熱帶氣旋形成警報WTXS21 於10 / 0230Z發布 TCFA文本 WTXS21 PGTW 100230 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE FORMATION ALERT// REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/100121Z NOV 18// AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 100130)// RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN A 120 NM RADIUS OF 4.9S 91.0E 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 23 TO 28 KNOTS. METSAT IMAGERY AT 100000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 4.8S 90.9E. THE SYSTEM IS MOVING EASTWARD AT 03 KNOTS. 2. REMARKS: THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED NEAR 4.2S 85.8E, IS NOW LOCATED NEAR 5.2S 90.7E, APPROXIMATELY 558 NM NORTHWEST OF COCOS ISLANDS. ANIMATED ENHANCED INFRARED IMAGERY SHOWS PERSISTENT DEEP CONVECTION BEGINNING TO WRAP INTO THE LLCC. A 091931Z AMSR2 GW1 89GHZ SHOWS DEEP CONVECTION WRAPPING INTO THE LLCC FROM THE SOUTH. A 092302Z METOP-A ASCAT PASS SHOWS A SLIGHTLY ELONGATED LLCC WITH A SMALL GROUPING OF 30 KNOT WINDS TO THE SOUTH. 93S IS IN A FAVORABLE ENIRONMENT WITH VERY GOOD POLEWARD OUTFLOW, 10 TO 20 KNOT VWS, AND 26 TO 28 DEGREE CELSIUS SSTS. GLOBAL MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE SYSTEM WILL CONTINUE TO INTENSIFY, BUT ARE SPLIT BETWEEN THE SYSTEM SLOWLY TRACKING TO THE SOUTHEAST OR SOUTHWEST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH. 3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 110130Z.//NNNN
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 4.2S 85.8E,
IS NOW LOCATED NEAR 4.4S 85.3E, APPROXIMATELY 787 NM EAST-NORTHEAST
OF DIEGO GARCIA. A RECENT 061508Z ASCAT METOP-A PASS SHOWS A
SLIGHTLY ELONGATED LOW LEVEL CIRCULATION (LLC) WITH A SMALL SWATH OF
15 KNOT WINDS TO THE SOUTH. A 061302Z SSMIS F-17 91GHZ MIRCROWAVE
IMAGE SHOWS THAT THE MAJORITY OF THE CONVECTION ABOVE THE LLC HAS
DISSIPATED AND THE STRUCTURE HAS LARGELY FALLEN APART. THE SYSTEM IS
SITTING IN A MARGINAL ENVIRONMENT WITH MODERATE UPPER LEVEL OUTFLOW
AND VERTICAL WIND SHEAR OF 10 TO 15 KNOTS WITH SEA SURFACE
TEMPERATURES OF 26 TO 28 DEGREES CELSIUS. GLOBAL MODELS DISAGREE ON
INTENSIFICATION AND TRACK OF THE SYSTEM. NAVGEM IS BRINGING IT
SOUTHWARD AND ONLY SLIGHTLY INTENSIFYING THE SYSTEM. WHILE MOST OF
THE OTHER MODELS SHOW VERY LITTLE TO NO DEVELOPMENT. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.
(1) AN AREA OF CONVECTION (INVEST 93S) HAS PERSISTED NEAR 4.4S
89.1E, APPROXIMATELY 1005 NM EAST OF DIEGO GARCIA. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW LEVEL
CIRCULATION WITH WEAK FORMATIVE BANDING IN THE SOUTHERN ARC OF THE
SYSTEM. THE UPPER LEVEL ENVIRONMENT IS OVERALL MARGINAL, WITH
MODERATE (15-20KTS) VWS AND WEAK DIVERGENCE ALOFT DUE TO A FORMATIVE
POLEWARD OUTFLOW CHANNEL. SSTS ARE WARM (27-29C) IN THE EQUATORIAL
INDIAN OCEAN AND WILL SUPPORT FURTHER DEVELOPMENT. GLOBAL MODELS
GENERALLY AGREE ON WEAK DEVELOPMENT POSSIBLY OCCURRING IN THE LATE
TAUS AS THE SYSTEM TAKES A MEANDERING TRACK TO THE WEST-SOUTHWEST.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS LOW.
