Tropical Cyclones
[Index] | Tropical Cyclone 201318 : JTWC Advisories |
Season 2012-2013 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
---> Tropical Cyclone 201318 Track Map and Data |
WTXS22 PGTW 20130224 02:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN A 160 NM RADIUS OF 11.2S 98.3E 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 25 TO 30 KNOTS. METSAT IMAGERY AND SYNOPTIC DATA AT 240130Z INDICATE THAT A CIRCULATION CENTER IS LOCATED NEAR 11.2S 98.3E. THE SYSTEM IS MOVING NORTHWARD AT 06 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.3S 98.0E, IS NOW LOCATED NEAR 11.2S 98.3E, APPROXIMATELY 100 NM EAST- NORTHEAST OF COCOS ISLAND, AUSTRALIA. ANIMATED INFRARED SATELLITE IMAGERY INDICATES A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH IMPROVED DEEP CONVECTIVE BANDING OVER THE WESTERN SEMI- CIRCLE. A 232222Z SSMIS IMAGE SHOWS AN ELONGATED LLCC WITH FRAGMENTED DEEP CONVECTIVE BANDING WRAPPING FROM THE SOUTH QUADRANT INTO THE NORTH QUADRANT AND TIGHTLY-CURVED SHALLOW CONVECTIVE BANDING ELSEWHERE. SURFACE OBSERVATIONS FROM COCOS ISLAND INDICATE SUSTAINED SURFACE WINDS AT 15 TO 20 KNOTS WITH SLP NEAR 1001 MB AND 24-HOUR SLP DECREASE OF 3 MB. UPPER-LEVEL ANALYSIS INDICATES THAT THE LLCC IS LOCATED JUST EQUATORWARD OF THE SUBTROPICAL RIDGE AXIS AND IS UNDER MODERATE TO HIGH (20 TO 30 KNOTS) VERTICAL WIND SHEAR WITH GOOD POLEWARD OUTFLOW. DYNAMIC MODELS INDICATE SLOW DEVELOPMENT OVER THE NEXT ONE TO TWO DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 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 250200Z.// ========================================================================= WTXS33 PGTW 20130224 15:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 001// REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/240153Z FEB 13// AMPN/ REF A IS A TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 001 03 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 241200Z --- NEAR 12.6S 97.4E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 12 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: 12.6S 97.4E --- FORECASTS: 12 HRS, VALID AT: 250000Z --- 13.1S 97.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 180 DEG/ 03 KTS --- 24 HRS, VALID AT: 251200Z --- 13.7S 97.1E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 165 DEG/ 02 KTS --- 36 HRS, VALID AT: 260000Z --- 14.1S 97.2E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 120 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 261200Z --- 14.4S 97.7E 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 - 070 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 105 DEG/ 02 KTS --- 72 HRS, VALID AT: 271200Z --- 14.6S 98.6E 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 - 085 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 100 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 281200Z --- 15.0S 101.1E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 110 DEG/ 10 KTS --- 120 HRS, VALID AT: 011200Z --- 16.2S 105.1E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 241500Z POSITION NEAR 12.7S 97.3E. TROPICAL CYCLONE (TC) 18S, LOCATED APPROXIMATELY 45 NM SOUTHEAST OF COCOS ISLAND, AUSTRALIA, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FULLY EXPOSED AND WELL DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION SHEARED 30NM WEST OF THE LLCC. A 241059Z SSMIS MICROWAVE IMAGE SHOWS THE LLCC HAS BECOME MORE TIGHTLY WRAPPED OVER THE PAST 12 HOURS DESPITE THE HIGH VERTICAL WIND SHEAR (VWS) ON THE SYSTEM. THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON THE WELL-DEFINED LLCC IN THE MSI. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS, WHICH IS SLIGHTLY HIGHER THAN DVORAK INTENSITY ESTIMATES FROM PGTW AND KNES DUE TO SURFACE OBSERVATIONS AT COCOS ISLAND, 45 NM NORTHWEST OF THE SYSTEM, AND THE IMPROVING STRUCTURE. AN OLDER 240500Z OSCAT PASS ADDITIONALLY SHOWED SOME 35 KNOT WINDS NEAR THE LLCC. UPPER-LEVEL ANALYSIS REVEALS TC 18S IS IN A MARGINAL ENVIRONMENT AS FAVORABLE DIFFLUENCE ALOFT IS BEING OFFSET BY HIGH (20 TO 30 KNOT) VWS. TC 18S CURRENTLY TRACKING ERRATICALLY AS THERE ARE COMPETING STEERING INFLUENCES FROM THE NEAR EQUATORIAL RIDGE TO THE NORTH AND THE SUBTROPICAL STEERING RIDGE TO THE SOUTH. TC 18S IS FORECAST TO SLOWLY DRIFT SOUTH IN THIS WEAK STEERING ENVIRONMENT FOR THE NEXT TWO DAYS UNTIL THE NEAR EQUATORIAL RIDGE TO THE NORTH AMPLIFIES AND DRIVES THE SYSTEM EAST THROUGH THE REST OF THE FORECAST PERIOD. TC 18S IS FORECAST TO INTENSIFY THROUGH THE FORECAST PERIOD AS VWS IS FORECAST TO WEAKEN AND OUTFLOW IMPROVES. DYNAMIC MODEL GUIDANCE IS SPREAD THROUGH THE NEXT 48 HOURS DUE TO THE WEAK STEERING ENVIRONMENT, BUT GENERALLY AGREES ON THE EASTWARD TRACK AFTER TAU 48. DUE TO THIS SPREAD AND THE CURRENT WEAK STEERING ENVIRONMENT THERE IS LOW CONFIDENCE IN THE FORECAST TRACK WHICH IS POSITIONED CLOSE TO MULTI-MODEL CONSENSUS. THIS WARNING SUPERSEDES AND CANCELS REF A, JOINT TYPHOON WRNCEN PEARL HARBOR HI 240153Z FEB 13 TROPICAL CYCLONE FORMATION ALERT (WTXS22 PGTW 240200). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 241200Z IS 10 FEET. NEXT WARNINGS AT 250300Z AND 251500Z. REFER TO TROPICAL CYCLONE 16S (HARUNA) WARNINGS (WTXS31 PGTW) AND TROPICAL CYCLONE 17S (RUSTY) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.// ========================================================================= WTXS33 PGTW 20130225 03:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 002// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 002 03 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 250000Z --- NEAR 13.5S 98.3E MOVEMENT PAST SIX HOURS - 150 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT REPEAT POSIT: 13.5S 98.3E --- FORECASTS: 12 HRS, VALID AT: 251200Z --- 13.9S 98.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 150 DEG/ 03 KTS --- 24 HRS, VALID AT: 260000Z --- 14.4S 98.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 130 DEG/ 02 KTS --- 36 HRS, VALID AT: 261200Z --- 14.7S 99.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 110 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 270000Z --- 14.9S 99.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 090 DEG/ 05 KTS --- 72 HRS, VALID AT: 280000Z --- 14.9S 102.0E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 095 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 010000Z --- 15.1S 105.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 095 DEG/ 10 KTS --- 120 HRS, VALID AT: 020000Z --- 15.6S 109.4E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 250300Z POSITION NEAR 13.6S 98.3E. TROPICAL CYCLONE (TC) 18S, LOCATED APPROXIMATELY 120 NM SOUTHEAST OF COCOS ISLAND, AUSTRALIA, HAS TRACKED SOUTH-SOUTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN EXPOSED BUT WELL-DEFINED LOW-LEVEL CIRCULATION CENTER WITH DEEP CONVECTION SHEARED ABOUT 45 NM WEST OF THE CENTER DUE TO STRONG EASTERLY VERTICAL WIND SHEAR (VWS). TC 18S HAS CONTINUED TO STRUGGLE DUE TO THE POOR UPPER-LEVEL ENVIRONMENT, HOWEVER, A 242014Z AMSU IMAGE INDICATES BETTER ORGANIZED SHALLOW BANDING WRAPPING INTO A WELL-DEFINED LLCC. A 241434Z ASCAT IMAGE SHOWED 40 TO 45 KNOT WINDS OVER THE NORTH QUADRANT AND SURFACE OBSERVATIONS FROM COCOS ISLAND HAVE REMAINED STEADY AT 30 TO 35 KNOTS SUSTAINED WITH GUSTS TO 40 TO 50 KNOTS. THE INITIAL INTENSITY IS ASSESSED AT 40 KNOTS, SLIGHTLY HIGHER THAN DVORAK INTENSITY ESTIMATES OF 35 KNOTS, BASED ON THE ASCAT IMAGE. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED ON THE EXPOSED CENTER IN VISIBLE IMAGERY. TC 18S IS FORECAST TO TRACK EASTWARD UNDER THE STEERING INFLUENCE OF THE NEAR- EQUATORIAL RIDGE THROUGH THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT, THEREFORE, THE JTWC FORECAST IS POSITIONED CLOSE TO THE MULTI-MODEL CONSENSUS. TC 18S IS EXPECTED TO SLOWLY INTENSIFY THROUGH TAU 120 DUE TO PERSISTENT MODERATE TO STRONG VWS. DUE TO THE MARGINAL ENVIRONMENT, THERE IS UNCERTAINTY IN THE EXTENDED INTENSITY FORECAST, WHICH MAY BE SIGNIFICANTLY LOWER THAN THE 60 KNOTS CURRENTLY FORECAST TO OCCUR NEAR TAU 120. THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO THE SHEARED NATURE OF THE SYSTEM AND LARGE DIFFERENCES IN MODEL TRACK SPEED THROUGHOUT THE FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 250000Z IS 11 FEET. NEXT WARNINGS AT 251500Z AND 260300Z. REFER TO TROPICAL CYCLONE 16S (HARUNA) FINAL WARNING (WTXS31 PGTW). REFER TO TROPICAL CYCLONE 17S (RUSTY) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.// ========================================================================= WTXS33 PGTW 20130225 15:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 003 03 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 251200Z --- NEAR 14.6S 98.9E MOVEMENT PAST SIX HOURS - 140 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 050 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: 14.6S 98.9E --- FORECASTS: 12 HRS, VALID AT: 260000Z --- 14.9S 99.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 125 DEG/ 02 KTS --- 24 HRS, VALID AT: 261200Z --- 15.1S 99.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 100 DEG/ 02 KTS --- 36 HRS, VALID AT: 270000Z --- 15.2S 100.0E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 090 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 271200Z --- 15.2S 100.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 095 DEG/ 03 KTS --- 72 HRS, VALID AT: 281200Z --- 15.3S 101.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 095 DEG/ 09 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 011200Z --- 15.6S 105.5E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 105 DEG/ 10 KTS --- 120 HRS, VALID AT: 021200Z --- 16.6S 109.7E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 251500Z POSITION NEAR 14.7S 99.0E. TROPICAL CYCLONE (TC) 18S, LOCATED APPROXIMATELY 980 NM WEST-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS THE MAIN CONVECTION CONTINUES TO BE SHEARED WESTWARD, FULLY EXPOSING A LOW LEVEL CIRCULATION CENTER THAT APPEARS TO HAVE SLIGHTLY UNRAVELED. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION AND THE INITIAL INTENSITY IS BASED ON THE HIGH END OF DVORAK ESTIMATES FROM PGTW, KNES, AND APRF. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS WELL TO THE NORTH OF THE RIDGE AXIS IN AN AREA OF MODERATE TO STRONG (20-30 KNOT) EASTERLY VERTICAL WIND SHEAR (VWS). THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE NEAR-EQUATORIAL RIDGE TO THE NORTH AND IS EXPECTED TO REMAIN ON THIS TRACK THROUGHOUT THE FORECAST PERIOD. TC 18S WILL CONTINUE TO STRUGGLE OVER THE NEXT TWO DAYS AS STRONG VWS WILL PERSIST. AFTER TAU 48, THE SYSTEM WILL BEGIN TO INTENSIFY AS THE VWS DECREASES AS THE RIDGE TO THE SOUTH IS WEAKENED BY THE APPROACH OF A MID-LATITUDE TROUGH. THE AVAILABLE NUMERICAL GUIDANCE IS IN OVERALL AGREEMENT WITH AN EASTWARD PROGRESSION OF THE CYCLONE; HOWEVER, THERE ARE SIGNIFICANT DIFFERENCES AMONG THE MEMBERS IN TRACK SPEED WITH GFDN THE FASTEST AND WBAR THE SLOWEST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 251200Z IS 12 FEET. NEXT WARNINGS AT 260300Z AND 261500Z. REFER TO TROPICAL CYCLONE 17S (RUSTY) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES. ========================================================================= WTXS33 PGTW 20130226 03:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 004 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 260000Z --- NEAR 14.9S 97.9E MOVEMENT PAST SIX HOURS - 250 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: 14.9S 97.9E --- FORECASTS: 12 HRS, VALID AT: 261200Z --- 15.3S 98.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 100 DEG/ 02 KTS --- 24 HRS, VALID AT: 270000Z --- 15.4S 98.5E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 36 HR POSIT: 090 DEG/ 02 KTS --- 36 HRS, VALID AT: 271200Z --- 15.4S 99.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 48 HR POSIT: 090 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 280000Z --- 15.4S 99.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 095 DEG/ 03 KTS --- 72 HRS, VALID AT: 010000Z --- 15.5S 100.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 100 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 020000Z --- 15.8S 102.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 105 DEG/ 06 KTS --- 120 HRS, VALID AT: 030000Z --- 16.3S 105.2E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 260300Z POSITION NEAR 15.0S 97.9E. TROPICAL CYCLONE (TC) 18S, LOCATED APPROXIMATELY 180 NM SOUTH- SOUTHEAST OF COCOS ISLAND, AUSTRALIA, HAS TRACKED WEST-SOUTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION SHEARED WEST OF THE CENTER. A 260106Z SSMIS IMAGE DEPICTS WEAK, SHALLOW CONVECTIVE BANDING WRAPPING LOOSELY INTO A DEFINED LLCC. TC 18S HAS TRACKED ERRATICALLY OVER THE PAST 12 HOURS. HOWEVER, RECENT MSI INDICATES THAT THE SYSTEM IS NOW TRACKING SLOWLY EASTWARD. DUE TO THE BROAD NATURE OF THE LLCC AND LACK OF VISIBLE IMAGERY, THERE HAS BEEN LOW CONFIDENCE IN THE INITIAL POSITION OVER THE PAST 12 HOURS; HOWEVER, THERE IS INCREASED CONFIDENCE IN THE CURRENT POSITION BASED ON THE MSI, WHICH SHOWED THE CENTER WAS LOCATED ABOUT 80 NM WEST OF THE 25/12Z TAU 12 FORECASTED POSITION. TC 18S IS LOCATED WITHIN A COMPETING STEERING ENVIRONMENT BETWEEN A STRONG HIGH TO THE SOUTH AND A NEAR-EQUATORIAL RIDGE (NER) TO THE NORTH. TC 18S IS FORECAST TO TRACK SLOWLY EASTWARD THROUGH TAU 48 DUE TO THE COMPLEX STEERING ENVIRONMENT AND IS EXPECTED TO ACCELERATE EASTWARD AFTER TAU 48 AS THE SUBTROPICAL HIGH TO THE SOUTH WEAKENS AND THE NER BECOMES THE DOMINANT STEERING INFLUENCE. DYNAMIC MODEL GUIDANCE HAS TRENDED TOWARD A MUCH SLOWER OVERALL TRACK WITH GFS AND GFDN INDICATING EXCESSIVELY FAST TRACKS, THEREFORE, THIS FORECAST IS POSITIONED SLOWER THAN THE MULTI-MODEL CONSENSUS FAVORING THE ECMWF TRACKER. THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. TC 18S IS FORECAST TO MAINTAIN AT 35 KNOTS THROUGH TAU 48 THEN WILL GRADUALLY INTENSIFY TO A PEAK INTENSITY OF 55 KNOTS BY TAU 120 AS VERTICAL WIND SHEAR DECREASES. THERE IS LOW CONFIDENCE IN THE INTENSITY FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 260000Z IS 15 FEET. NEXT WARNINGS AT 261500Z AND 270300Z. REFER TO TROPICAL CYCLONE 17S (RUSTY) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.// ========================================================================= WTXS33 PGTW 20130226 15:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 005 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 261200Z --- NEAR 15.5S 98.0E MOVEMENT PAST SIX HOURS - 165 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 025 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: 15.5S 98.0E --- FORECASTS: 12 HRS, VALID AT: 270000Z --- 15.6S 98.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 090 DEG/ 01 KTS --- 24 HRS, VALID AT: 271200Z --- 15.6S 98.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 36 HR POSIT: 090 DEG/ 02 KTS --- 36 HRS, VALID AT: 280000Z --- 15.6S 98.9E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 48 HR POSIT: 100 DEG/ 02 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 281200Z --- 15.7S 99.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 105 DEG/ 03 KTS --- 72 HRS, VALID AT: 011200Z --- 16.0S 100.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 100 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 021200Z --- 16.3S 102.8E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 095 DEG/ 06 KTS --- 120 HRS, VALID AT: 031200Z --- 16.5S 105.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 261500Z POSITION NEAR 15.5S 98.0E. TROPICAL CYCLONE (TC) 18S, LOCATED APPROXIMATELY 1000 NM WEST-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTH-SOUTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE MAIN CONVECTION REMAINS DETACHED FROM A FULLY EXPOSED LOW LEVEL CIRCULATION THAT HAS BECOME MORE ELONGATED AND IRREGULAR, MAKING IT DIFFICULT TO PINPOINT THE CENTER. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION WITH POOR CONFIDENCE. THE INITIAL INTENSITY, ASSESSED HIGHER THAN MULTI-AGENCY SUBJECTIVE DVORAK ESTIMATES, IS EXTRAPOLATED FROM RECENT SCATTEROMETER DATA. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS IN AN AREA OF STRONG (30-40 KNOT) EASTERLY VERTICAL WIND SHEAR (VWS). THE CYCLONE IS CURRENTLY IN A WEAK STEERING ENVIRONMENT BETWEEN THE NEAR-EQUATORIAL RIDGE (NER) TO THE NORTH AND A SUBTROPICAL RIDGE (STR) TO THE SOUTH RESULTING IN A VERY SLOW EASTWARD DRIFT. IT IS EXPECTED TO REMAIN IN THIS STATE OVER THE NEXT 48 HOURS UNTIL THE STR RECEDES TO THE EAST. AT THAT STAGE, THE NER WILL REBUILD AND RESUME STEERING AND TRACK THE CYCLONE FASTER EASTWARD. TC 18S IS EXPECTED TO STRUGGLE AT MODERATE GALE INTENSITY OVER THE NEXT 48 HOURS WITH A DISTINCT POSSIBILITY OF DISSIPATION. AFTER TAU 48, SHOULD THE CYCLONE SURVIVE, DECREASING VWS WILL CONTRIBUTE TO A GRADUAL INTENSIFICATION. THE AVAILABLE NUMERICAL GUIDANCE ARE IN OVERALL AGREEMENT IN EVENTUALLY TRACKING THE VORTEX EASTWARD BUT WITH SIGNIFICANT DIFFERENCES IN TRACK SPEED. GIVEN THE UNCERTAINTY IN THE STEERING MECHANISM, THERE IS LOW CONFIDENCE IN THE JTWC TRACK AND INTENSITY FORECASTS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 261200Z IS 17 FEET. NEXT WARNINGS AT 270300Z AND 271500Z. REFER TO TROPICAL CYCLONE 17S (RUSTY) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES. // ========================================================================= WTXS33 PGTW 20130227 03:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 006// RMKS/ 1. TROPICAL CYCLONE 18S (EIGHTEEN) WARNING NR 006 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 270000Z --- NEAR 15.3S 98.6E MOVEMENT PAST SIX HOURS - 075 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 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 98.6E --- FORECASTS: 12 HRS, VALID AT: 271200Z --- 15.2S 99.4E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 270300Z POSITION NEAR 15.3S 98.8E. TROPICAL CYCLONE (TC) 18S, LOCATED APPROXIMATELY 215 NM SOUTH- SOUTHEAST OF COCOS ISLAND, HAS TRACKED EAST-NORTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A LOW LEVEL CIRCULATION WITH THE MAJORITY OF DEEP CONVECTION SHEARED 130 NM TO THE WEST. THE LOW LEVEL CIRCULATION CENTER (LLCC) REMAINS WELL DEFINED, BUT HAS WEAKENED OVER THE PAST 12 HOURS. RECENT SCATTEROMETRY DATA INDICATES THE WINDS AROUND THE NORTHERN AND SOUTHWESTERN PERIPHERY ARE AT BEST 30 KNOTS, WITH A SLIGHT RELAXATION OF THE STRONGEST WINDS OVER THE PAST 18 HOURS. DVORAK ESTIMATES HAVE INDICATED A WEAKENING TREND FOR THE PAST 12 HOURS, SUPPORTING OBSERVATIONS IN THE SCATTEROMETRY DATA. THE LLCC IS CURRENTLY TRACKING EASTWARD OVER A COLD POOL OF UNFAVORABLE OCEAN WATERS (24 TO 26 DEGREES CELSIUS), LEADING TO FURTHER WEAKENING OF THE LLCC. UPPER LEVEL ANALYSIS INDICATES STRONG EASTERLY FLOW ALOFT IS CREATING MODERATE TO HIGH (20 TO 30 KNOTS) VERTICAL WIND SHEAR (VWS) OVER THE LLCC, PREVENTING THE OBSERVED DEEP CONVECTION FROM BUILDING TOWARDS THE CENTER OF THE SYSTEM. MODEL GUIDANCE HAS SHIFTED OVER THE PAST 12 HOURS AND NOW INDICATES THE LLCC WILL DISSIPATE COMPLETELY OVER THE NEXT 24 TO 48 HOURS. THERE REMAINS A SLIGHT CHANCE THE LLCC WILL MAKE IT INTO A MORE FAVORABLE ENVIRONMENT IN THE NEXT 48 TO 72 HOURS, LEADING TO A REDEVELOPMENT OF THE SYSTEM. BASED ON THE INCREASING VWS AND WEAKENING LLCC, THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270000Z IS 14 FEET. REFER TO TROPICAL CYCLONE 17S (RUSTY) WARNINGS (WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.//
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
Document: tropical_cyclone_201318_jtwc_advisories.htm
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