Tropical Cyclones
[Index] | Tropical Cyclone ATU : JTWC Advisories |
Season 2010-2011 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
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WTPS21 PGTW 20110218 05:30z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 160 NM EITHER SIDE OF A LINE FROM 14.0S 169.1E TO 17.9S 171.2E 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 AT 180500Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 14.7S 169.4E. THE SYSTEM IS MOVING SOUTHWESTWARD AT 05 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.1S 169.0E, IS NOW LOCATED NEAR 14.7S 169.4E, APPROXIMATELY 195 NM NORTH- NORTHEAST OF PORT VILA, VANUATU. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS IMPROVED CONSOLIDATION WITH A DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) AND CONVECTIVE BANDING WEST WRAPPING INTO THE NORTH QUADRANT. A 180249Z AMSU IMAGE DEPICTS DEEP, CURVED CONVECTIVE BANDING ALONG THE NORTHWEST QUADRANT WITH WEAKER BANDING NORTH AND NORTHEAST OF THE CENTER. A 172144Z ASCAT IMAGE SHOWS AN ELONGATED BUT DEFINED CIRCULATION WITH 25-30 KNOT WINDS; OVERALL, THE CIRCULATION HAS SLOWLY STRENGTHENED OVER THE PAST 24 HOURS. THE LLCC IS LOCATED UNDER AN UPPER-LEVEL ANTICYCLONE WITH GOOD EQUATORWARD AND POLEWARD OUTFLOW. POLEWARD OUTFLOW HAS IMPROVED AND IS BEING ENHANCED BY AN UPPER-LEVEL LOW NEAR 23S 153E (EAST COAST OF AUSTRALIA) AND UPPER-LEVEL WESTERLIES SOUTH OF THE SYSTEM. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. BASED ON THE FAVORABLE ENVIRONMENT AND EXCELLENT OUTFLOW, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS GOOD. ========================================================================= WTPS31 PGTW 20110218 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (SEVENTEEN) WARNING NR 001// REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/180521ZFEB2011// AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. TROPICAL CYCLONE 17P (SEVENTEEN) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 181800Z --- NEAR 15.4S 169.4E MOVEMENT PAST SIX HOURS - 205 DEGREES AT 02 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: 15.4S 169.4E --- FORECASTS: 12 HRS, VALID AT: 190600Z --- 15.8S 169.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 190 DEG/ 03 KTS --- 24 HRS, VALID AT: 191800Z --- 16.4S 169.1E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 170 DEG/ 04 KTS --- 36 HRS, VALID AT: 200600Z --- 17.1S 169.2E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 150 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 201800Z --- 18.1S 169.8E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 145 DEG/ 08 KTS --- 72 HRS, VALID AT: 211800Z --- 20.6S 171.6E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 140 DEG/ 14 KTS --- LONG RANGE OUTLOOK: NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY NEAR 20 KT EACH DAY. --- 96 HRS, VALID AT: 221800Z --- 24.8S 175.5E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 140 DEG/ 22 KTS --- 120 HRS, VALID AT: 231800Z --- 31.3S 177.6W MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL --- REMARKS: 182100Z POSITION NEAR 15.5S 169.4E. TROPICAL CYCLONE (TC) 17S, LOCATED APPROXIMATELY 485 NM WEST- NORTHWEST OF NADI, FIJI, HAS TRACKED SOUTH-SOUTHWESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED IMAGERY SHOWS THAT DEEP CONVECTION HAS FORMED OVER THE CENTER OF THE LOW LEVEL CIRCULATION CENTER (LLCC) AND FORMATIVE BANDING IS NOW WRAPPING INTO THE CENTER FROM THE WEST AND NORTH SIDES. AN 181753Z TRMM PASS SHOWS DEEP CURVED CONVECTION SLIGHTLY DISPLACED TO THE NORTHWEST OF THE WELL DEFINED, SYMMETRIC LOW LEVEL CIRCULATION. ENVIRONMENTAL ANALYSIS INDICATES THAT THE SYSTEM IS BENEATH AN UPPER LEVEL OUTFLOW SOURCE, IN A REGION OF LOW (15KTS) VERTICAL WIND SHEAR AND FAVORABLE SEA SURFACE TEMPERATURES. THE SYSTEM IS CURRENTLY IN A WEAK STEERING ENVIRONMENT BETWEEN TWO LOW TO MID-LEVEL SUBTROPICAL RIDGES (STR) (ONE TO THE NORTHEAST AND ONE TO THE SOUTHWEST). AN APPROACHING HIGH AMPLITUDE MIDLATITUDE TROUGH WILL START TO ERODE THE STR TO THE SOUTHWEST, ALLOWING THE SECOND STR TO THE NORTHEAST TO TAKE OVER AS THE PRIMARY STEERING MECHANISM. AROUND TAU 48, THE SYSTEM WILL BEGIN TO ACCELERATE TO THE SOUTHEAST AHEAD OF THE PASSING TROUGH. WHILE AHEAD OF THE PASSING TROUGH, POLEWARD OUTFLOW IS EXPECTED TO IMPROVE SUBSTANTIALLY, AND THE SYSTEM IS EXPECTED TO STEADILY INTENSIFY THROUGH THIS PERIOD UNTIL IS CROSSES INTO COOLER WATERS BY TAU 108. BY TAU 120 THE SYSTEM IS EXPECTED TO BEGIN EXTRATROPICAL TRANSITION UNDER THE INFLUENCES OF INCREASING VERTICAL WIND SHEAR, ENTRAINMENT OF DRIER AIR FROM A MID-LATITUDE AIRMASS TO THE SOUTH, AND PASSAGE OVER COOLER WATER. NOGAPS, GFS AND GFDN ARE ALL IN EXCELLENT AGREEMENT, AND THE FORECAST IS BASED THESE MODELS. THIS WARNING SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 180521Z FEB 11 TROPICAL CYCLONE FORMATION ALERT (WTPS22 PGTW 180530) MAXIMUM SIGNIFICANT WAVE HEIGHT AT 181800Z IS 12 FEET. NEXT WARNINGS AT 190900Z AND 192100Z. ========================================================================= WTPS31 PGTW 20110219 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 002// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 002 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 190600Z --- NEAR 16.2S 169.0E MOVEMENT PAST SIX HOURS - 225 DEGREES AT 04 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 050 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT REPEAT POSIT: 16.2S 169.0E --- FORECASTS: 12 HRS, VALID AT: 191800Z --- 16.9S 168.8E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 190 DEG/ 03 KTS --- 24 HRS, VALID AT: 200600Z --- 17.5S 168.7E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 015 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 170 DEG/ 06 KTS --- 36 HRS, VALID AT: 201800Z --- 18.6S 168.9E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 150 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 210600Z --- 19.6S 169.5E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 145 DEG/ 08 KTS --- 72 HRS, VALID AT: 220600Z --- 22.1S 171.4E MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 140 DEG/ 16 KTS --- LONG RANGE OUTLOOK: NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY NEAR 20 KT EACH DAY. --- 96 HRS, VALID AT: 230600Z --- 27.2S 175.9E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL VECTOR TO 120 HR POSIT: 135 DEG/ 26 KTS --- 120 HRS, VALID AT: 240600Z --- 34.5S 175.5W MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 190900Z POSITION NEAR 16.4S 169.0E. TROPICAL CYCLONE (TC) 17S (ATU), LOCATED APPROXIMATELY 100 NM WEST- NORTHWEST OF PORT VILLA HAS TRACKED SOUTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ATU HAS INTENSIFIED 15 KNOTS SINCE YESTERDAY AND IS BEGINNING TO SHOW SIGNS OF A DEVELOPING EYE IN MULTISPECTRAL SATELLITE IMAGERY (MSI). THE INTENSITY FORECAST HAS BEEN ADJUSTED UPWARD TO ACCOUNT FOR THIS DEVELOPMENT. THE CURRENT FORECAST INTENSITY IS BASED ON DVORAK FIXES FROM PGTW, PHFO, AND NFFN, WHICH ALL ASSIGN A 3.0 T-NUMBER. THE POSITION IS BASED ON CONSERVATIVE CLOUD FEATURES IN MSI WITH FAIR CONFIDENCE. THE STEERING FLOW REMAINS WEAK, ACCOUNTING FOR NEAR QUASISTATIONARY MOTION. THE DEEP LAYER SUBTROPICAL RIDGE IS FORECAST TO STRENGTHEN TO THE EAST AND BECOME THE PRIMARY STEERING MECHANISM AFTER 36 HOURS. THE CYCLONE WILL TRACK POLEWARD ALONG ITS WESTERN PERIPHERY. AN UPPER LEVEL TROUGH WILL DEEPEN AND DIG INTO THE SUB-TROPICS BY DAY 4 OF THE FORECAST AND WILL ACCOUNT FOR MARKED SOUTHEASTWARD ACCELERATION. AROUND THIS TIME SEA SURFACE TEMPERATURES WILL COOL AND VERTICAL WIND SHEAR WILL ELEVATE, INITIATING EXTRATROPICAL TRANSITION. BY TAU 120 THE SYSTEM WILL HAVE LOST MOST OF ITS TROPICAL CHARACTERISTICS AS IT INTERACTS WITH A BAROCLINIC BOUNDARY NEAR NORTHERN NEW ZEALAND. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 190600Z IS 16 FEET. NEXT WARNINGS AT 192100Z AND 200900Z.// ========================================================================= WTPS31 PGTW 20110219 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 191800Z --- NEAR 16.7S 169.1E MOVEMENT PAST SIX HOURS - 160 DEGREES AT 03 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 - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT REPEAT POSIT: 16.7S 169.1E --- FORECASTS: 12 HRS, VALID AT: 200600Z --- 17.0S 169.2E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 170 DEG/ 03 KTS --- 24 HRS, VALID AT: 201800Z --- 17.5S 169.3E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 015 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 170 DEG/ 05 KTS --- 36 HRS, VALID AT: 210600Z --- 18.4S 169.5E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 165 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 211800Z --- 19.9S 169.9E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 155 DEG/ 11 KTS --- 72 HRS, VALID AT: 221800Z --- 23.8S 171.7E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 140 DEG/ 22 KTS --- LONG RANGE OUTLOOK: NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY NEAR 20 KT EACH DAY. --- 96 HRS, VALID AT: 231800Z --- 30.7S 178.1E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 192100Z POSITION NEAR 16.8S 169.1E. TROPICAL CYCLONE (TC) 17S, LOCATED APPROXIMATELY 485 NM WEST OF NADI, FIJI, HAS TRACKED SOUTH-SOUTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS TIGHTLY CURVED CONVECTIVE BANDING WRAPPING INTO A WELL-DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CENTRAL CONVECTION. A 191731Z SSMI MICROWAVE IMAGE DEPICTS A SYMMETRIC MICROWAVE EYE WITH A CONCENTRIC EYE-WALL AND CONFIRMS THE CURRENT POSITION WITH GOOD CONFIDENCE. ENVIRONMENTAL ANALYSIS INDICATES THAT THE SYSTEM IS LOCATED BENEATH AN UPPER LEVEL OUTFLOW SOURCE, IN A REGION OF MODERATE VERTICAL WIND SHEAR (20 TO 25 KNOTS) AND FAVORABLE SEA SURFACE TEMPERATURES. ANIMATED WATER VAPOR IMAGERY SHOWS EXCELLENT EQUATORWARD AND EASTWARD OUTFLOW, HOWEVER POLEWARD OUTFLOW IS SOMEWHAT HINDERED DUE TO SUBSIDENCE ASSOCIATED WITH A PASSING SHORT-WAVE MID-LATITUDE TROUGH. TC 17S IS CURRENTLY IN A WEAK STEERING ENVIRONMENT BETWEEN TWO DEEP-LAYERED SUBTROPICAL RIDGES (STR) WHICH WILL CAUSE GENERALLY SLOW AND SOUTH-SOUTHEASTERLY MOVEMENT THROUGH TAU 36. AS AN APPROACHING HIGH-AMPLITUDE MID-LATITUDE TROUGH WEAKENS THE STR TO THE SOUTHWEST, THE STR TO THE NORTHEAST WILL BECOME THE DOMINATE STEERING RIDGE AND THE SYSTEM WILL BEGIN TO ACCELERATE AHEAD OF THE PASSING TROUGH. POLEWARD OUTFLOW IS EXPECTED TO IMPROVE AHEAD OF THE PASSING TROUGH, ALLOWING THE SYSTEM TO STEADILY INTENSIFY, WHILE IT CONTINUES TO TRACK OVER FAVORABLE SSTS UNTIL AROUND 28 DEGREES SOUTH LATITUDE. TC ATU IS FORECAST TO BEGIN INTERACTION WITH THE MID-LATITUDE WESTERLIES BY TAU 96, AND COMPLETE EXTRA-TROPICAL TRANSITION AS A STORM FORCE LOW BY TAU 120. NUMERICAL MODEL GUIDANCE IS SLIGHTLY SPREAD IN THE EARLY TAUS, DUE TO THE WEAK STEERING PATTERN, BUT BECOME TIGHTLY CLUSTERED AS THE HIGH AMPLITUDE TROUGH PUSHES THROUGH IN THE LATER TAUS. THIS FORECAST IS SLIGHTLY EAST OF CONSENSUS TO ACCOUNT FOR WBAR, WHICH APPEARS TO BE MIS-ANALYZING THE TIMING AND STRENGTH OF THE HIGH-AMPLITUDE TROUGH PATTERN, BUT REMAINS WITHIN THE DYNAMIC AIDS ENVELOPE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 191800Z IS 19 FEET. NEXT WARNINGS AT 200900Z AND 202100Z.// ========================================================================= WTPS31 PGTW 20110220 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 004 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 200600Z --- NEAR 17.0S 169.6E MOVEMENT PAST SIX HOURS - 120 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT REPEAT POSIT: 17.0S 169.6E --- FORECASTS: 12 HRS, VALID AT: 201800Z --- 17.5S 170.1E MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 155 DEG/ 04 KTS --- 24 HRS, VALID AT: 210600Z --- 18.3S 170.5E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT 145 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 135 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 160 DEG/ 09 KTS --- 36 HRS, VALID AT: 211800Z --- 20.0S 171.1E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 145 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 165 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 220600Z --- 21.5S 171.6E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT 145 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 135 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 150 DEG/ 15 KTS --- 72 HRS, VALID AT: 230600Z --- 26.8S 175.1E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT 135 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 140 DEG/ 26 KTS --- LONG RANGE OUTLOOK: NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY NEAR 20 KT EACH DAY. --- 96 HRS, VALID AT: 240600Z --- 34.4S 176.8W MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 200900Z POSITION NEAR 17.1S 169.7E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 455 NM WEST OF NADI, FIJI, HAS TRACKED EAST-SOUTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. THE SYSTEM HAS STRENGTHENED TO 90 KNOTS SINCE YESTERDAY BASED ON 06Z DVORAK ESTIMATES FROM PGTW, PHFO, AND NFFN RANGING FROM OF T4.5 TO T5.0. THE PEAK INTENSITY HAS BEEN ADJUSTED UPWARD ON ACCOUNT OF THE CURRENT INTENSITY. AN EMBEDDED CENTER WITHIN A LARGE CENTRAL DENSE OVERCAST HAS AIDED IN POSITIONING. THE DEEP LAYER SUBTROPICAL RIDGE TO THE EAST OF TC ATU CONTINUES TO STRENGTHEN AND WILL BECOME THE MAIN STEERING MECHANISM FOR THE DURATION OF THE FORECAST. SLOW TO STEADY INTENSIFICATION IS LIKELY OVER THE NEXT 2 DAYS DUE TO LOW VERTICAL WIND SHEAR, STRONG RADIAL OUTFLOW ALOFT, AND WARM WATERS. AFTER TAU 48 ATU WILL BEGIN TO WEAKEN AS SEA SURFACE TEMPERATURES COOL AND VERTICAL WIND SHEAR ELEVATES IN ADVANCE OF AN UPPER LEVEL TROUGH. THIS TROUGH WILL ALSO INCITE POLEWARD ACCELERATION. AN ACCOMPANYING BAROCLINIC ZONE WILL INITIATE EXTRATROPICAL TRANSITION NEAR TAU 72 AND BY TAU 96, THE LAST FORECAST POSITION, THE SYSTEM WILL BE FULLY EXTRATROPICAL. MODEL GUIDANCE IS IN EXCEPTIONAL AGREEMENT REGARDING TRACK. AS SUCH THE FORECAST LIES CLOSE TO THE MODEL CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 200600Z IS 23 FEET. NEXT WARNINGS AT 202100Z AND 210900Z.// ========================================================================= WTPS31 PGTW 20110220 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 201800Z --- NEAR 17.4S 169.7E MOVEMENT PAST SIX HOURS - 150 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT REPEAT POSIT: 17.4S 169.7E --- FORECASTS: 12 HRS, VALID AT: 210600Z --- 18.4S 170.1E MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 155 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 160 DEG/ 08 KTS --- 24 HRS, VALID AT: 211800Z --- 19.9S 170.7E MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 155 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 160 DEG/ 12 KTS --- 36 HRS, VALID AT: 220600Z --- 22.2S 171.5E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 155 DEG/ 17 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 221800Z --- 25.3S 173.1E MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 140 DEG/ 21 KTS --- 72 HRS, VALID AT: 231800Z --- 31.4S 179.6E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 145 DEG/ 26 KTS --- LONG RANGE OUTLOOK: NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY NEAR 20 KT EACH DAY. --- 96 HRS, VALID AT: 241800Z --- 39.9S 173.0W MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 202100Z POSITION NEAR 17.7S 169.8E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 80 NM EAST- NORTHEAST OF PORT VILA, VANUATU, HAS TRACKED SOUTH-SOUTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. RECENT DVORAK T-NUMBER ESTIMATES OF 6.0 FROM PGTW, PHFO, AND KNES INDICATE THAT THE MAXIMUM SUSTAINED SURFACE WIND ASSOCIATED WITH THE CYCLONE HAS INCREASED TO AN ESTIMATED 115 KNOTS. RECENT ANIMATED INFRARED SATELLITE IMAGERY INDICATES FORMATION OF A 22 NM BANDING EYE FEATURE, ALSO EVIDENT IN RECENT MICROWAVE SATELLITE IMAGERY. TC 17P IS TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE TO THE EAST. THIS RIDGE WILL CONTINUE TO BUILD OVER THE NEXT FEW DAYS TO THE NORTHWEST OF THE CYCLONE, STEERING THE SYSTEM GENERALLY SOUTH-SOUTHEASTWARD THROUGH THE FORECAST PERIOD. AS A MID-LATITUDE TROUGH APPROACHES FROM THE SOUTHWEST, TC 17P WILL ACCELERATE TOWARD THE BAROCLINIC ZONE, PARTICULARLY AFTER TAU 36. BY TAU 72, INCREASING VERTICAL WIND SHEAR AHEAD OF THE APPROACHING TROUGH, ENTRAINMENT OF DRIER AIR, AND PASSAGE OVER A COOLER SEA SURFACE WILL INDUCE THE FIRST PHASE OF EXTRATROPICAL TRANSITION. BY TAU 96 THE CYCLONE IS EXPECTED TO BE FULLY EXTRATROPICAL, THROUGH STILL QUITE INTENSE DUE TO FAVORABLE INTERACTION WITH THE MID-LATITUDE UPPER-LEVEL FLOW PATTERN. THE NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH THE CURRENT FORECAST, WHICH LIES SLIGHTLY EAST OF AND FASTER THAN THE MODEL CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 201800Z IS 31 FEET. NEXT WARNINGS AT 210900Z AND 212100Z.// ========================================================================= WTPS31 PGTW 20110221 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 006// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 006 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 210600Z --- NEAR 18.4S 170.3E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 095 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 175 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 155 NM NORTHWEST QUADRANT REPEAT POSIT: 18.4S 170.3E --- FORECASTS: 12 HRS, VALID AT: 211800Z --- 20.1S 171.0E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 155 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 160 DEG/ 12 KTS --- 24 HRS, VALID AT: 220600Z --- 22.4S 171.9E MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 155 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 160 DEG/ 16 KTS --- 36 HRS, VALID AT: 221800Z --- 25.3S 173.2E MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 085 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 145 DEG/ 23 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 230600Z --- 29.1S 176.2E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 135 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 140 DEG/ 25 KTS --- 72 HRS, VALID AT: 240600Z --- 36.7S 176.0W MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 210900Z POSITION NEAR 18.8S 170.5E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 115 NM EAST- SOUTHEAST OF PORT VILA, VANUATU, HAS TRACKED SOUTHEASTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER WITH A BANDING EYE SUPPORTING THE CURRENT POSITION AND MOTION WITH HIGH CONFIDENCE. OVER THE PAST 12 HOURS, THE SYSTEM HAS MAINTAINED A SIMILAR STRUCTURE ON MICROWAVE IMAGERY (COMPARING THE 210549Z ========================================================================= WTPS31 PGTW 20110221 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 007// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 007 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 211800Z --- NEAR 19.9S 171.1E MOVEMENT PAST SIX HOURS - 150 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 175 NM NORTHEAST QUADRANT 185 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 155 NM NORTHWEST QUADRANT REPEAT POSIT: 19.9S 171.1E --- FORECASTS: 12 HRS, VALID AT: 220600Z --- 22.1S 172.0E MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 155 DEG/ 17 KTS --- 24 HRS, VALID AT: 221800Z --- 25.1S 173.6E MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 110 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 170 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 145 DEG/ 21 KTS --- 36 HRS, VALID AT: 230600Z --- 28.4S 176.4E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 185 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 135 DEG/ 24 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 231800Z --- 31.8S 179.8W MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 135 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 145 DEG/ 24 KTS --- 72 HRS, VALID AT: 241800Z --- 39.1S 172.4W MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 212100Z POSITION NEAR 20.5S 171.3E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 295 NM EAST- NORTHEAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION ESTIMATE IS BASED ON SATELLITE FIXES FROM VARIOUS REPORTING AGENCIES AND A 211701Z SSMI IMAGE. THE CURRENT INTENSITY OF 95 KNOTS IS CONSISTENT WITH DVORAK INTENSITY T-NUMBER ESTIMATES RANGING FROM 90 TO 102 KNOTS. TC 17P HAS UNDERGONE SOME STRUCTURAL CHANGE OVER THE PAST TWELVE HOURS, WITH EROSION OF THE SOUTHWESTERN PORTION OF THE EYEWALL NOW EVIDENT IN INFRARED SATELLITE IMAGERY. THESE STRUCTURAL CHANGES HAVE RESULTED IN SLIGHT WEAKENING. HOWEVER, THE CYCLONE IS EXPECTED TO MAINTAIN INTENSITY OR INTENSIFY A BIT OVER THE UPCOMING 24 HOURS AS STRONG UPPER LEVEL OUTFLOW AND PASSAGE OVER A WARM SEA SURFACE ARREST THE CURRENT WEAKENING TREND. TC 17P IS TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE TO THE EAST AND IS EXPECTED TO ACCELERATE DURING THE FORECAST PERIOD AHEAD OF A MID-LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST. INCREASING VERTICAL WIND SHEAR, ENTRAINMENT OF DRIER AIR, AND PASSAGE OVER COOLER WATER WILL INDUCE THE FIRST PHASE OF EXTRATROPICAL TRANSITION BY TAU 36. FAVORABLE INTERACTION WITH THE UPPER LEVEL FLOW PATTERN AHEAD OF THE APPROACHING TROUGH WILL ENABLE TC 17P TO TRANSITION INTO A STRONG EXTRATROPICAL LOW BY TAU 72. THE NUMERICAL MODEL GUIDANCE REMAINS IN VERY GOOD AGREEMENT. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 211800Z IS 33 FEET. NEXT WARNINGS AT 220900Z AND 222100Z.// ========================================================================= WTPS31 PGTW 20110222 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 008// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 008 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 220600Z --- NEAR 22.7S 172.1E MOVEMENT PAST SIX HOURS - 170 DEGREES AT 15 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 100 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 175 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 165 NM NORTHWEST QUADRANT REPEAT POSIT: 22.7S 172.1E --- FORECASTS: 12 HRS, VALID AT: 221800Z --- 25.6S 173.7E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 180 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 155 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 145 DEG/ 19 KTS --- 24 HRS, VALID AT: 230600Z --- 28.6S 176.3E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 145 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 140 DEG/ 23 KTS --- 36 HRS, VALID AT: 231800Z --- 32.0S 180.0E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 155 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 135 DEG/ 27 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 240600Z --- 35.8S 175.5W MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 220900Z POSITION NEAR 23.4S 172.5E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 315 NM EAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHWARD AT 15 KNOTS OVER THE PAST SIX HOURS. THERE IS HIGH CONFIDENCE IN THE CURRENT POSITION AND MOTION BASED ON THE 35-NM EYE EVIDENT IN VISIBLE IMAGERY. THE CURRENT INTENSITY OF 95 KNOTS IS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES RANGING FROM 90 TO 102 KNOTS. TC 17P HAS MAINTAINED INTENSITY OVER THE PAST 06 HOURS WITH LITTLE STRUCTURAL CHANGE. A 220532Z SSMI IMAGE DEPICTS STRONG CONVECTIVE BANDING OVER ALL QUADRANTS. TC 17P IS ACCELERATING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE TO THE EAST AND IS EXPECTED TO TRACK SOUTHEASTWARD THROUGH THE FORECAST PERIOD. TC 17P SHOULD BEGIN EXTRA- TROPICAL TRANSITION (ETT) NEAR TAU 24 AS IT BEGINS TO INTERACT WITH A MID-LATITUDE TROUGH APPROACHING FROM THE SOUTHWEST. INCREASING VERTICAL WIND SHEAR, ENTRAINMENT OF DRIER AIR, AND PASSAGE OVER COOLER WATER WILL RESULT IN RAPID WEAKENING AFTER TAU 24. THE SYSTEM IS EXPECTED TO COMPLETE ETT BY TAU 48 AND SHOULD REMAIN A STRONG EXTRATROPICAL LOW. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 220600Z IS 35 FEET. NEXT WARNINGS AT 222100Z AND 230900Z.// ========================================================================= WTPS31 PGTW 20110222 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 009// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 009 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 221800Z --- NEAR 25.4S 173.7E MOVEMENT PAST SIX HOURS - 150 DEGREES AT 17 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 180 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 155 NM NORTHWEST QUADRANT REPEAT POSIT: 25.4S 173.7E --- FORECASTS: 12 HRS, VALID AT: 230600Z --- 28.7S 176.1E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 180 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 155 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 135 DEG/ 20 KTS --- 24 HRS, VALID AT: 231800Z --- 31.4S 179.6E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 135 DEG/ 20 KTS --- 36 HRS, VALID AT: 240600Z --- 34.1S 176.9W MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 222100Z POSITION NEAR 26.2S 174.3E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 500 NM SOUTH- SOUTHWEST OF NADI, FIJI, HAS TRACKED SOUTH-SOUTHEASTWARD AT 17 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS A 14 NM EYE WITH DEGRADED CONVECTION ALONG THE SOUTHWESTERN PERIPHERY. A 221644Z SSMI IMAGES DEPICTS DEEP CONVECTIVE BANDING HAS DECREASED ALONG THE NORTHWEST QUADRANT DUE TO SUBSIDENCE ALOFT. OUTFLOW IS ALSO HINDERED ON THIS SIDE ALTHOUGH POLEWARD OUTFLOW REMAINS GOOD. THE CURRENT INTENSITY IS BASED ON AN AVERAGE OF PGTW, PHFO, AND NFFN DVORAK ESTIMATES RANGING FROM 77 TO 102 KNOTS. TC 17P IS ACCELERATING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE AND WILL CONTINUE TRACKING OVER COOLER WATERS (BELOW 26 DEGREES CELSIUS) DURING THE NEXT 12 HOURS. DUE TO THE COOLER WATERS COUPLED WITH INCREASED VERTICAL WIND SHEAR ASSOCIATED WITH THE MID-LATITUDE TROUGH TO THE SOUTHWEST, TC 17P WILL WEAKEN AND TRANSITION INTO A STRONG EXTRA-TROPICAL LOW BY TAU 36. NUMERICAL MODEL GUIDANCE IS IN EXCELLENT AGREEMENT. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221800Z IS 33 FEET. NEXT WARNINGS AT 230900Z AND 232100Z.// ========================================================================= WTPS31 PGTW 20110223 09:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 010// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 010 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 230600Z --- NEAR 28.5S 176.5E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 22 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE AND RADAR PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT REPEAT POSIT: 28.5S 176.5E --- FORECASTS: 12 HRS, VALID AT: 231800Z --- 31.4S 179.6W MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 135 NM NORTHEAST QUADRANT 145 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 130 DEG/ 23 KTS --- 24 HRS, VALID AT: 240600Z --- 34.2S 175.3W MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 230900Z POSITION NEAR 29.2S 177.5E. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 505 NM NORTH-NORTHEAST OF AUCKLAND, NEW ZEALAND, HAS ACCELERATED SOUTHEASTWARD AT 22 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY AND A 230515Z 85H SSMI MICROWAVE IMAGE DEPICT A 14 NM RAGGED EYE WITH EXPOSED LOW LEVEL BANDING ALONG THE NORTHWESTERN QUADRANT AND WEAKENING DEEP CONVECTION EXTENDING INTO THE SOUTHERN QUADRANTS (INDICATIVE OF THE ONSET OF EXTRA-TROPICAL TRANSITION). THE CURRENT INTENSITY IS BASED ON DVORAK FINAL-T AND CURRENT INTENSITY ESTIMATES RANGING FROM 65 TO 77 KNOTS FROM PGTW AND KNES. TC 17P IS CURRENTLY UNDERGOING EXTRA-TROPICAL TRANSITION (ET) AND IS EXPECTED TO COMPLETE ET BY 24/06Z AS IT CONTINUES TO ACCELERATE ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE INTO THE MID-LATITUDE WESTERLIES. TC 17P WILL SLOWLY WEAKEN AS IT ENCOUNTERS INCREASED VERTICAL WIND SHEAR AND COOLER SSTS, BUT SHOULD COMPLETE ET AS A STRONG EXTRA-TROPICAL LOW. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 230600Z IS 30 FEET. NEXT WARNINGS AT 232100Z.// ========================================================================= WTPS31 PGTW 20110223 21:00z MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/TROPICAL CYCLONE 17P (ATU) WARNING NR 011// RMKS/ 1. TROPICAL CYCLONE 17P (ATU) WARNING NR 011 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 231800Z --- NEAR 31.4S 179.9E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 22 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 BECOMING EXTRATROPICAL 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 - 120 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT REPEAT POSIT: 31.4S 179.9E --- FORECASTS: 12 HRS, VALID AT: 240600Z --- 33.7S 175.6W MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 232100Z POSITION NEAR 32.0S 179.0W. TROPICAL CYCLONE (TC) 17P (ATU), LOCATED APPROXIMATELY 415 NM NORTHEAST OF AUCKLAND, NEW ZEALAND, HAS TRACKED SOUTHEASTWARD AT 22 KNOTS OVER THE PAST SIX HOURS. ANIMATED WATER VAPOR IMAGERY SHOWS THE SYSTEM HAS SIGNIFICANTLY ACCELERATED AND IS NOW EMBEDDED IN THE UPPER LEVEL WESTERLIES. ADDITIONALLY, THE LOW LEVEL CIRCULATION CENTER IS SHEARED TO THE WEST OF THE MAIN CONVECTION. COLD AIR ADVECTION IS EVIDENT ON THE SOUTHWEST FLANK WITH LINES OF STRATO- CUMULUS CLOUDS ADVANCING INTO THE LLCC. THE SYSTEM IS BEGINNING TO EXHIBIT EXTRA-TROPICAL (ET) CHARACTERISTICS AND IS EXPECTED TO BECOME FULL ET IN 12 APPROXIMATELY HOURS. THIS IS SUPPORTED BY ET PROGNOSTIC MODELS. 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 231800Z IS 27 FEET.//
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
Document: tropical_cyclone_atu_jtwc_advisories.htm
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