9S 68.6E, APPROXIMATELY 400 NM SOUTHWEST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A TIGHTLY ORGANIZED LOW LEVEL CIRCULATION CENTER (LLCC) WITH ACTIVE CONVECTIVE BANDS OVER BOTH SEMICIRCLES. A 290452Z METOP-A MICROWAVE PASS SUPPORTS THE WELL DEFINED LLCC WITH DEEP CENTRAL CONVECTION BUILDING. UPPER LEVEL ANALYSIS INDICATES A MID-LATITUDE TROUGH HAS STARTED TO MOVE TO THE SOUTHEAST OF THE LLCC , HELPING TO ENHANCE THE STRONG POLEWARD OUTFLOW OBSERVED IN ANIMATED WATER VAPOR IMAGERY OVER THE PAST 12 HOURS. THE LLCC HAS BEEN SLOWLY TRACKING TOWARDS THE AXIS OF AN UPPER LEVEL SUBTROPICAL RIDGE AND INTO AN AREA OF WEAKER VERTICAL WIND SHEAR (LESS THAN 10 KNOTS). SEA SURFACE TEMPERATURES ARE BETWEEN 29 AND 30 DEGREES CELSIUS, SUPPORTING THE RECENT DEVELOPMENT AND FURTHER DEVELOPMENT OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 010800Z.// ========================================================================= WTXS32 PGTW 20120229 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 001// REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/290751Z FEB 12// AMPN/TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 001 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 291800Z --- NEAR 13.8S 67.3E 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: 13.8S 67.3E --- FORECASTS: 12 HRS, VALID AT: 010600Z --- 14.5S 66.0E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 235 DEG/ 07 KTS --- 24 HRS, VALID AT: 011800Z --- 15.3S 64.8E 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 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 220 DEG/ 05 KTS --- 36 HRS, VALID AT: 020600Z --- 16.1S 64.1E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 195 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 021800Z --- 16.9S 63.9E 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 - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 160 DEG/ 07 KTS --- 72 HRS, VALID AT: 031800Z --- 19.7S 65.0E 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 96 HR POSIT: 190 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 041800Z --- 22.2S 64.5E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 292100Z POSITION NEAR 14.0S 67.0E. TROPICAL CYCLONE (TC) 15S (FIFTEEN), LOCATED APPROXIMATELY 490 NM SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY AND A 291725Z AMSU MICROWAVE IMAGE SHOW INCREASED DEEP CONVECTION TIGHTLY WRAPPING INTO A WELL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC), FROM WHICH THE INITIAL POSITION WAS BASED. THE INITIAL INTENSITY WAS BASED ON PGTW, KNES, AND FMEE DVORAK ESTIMATES RANGING FROM 30 TO 35 KNOTS. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS LOCATED DIRECTLY UNDER THE RIDGE AXIS IN AN AREA OF LOW VERTICAL WIND SHEAR. AN UPPER LEVEL TROUGH TO THE WEST IS INCREASING OUTFLOW. TC 15S IS CURRENTLY TRACKING ALONG THE NORTHWESTERN PERIPHERY OF A LOW- TO MID-LEVEL STEERING RIDGE. AFTER TAU 36, THE SYSTEM IS EXPECTED TO TURN POLEWARD WHEN AN UPPER LEVEL TROUGH WEAKENS THE STEERING RIDGE. TC 15S SHOULD SIGNIFICANTLY WEAKEN BY TAU 72, DUE TO INCREASED VERTICAL WIND SHEAR ASSOCIATED WITH AN APPROACHING UPPER LEVEL TROUGH. TC 15S WILL BEGIN TO TURN SOUTHWESTWARD AS THE LOW LEVEL STEERING RIDGE REBUILDS IN TO THE SOUTH. THE SYSTEM WILL DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE BY TAU 96. NUMERICAL MODEL GUIDANCE SUPPORTS THE POLEWARD TURN AND DISSIPATION SCENARIO. HOWEVER, SEVERAL MODELS INCLUDING GFDN, WBAR, AND EGRR EXTEND FARTHER WESTWARD BEFORE TURNING POLEWARD IN THE EARLY TAUS. THIS FORECAST IS IN AGREEMENT WITH ECMWF, NOGAPS, AND GFS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 291800Z IS 8 FEET. NEXT WARNINGS AT 010900Z AND 012100Z. THIS WARNING SUPERSEDES AND CANCELS REF A, JOINT TYPHOON WRNCEN 290751Z FEB 12 TROPICAL CYCLONE FORMATION ALERT ========================================================================= WTXS32 PGTW 20120301 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 002// REFER TO TROPICAL CYCLONE 14S (IRINA) WARNINGS (WTXS31 PGTW) RMKS/ 1. TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 002 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 010600Z --- NEAR 14.7S 64.8E MOVEMENT PAST SIX HOURS - 245 DEGREES AT 16 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: 14.7S 64.8E --- FORECASTS: 12 HRS, VALID AT: 011800Z --- 15.8S 63.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 230 DEG/ 04 KTS --- 24 HRS, VALID AT: 020600Z --- 16.3S 62.7E 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 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 195 DEG/ 04 KTS --- 36 HRS, VALID AT: 021800Z --- 17.0S 62.5E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 175 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 030600Z --- 17.8S 62.6E 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 - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 165 DEG/ 07 KTS --- 72 HRS, VALID AT: 040600Z --- 20.5S 63.4E 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 96 HR POSIT: 215 DEG/ 07 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 050600Z --- 22.7S 61.7E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 010900Z POSITION NEAR 15.0S 64.4E. TROPICAL CYCLONE (TC) 15S, LOCATED APPROXIMATELY 525 NM NORTHEAST OF PORT LOUIS, MAURITIUS, HAD TRACKED WEST-SOUTHWESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. A RECENT 12-HOUR ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE CONVECTIVE BANDING HAS MAINTAINED DEPTH EVEN AS ITS OVERALL STRUCTURE ELONGATED IN RESPONSE TO A MID- LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST. THE INITIAL POSITION WAS EXTRAPOLATED FROM A 010432Z AMSU-B MICROWAVE IMAGE AND THE INITIAL INTENSITY WAS BASED ON CONGRUENT DVORAK ESTIMATES FROM PGTW AND FMEE. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS UNDER A NARROW RIDGE AXIS IN AN AREA OF LOW (05-10 KNOT) VERTICAL WIND SHEAR (VWS). TC 15S IS, AT THE MOMENT, TRACKING ALONG THE NORTHWEST PERIPHERY OF A LOW- TO MID-LAYERED SUBTROPICAL RIDGE (STR). BY TAU 36, THE AFOREMENTIONED MID-LATITUDE TROUGH WILL ERODE THE STEERING RIDGE AND CAUSE THE CYCLONE TO TRACK POLEWARD. BY TAU 72, A SECONDARY STR WILL ASSUME STEERING AND DEFLECT A WEAKENED SYSTEM SOUTHWESTWARD. TC 15S WILL SEE MODERATE INTENSIFICATION OVER THE NEXT 48 HOURS WITH FAVORABLE VWS AND IMPROVED POLEWARD OUTFLOW ASSOCIATED WITH THE APPROACHING TROUGH. AFTER TAU 48, RAPIDLY INCREASING VWS ASSOCIATED WITH THE PREVAILING WESTERLIES WILL ERODE THE SYSTEM, CAUSING ITS EVENTUAL DISSIPATION BY TAU 96. THE AVAILABLE NUMERICAL GUIDANCE IS IN LOOSE AGREEMENT WITH WBAR AS THE SOLE RIGHT OUTLIER. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 010600Z IS 9 FEET. NEXT WARNINGS AT 012100Z AND 020900Z. REFER TO TROPICAL CYCLONE 14S (IRINA) WARNINGS (WTXS31 PGTW) FOR TWELVE-HOURLY UPDATES. ========================================================================= WTXS32 PGTW 20120301 21:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 003// REFER TO TROPICAL CYCLONE 14S (IRINA) WARNINGS (WTXS31 PGTW) RMKS/ 1. TROPICAL CYCLONE 15S (FIFTEEN) WARNING NR 003 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 011800Z --- NEAR 15.3S 63.7E MOVEMENT PAST SIX HOURS - 245 DEGREES AT 07 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 DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 15.3S 63.7E --- FORECASTS: 12 HRS, VALID AT: 020600Z --- 15.9S 62.7E 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: 200 DEG/ 04 KTS --- 24 HRS, VALID AT: 021800Z --- 16.6S 62.4E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 012100Z POSITION NEAR 15.4S 63.4E. TROPICAL CYCLONE (TC) 15S, LOCATED APPROXIMATELY 460 NM NORTHEAST OF PORT LOUIS, MAURITIUS, HAS TRACKED WEST-SOUTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT TC 15S HAS WEAKENED SIGNIFICANTLY OVER THE PAST 12 HOURS WITH DISORGANIZED DEEP CONVECTION FLARING SOUTH OF THE CENTER. A 011704Z ASCAT IMAGE SHOWS A DEFINED CIRCULATION; HOWEVER, WINDS HAVE DECREASED TO 20-25 KNOTS WITH ONE ISOLATED 30-KNOT WIND DISPLACED OVER 60 NM SOUTH OF THE CENTER. A SHIP OBSERVATION AT 01/20Z, LOCATED APPROXIMATELY 45 NM EAST, SHOWED SLP NEAR 1003 MB AND WINDS 070/30 KNOTS. THIS WEAKENING IS FURTHER EVIDENT IN A 011729Z TRMM IMAGE SHOWING WEAK LOW-LEVEL CONVECTIVE BANDING WITH AN ISOLATED AREA OF DEEP CONVECTION SHEARED SOUTH OF CENTER. ADDITIONALLY, DVORAK ESTIMATES HAVE DECREASED TO 25-30 KNOTS. TC 15S IS FORECAST TO TRACK WEST-SOUTHWESTWARD TO SOUTHWARD WHILE MAINTAINING A 25-30 KNOT INTENSITY. DYNAMIC MODEL GUIDANCE INDICATES A SLIGHT POSSIBILITY OF REGENERATION BUT OVERALL ENVIRONMENTAL CONDITIONS ARE MARGINAL. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WARNING CENTER. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 011800Z IS 7 FEET. REFER TO TROPICAL CYCLONE 14S (IRINA) WARNINGS (WTXS31 PGTW) FOR TWELVE-HOURLY UPDATES.//
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Document: tropical_cyclone_201215.htm | Updated: 5 March 2012 |