99W TCFA - 颱風討論

WTPN21 PGTW 012230
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
165 NM EITHER SIDE OF A LINE FROM 23.3N 145.9E TO 24.2N 140.8E
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 18 TO 23 KNOTS. METSAT IMAGERY AND
SYNOPTIC DATA AT 012200Z INDICATE THAT A CIRCULATION CENTER IS
LOCATED NEAR 23.4N 145.3E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD
AT 07 KNOTS.

2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 22.3N
145.5E IS NOW LOCATED NEAR 23.4N 145.3E, APPROXIMATELY 230 NM EAST-
SOUTHEAST OF IWO-TO, JAPAN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) INDICATES AN ORGANIZED, EXPOSED, SYMMETRIC LOW LEVEL
CIRCULATION CENTER (LLCC) DISPLACED 120 NM WEST OF A CURVED BAND OF
DEEP CONVECTION. MSI ALSO SHOWS AN EXTENSIVE AREA OF INTENSE
CONVECTION ASSOCIATED WITH STRONGLY CONVERGENT WESTERLY SURFACE
FLOW. RECENT SHIP OBSERVATIONS OVER THE SOUTHERN SEMI-CIRCLE INDICATE
CONVERGENT WESTERLY WINDS OF 22-26 KNOTS WITH SLP VALUES RANGING FROM
1003-1005 MB. A 012036Z SSMIS 91GHZ IMAGE ALSO INDICATES A SLIGHTLY
ELONGATED BUT RAPIDLY DEVELOPING LLCC WITH WELL-DEFINED SHALLOW
CONVECTIVE BANDING. RECENT TOTAL PRECIPITABLE WATER IMAGERY SHOWS A
WELL-DEFINED LLCC WITH A CONSOLIDATING, DEEP MOISTURE ENVELOPE.
RECENT ANIMATED WATER VAPOR IMAGERY DEPICTS INCREASING POLEWARD
OUTFLOW INTO THE TROPICAL UPPER TROPOSPHERIC TROUGH AND FAVORABLE
EQUATORWARD OUTFLOW; HOWEVER, THE GOOD OUTFLOW IS OFFSET SOMEWHAT BY
STRONG (30-40 KNOTS) NORTHWESTERLY VERTICAL WIND SHEAR (VWS).
DYNAMIC MODELS INDICATE THE SYSTEM WILL DEVELOP QUICKLY AS VWS
DECREASES WITHIN THE NEXT 24 HOURS. SYSTEM IS EXPECTED TO TRACK
WESTWARD TOWARD OKINAWA. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1002 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
022230Z.//
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