WTPN21 PGTW 240200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INEVEST 98W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
035 NM EITHER SIDE OF A LINE FROM 24.4N 119.2E TO 26.4N 119.0E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 240200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 24.6N 119.2E. THE SYSTEM IS MOVING NORTHWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 98W) IS LOCATED NEAR 24.6N
119.2E, APPROXIMATELY 127 NM WEST-SOUTHWEST OF TAIPEI, TAIWAN.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN EXPOSED LOW-
LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION ALONG THE
EAST-SOUTHEAST PERIPHERY OF THE CIRCULATION. ANIMATED RADAR DATA SHOWS
A WELL-DEFINED CIRCULATION WITH MODERATE CONVECTIVE BANDS WRAPPING
INTO THE LLCC AND MORE CONCENTRATED CONVECTION TO THE SOUTHEAST NEAR
THE WEST COAST OF TAIWAN. RECENT OBSERVATIONS FROM ACROSS THE REGION
DEPICT GENERALLY SOUTHERN WINDS OF 15-20KTS WITH GUSTS AS HIGH AS
35KTS, PARTICULARLY FROM THE PENGHU ISLANDS. ENVIRONMENTAL ANALYSIS
REVEALS FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW VERTICAL WIND
SHEAR (10 TO 15KTS), WARM SEA SURFACE TEMPERATURES (27 TO 28 C), AND
GOOD UPPER-LEVEL OUTFLOW. GLOBAL DETERMINISTIC AND ENSEMBLE MODELS ARE
IN POOR AGREEMENT ON A SHORT WINDOW FOR DEVELOPMENT OF INVEST 98W. GFS
STALLS THE SYSTEM OVER WATER FOR ABOUT 24 HOURS, ALLOWING FOR A BRIEF
PERIOD OF DEVELOPMENT, WHILE THE ECMWF MOVES THE CIRCULATION OVER LAND
MORE QUICKLY, DENYING TIME FOR THE SYSTEM TO DEVELOP FURTHER. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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.//
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