Tropical Cyclones
[Index] | Tropical Cyclone ALESSIA : JTWC Advisories |
Season 2013-2014 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
---> Tropical Cyclone ALESSIA Track Map and Data |
WTXS21 PGTW 20131121 23:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 170 NM EITHER SIDE OF A LINE FROM 13.5S 117.5E TO 14.0S 123.8E 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 212130Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 13.6S 118.2E. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 08 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 13.6S 118.2E, IS NOW LOCATED NEAR 13.7S 118.5E, APPROXIMATELY 330 NM NORTHWEST OF BROOME, AUSTRALIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION OVER A DEVELOPING LOW LEVEL CIRCULATION CENTER (LLCC). A RECENT 211400Z METOP-B 89 GHZ MICROWAVE PASS SHOWS THE LLCC HAS BECOME MORE SYMMETRIC OVER THE PAST 24 HOURS, BUT INDICATES DEEP CONVECTION REMAINS ALONG THE SOUTHERN PERIPHERY UNDER THE INFLUENCE OF MODERATE LEVELS OF VERTICAL WIND SHEAR (15 TO 20 KNOTS). SEA SURFACE TEMPERATURES ARE FAVORABLE FOR DEVELOPMENT, RANGING FROM 29 TO 31 DEGREES CELSIUS. MOST MODELS MAINTAIN A WEAK CIRCULATION, WHICH TRAVERSES NORTHERN AUSTRALIA OVER THE NEXT SEVERAL DAYS BUT DO NOT INDICATE STRONG DEVELOPMENT IN THE NEAR-TERM. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 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 222300Z.// ========================================================================= WTXS31 PGTW 20131122 09:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (TWO) WARNING NR 001// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/212251ZNOV2013// AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. TROPICAL CYCLONE 02S (TWO) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 220600Z --- NEAR 14.5S 120.1E MOVEMENT PAST SIX HOURS - 120 DEGREES AT 14 KTS POSITION ACCURATE TO WITHIN 040 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: 14.5S 120.1E --- FORECASTS: 12 HRS, VALID AT: 221800Z --- 14.7S 121.7E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 090 DEG/ 08 KTS --- 24 HRS, VALID AT: 230600Z --- 14.7S 123.4E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 080 DEG/ 09 KTS --- 36 HRS, VALID AT: 231800Z --- 14.3S 125.3E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 080 DEG/ 10 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 240600Z --- 13.9S 127.3E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 72 HR POSIT: 085 DEG/ 08 KTS --- 72 HRS, VALID AT: 250600Z --- 13.5S 130.7E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 96 HR POSIT: 100 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 260600Z --- 13.9S 133.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 120 HR POSIT: 135 DEG/ 04 KTS --- 120 HRS, VALID AT: 270600Z --- 15.1S 135.1E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 220900Z POSITION NEAR 14.5S 120.5E. TROPICAL CYCLONE 02S (TWO), LOCATED APPROXIMATELY 237 NM NORTH- NORTHWESTWARD OF BROOME, AUSTRALIA, HAS TRACKED EAST-SOUTHEASTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS SIGNIFICANTLY DEEPENED AS FORMATIVE BANDS WRAPPED TIGHTER INTO THE LOW LEVEL CIRCULATION CENTER THAT HAS BECOME BETTER-DEFINED. THE INITIAL POSITION AND INTENSITY ARE BASED ON CLOSELY-SPACED DVORAK FIXES FROM PGTW, APRF, AND KNES. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS UNDER THE RIDGE AXIS IN AN AREA OF LOW (05-10 KNOT) VERTICAL WIND SHEAR AND GOOD RADIAL OUTFLOW. THE CYCLONE IS TRACKING ALONG THE OUTER BOUNDARY OF A NEAR-EQUATORIAL RIDGE TO THE NORTHEAST AND IS EXPECTED TO MOVE ON A GENERALLY EASTWARD PATTERN TOWARDS DARWIN. THE SYSTEM WILL CONTINUE TO INTENSIFY OVER THE NEXT 36 HOURS AS UPPER LEVEL CONDITIONS, IN ADDITION TO WARM SEA SURFACE TEMPERATURES, PREVAIL. AFTERWARDS, THE CYCLONE WILL DRAG ACROSS THE SWAMPY TERRAIN OF NORTHERN AUSTRALIA JUST SOUTH OF DARWIN. INTERACTION WITH THE LANDMASS WILL CAUSE ITS GRADUAL DECAY AND EVENTUAL DISSIPATION BY TAU 120. THE AVAILABLE NUMERIC GUIDANCE IS IN FAIR AGREEMENT; HOWEVER, GIVEN THE UNCERTAINTY OF AN OVER LAND TRACK, THERE IS LOW CONFIDENCE IN THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 220600Z IS 10 FEET. NEXT WARNINGS AT 222100Z AND 230900Z. THIS WARNING SUPERSEDES AND CANCELS REF A (WTXS21 PGTW 212300). // ========================================================================= WTXS31 PGTW 20131122 21:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 002// RMKS/ 1. TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 002 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 221800Z --- NEAR 14.7S 122.8E MOVEMENT PAST SIX HOURS - 100 DEGREES AT 12 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT REPEAT POSIT: 14.7S 122.8E --- FORECASTS: 12 HRS, VALID AT: 230600Z --- 14.7S 124.4E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 080 DEG/ 09 KTS --- 24 HRS, VALID AT: 231800Z --- 14.3S 126.3E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 080 DEG/ 10 KTS --- 36 HRS, VALID AT: 240600Z --- 13.9S 128.3E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 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 48 HR POSIT: 085 DEG/ 09 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 241800Z --- 13.7S 130.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 100 DEG/ 06 KTS --- 72 HRS, VALID AT: 251800Z --- 14.0S 132.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 96 HR POSIT: 105 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 261800Z --- 14.6S 134.6E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 222100Z POSITION NEAR 14.7S 123.2E. TROPICAL CYCLONE (TC) 02S (ALESSIA), LOCATED APPROXIMATELY 490 NM WEST-SOUTHWESTWARD OF DARWIN, AUSTRALIA, HAS TRACKED EASTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH A COMPACT AREA OF DEEP CONVECTION PERSISTING OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC). A PARTIAL 221513Z TRMM 37 GHZ IMAGE AND A PARTIAL 221837Z AMSU-B 89 GHZ IMAGE DEPICT CURVED CONVECTIVE BANDING WRAPPING INTO THE CENTER, PROVIDING GOOD CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS BASED ON CURRENT INTENSITY ESTIMATES OF 45 KNOTS FROM ALL AGENCIES. TC 02S IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE NEAR-EQUATORIAL RIDGE AND IS FORECAST TO CONTINUE TRACKING GENERALLY EASTWARD THROUGH THE FORECAST PERIOD. TC 02S IS EXPECTED TO SKIRT THE NORTHERN COAST OF AUSTRALIA THROUGH TAU 36 AND WILL MAKE LANDFALL NEAR TAU 48. TC ALESSIA IS EXPECTED TO INTENSIFY SLIGHTLY TO A PEAK OF 50 KNOTS BY TAU 12 BUT SHOULD WEAKEN THEREAFTER DUE TO LAND INTERACTION AND DRY AIR INTRUSION. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT BUT DIFFER ON THE STRENGTH AND TIMING OF A DEVELOPING HIGH OVER EASTERN AUSTRALIA, WHICH WILL ACT TO SLOW THE SYSTEM AND TURN IT EQUATORWARD. THE JTWC FORECAST FAVORS THE GFS AND ECMWF SOLUTIONS, WHICH INDICATE A TURN SOUTHWARD NEAR THE WESTERN GULF OF CARPENTARIA AFTER TAU 72. DUE TO THE DEVELOPING HIGH AND PERSISTENT LAND INTERACTION, REGENERATION OVER THE GULF OF CARPENTARIA IS UNLIKELY. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST DUE THE SHARP DIFFERENCES IN THE SOUTHWARD TRACK AFTER TAU 48. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221800Z IS 12 FEET. NEXT WARNINGS AT 230900Z AND 232100Z.// ========================================================================= WTXS31 PGTW 20131123 09:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 230600Z --- NEAR 14.9S 124.7E MOVEMENT PAST SIX HOURS - 105 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT REPEAT POSIT: 14.9S 124.7E --- FORECASTS: 12 HRS, VALID AT: 231800Z --- 14.7S 126.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 080 DEG/ 09 KTS --- 24 HRS, VALID AT: 240600Z --- 14.4S 128.3E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 36 HR POSIT: 090 DEG/ 08 KTS --- 36 HRS, VALID AT: 241800Z --- 14.4S 130.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 48 HR POSIT: 095 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 250600Z --- 14.5S 131.3E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 115 DEG/ 05 KTS --- 72 HRS, VALID AT: 260600Z --- 15.4S 133.3E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 230900Z POSITION NEAR 14.9S 125.1E. TROPICAL CYCLONE 02S (ALESSIA), LOCATED APPROXIMATELY 389 NM WEST- SOUTHWESTWARD OF DARWIN, AUSTRALIA, HAS TRACKED EAST-SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED OVERALL DEPTH AND FORMATIVE STRUCTURE AS IT IS ABOUT TO MAKE LANDFALL INTO NORTHWEST AUSTRALIA. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS BASED ON CONGRUENT DVORAK ESTIMATES FROM ALL REPORTING AGENCIES. STEERED BY THE NEAR- EQUATORIAL RIDGE, TC ALESSIA IS EXPECTED TO GRADUALLY WEAKEN AND DRAG EASTWARD INTO THE NORTHERN TERRITORY WITH A BRIEF WATER PASSAGE OVER JOSEPH BONAPARTE GULF. AFTER TAU 48, A BUILDING HIGH OVER EAST-CENTRAL AUSTRALIA WILL DEFLECT A WEAKENED 02S POLEWARD, EVENTUALLY DISSIPATING BY TAU 72. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST DUE THE SHARP DIFFERENCES IN THE NUMERIC MODELS SOUTHWARD TRACK AFTER TAU 48. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 230600Z IS 13 FEET. NEXT WARNINGS AT 232100Z AND 240900Z. // ========================================================================= WTXS31 PGTW 20131123 21:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 004 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 231800Z --- NEAR 14.0S 126.7E MOVEMENT PAST SIX HOURS - 070 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE AND SYNOPTIC DATA 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 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT REPEAT POSIT: 14.0S 126.7E --- FORECASTS: 12 HRS, VALID AT: 240600Z --- 13.7S 128.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 090 DEG/ 09 KTS --- 24 HRS, VALID AT: 241800Z --- 13.7S 130.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 36 HR POSIT: 100 DEG/ 08 KTS --- 36 HRS, VALID AT: 250600Z --- 13.9S 132.0E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 48 HR POSIT: 105 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 251800Z --- 14.3S 133.5E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 232100Z POSITION NEAR 13.9S 127.2E. TROPICAL CYCLONE (TC) 02S (ALESSIA), LOCATED APPROXIMATELY 261 NM WEST-SOUTHWEST OF DARWIN, AUSTRALIA, HAS TRACKED EAST-NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY INDICATES INCREASING DEEP CONVECTION OVER THE NORTHERN SEMI-CIRCLE OF TC 02S, WHICH IS TRACKING ALONG THE NORTHERN KIMBERLY COAST. A 231613Z GCOM IMAGE DEPICTS A CURVED DEEP CONVECTIVE BAND WRAPPING INTO THE NORTHEAST QUADRANT OF THE LOW- LEVEL CIRCULATION CENTER (LLCC). A RECENT 231418Z TRMM IMAGE SHOWING A DEFINED LLCC ALSO SUPPORTS THE CURRENT POSITION AND RECENT MOTION WITH GOOD CONFIDENCE. TC 02S TRACKED JUST SOUTH OF TROUGHTON ISLAND AND IS CURRENTLY LOCATED ABOUT 10 NM TO THE SOUTHEAST; SUSTAINED SURFACE WINDS (10-MIN AVERAGE) PEAKED AT 37 KNOTS (SOUTHWESTERLY) WITH A MINIMUM SLP OF 1001 MB REPORTED AT 23/17Z. THIS OBSERVATION ALONG WITH DVORAK INTENSITY ESTIMATES SUPPORTS THE CURRENT INTENSITY OF 40 KNOTS. TC 02S IS TRACKING ALONG THE SOUTHERN PERIPHERY OF THE NEAR-EQUATORIAL RIDGE AND IS FORECAST TO CONTINUE TRACKING GENERALLY EASTWARD THROUGH THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT BUT DIFFER ON THE STRENGTH AND TIMING OF A DEVELOPING HIGH OVER EASTERN AUSTRALIA, WHICH WILL ACT TO SLOW THE SYSTEM AND TURN IT POLEWARD. THE JTWC FORECAST FAVORS THE GFS AND ECMWF SOLUTIONS, WHICH INDICATE A TURN SOUTHWARD NEAR THE WESTERN GULF OF CARPENTARIA AFTER TAU 48. DUE TO THE DEVELOPING HIGH AND PERSISTENT LAND INTERACTION, REGENERATION OVER THE GULF OF CARPENTARIA IS UNLIKELY. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST DUE THE SHARP DIFFERENCES IN THE MODELS AFTER TAU 36. TC 02S IS EXPECTED TO WEAKEN AND DISSIPATE OVER LAND BY TAU 48. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231800Z IS 11 FEET. NEXT WARNINGS AT 240900Z AND 242100Z.// ========================================================================= WTXS31 PGTW 20131124 09:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 240600Z --- NEAR 13.8S 129.0E MOVEMENT PAST SIX HOURS - 090 DEGREES AT 15 KTS POSITION ACCURATE TO WITHIN 020 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 DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER REPEAT POSIT: 13.8S 129.0E --- FORECASTS: 12 HRS, VALID AT: 241800Z --- 13.9S 131.0E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 24 HR POSIT: 110 DEG/ 08 KTS --- 24 HRS, VALID AT: 250600Z --- 14.5S 132.6E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 240900Z POSITION NEAR 13.8S 129.5E. TROPICAL CYCLONE 02S (ALESSIA), LOCATED APPROXIMATELY 136 NM SOUTHWEST OF DARWIN, AUSTRALIA, HAS TRACKED EASTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS ACCELERATED ACROSS THE JOSEPH BONAPARTE GULF AS IT MAINTAINED SYMMETRY. HOWEVER, THE CONVECTION HAS WEAKENED AS IT APPROACHES THE NORTHERN TERRITORY SOUTH OF DARWIN TO MAKE ONE FINAL LANDFALL BEOFRE TAU 12. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS SUPPORTED BY DVORAK ESTIMATES FROM PGTW, KNES, AND APRF. TC ALESSIA IS EXPECTED TO QUICKLY DISSIPATE AFTER LANDFALL DUE TO FRICTIONAL EFFECTS. 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 240600Z IS 11 FEET. // ========================================================================= WTPS21 PGTW 20131127 03:00z 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 100 NM RADIUS OF 15.6S 137.0E 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 270230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 15.6S 137.0E. THE SYSTEM IS MOVING SOUTHWARD AT 02 KNOTS. 2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.3S 136.7E IS NOW LOCATED NEAR 15.6N 137.0E, APPROXIMATELY 185 NM SOUTH OF GOVE, AUSTRALIA. RECENT MULTISPECTRAL SATELLITE IMAGERY SHOWS DEEP CONVECTIVE BANDING PERSISTING OVER AN INCREASINGLY DEFINED LOW LEVEL CIRCULATION CENTER, WHICH IS ALSO EVIDENT IN RADAR DATA FROM MORNINGTON ISLAND. NEARBY SYNOPTIC OBSERVATIONS INDICATE SEA LEVEL PRESSURE NEAR 999 MB AND SUSTAINED WINDS, OUTSIDE OF THE DEEP CONVECTIVE BANDS, OF ABOUT 30 KNOTS. THE UPPER LEVEL ENVIRONMENT IS FAVORABLE FOR FURTHER DEVELOPMENT, WITH LOW VERTICAL WIND SHEAR AND STRONG EASTWARD AND POLEWARD OUTFLOW ALOFT. THE CIRCULATION CENTER IS CLOSE TO LAND, AND MAY TRACK INLAND BEFORE THIS DISTURBANCE CONSOLIDATES INTO A TROPICAL CYCLONE. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 MB. BASED ON IMPROVING ORGANIZATION AND FAVORABLE UPPER LEVEL CONDITIONS, 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 280300Z.// ========================================================================= WTPS31 PGTW 20131127 09:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 006// RMKS/ 1. TROPICAL CYCLONE 02S (ALESSIA) 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: 270600Z --- NEAR 15.8S 137.6E MOVEMENT PAST SIX HOURS - 110 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 030 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: 15.8S 137.6E --- FORECASTS: 12 HRS, VALID AT: 271800Z --- 16.2S 138.2E 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: 150 DEG/ 03 KTS --- 24 HRS, VALID AT: 280600Z --- 16.7S 138.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 160 DEG/ 04 KTS --- 36 HRS, VALID AT: 281800Z --- 17.5S 138.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 48 HR POSIT: 165 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 290600Z --- 18.3S 139.0E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 270900Z POSITION NEAR 15.9S 137.7E. TROPICAL CYCLONE 02S (ALESSIA), LOCATED APPROXIMATELY 105 NM WEST- NORTHWEST OF MORNINGTON ISLAND, AUSTRALIA, HAS TRACKED EAST- SOUTHEASTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) IN CONJUNCTION WITH RADAR IMAGERY FROM MORNINGTON ISLAND SHOWS A WELL DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) HAS REDEVELOPED OVER THE GULF OF CARPENTARIA. CURRENT DVORAK ESTIMATES INDICATE THE SYSTEM HAS REACHED 35 KNOTS, CONSTITUTING THE RE-ISSUANCE OF WARNINGS. UPPER LEVEL ANALYSIS INDICATES AN ANTICYCLONE OVER THE NORTHERN TERRITORY IS PROVIDING RADIAL OUTFLOW AND MODERATE LEVELS OF VERTICAL WIND SHEAR NEAR THE LLCC. SEA SURFACE TEMPERATURES IN THE GULF OF CARPENTARIA ARE VERY FAVORABLE FOR FURTHER DEVELOPMENT, BUT MODEL GUIDANCE AND THE MSI INDICATE THIS SYSTEM WILL BE SHORT-LIVED AS IT TRACKS ALONG THE COAST, EVENTUALLY MOVING OVER LAND IN THE NEXT 24 HOURS. DUE TO POOR CONSISTENCY IN THE AVAILABLE MODEL GUIDANCE THERE IS LOW CONFIDENCE IN THE FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270600Z IS 8 FEET. NEXT WARNINGS AT 272100Z AND 280900Z.// ========================================================================= WTPS31 PGTW 20131127 21:00z MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 02S (ALESSIA) WARNING NR 007// RMKS/ 1. TROPICAL CYCLONE 02S (ALESSIA) 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: 271800Z --- NEAR 16.5S 137.7E MOVEMENT PAST SIX HOURS - 180 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA 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 LAND REPEAT POSIT: 16.5S 137.7E --- FORECASTS: 12 HRS, VALID AT: 280600Z --- 16.7S 137.0E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 272100Z POSITION NEAR 16.6S 137.5E. TROPICAL CYCLONE (TC) 02S (ALESSIA), LOCATED APPROXIMATELY 462 NM EAST-SOUTHEAST OF DARWIN, AUSTRALIA, HAS TRACKED SOUTHWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION OVER THE EASTERN SEMI-CIRCLE OF A POORLY-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). RADAR IMAGERY FROM MORNINGTON ISLAND INDICATES THAT THE LLCC HAS TRACKED BACK OVER LAND AND HAS WEAKENED SIGNIFICANTLY. A 271242Z ASCAT IMAGE SHOWS ONLY 15 TO 25 KNOT WINDS OVER THE EASTERN SEMI-CIRCLE. SURFACE OBSERVATIONS LOCATED OVER THE WESTERN SEMI-CIRCLE OF THE SYSTEM INDICATE SUSTAINED WINDS LESS THAN 10 KNOTS AND SLP NEAR 1003 MB. THE INITIAL POSITION IS BASED ON RADAR IMAGERY WITH LOW CONFIDENCE DUE TO THE LACK OF CONVECTIVE BANDING INTO THE CENTER. THE INITIAL INTENSITY IS ASSESSED AT 30 KNOTS AND IS BASED ON THE ASCAT DATA. TC 02S IS DRIFTING SOUTHWARD AND IS EXPECTED TO REMAIN OVER LAND AS IT TRACKS WESTWARD UNDER THE LOW-LEVEL SUBTROPICAL RIDGE POSITIONED TO THE SOUTH. DYNAMIC MODELS INDICATE SLOW TRACK SPEEDS AND A GENERALLY WESTWARD TRACK WITH A LOW PROBABILITY OF TRACKING BACK OVER THE GULF OF CARPENTARIA. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO THE LACK OF CONVECTIVE STRUCTURE AND WEAK STEERING ENVIRONMENT. 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.//
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
Document: tropical_cyclone_alessia_jtwc_advisories.htm
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