WTPN21 PGTW 291430
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
220 NM EITHER SIDE OF A LINE FROM 12.3N 164.8E TO 12.1N 155.1E
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 15 TO 20 KNOTS. METSAT IMAGERY AT
291400Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.0N
162.6E. THE SYSTEM IS MOVING WESTWARD AT 14 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.2N
164.7E IS NOW LOCATED NEAR 12.0N 162.6E, APPROXIMATELY 315 NM
NORTHWEST OF KWAJALEIN ATOLL. ANIMATED ENHANCED SATELLITE
IMAGERY DEPICTS AN AREA OF PERSISTENT DEEP CONVECTION AND STRONG MID-
LEVEL TURNING OVER A PARTIALLY-EXPOSED LOW LEVEL CIRCULATION CENTER
(LLCC). A 291021Z METOP-B 89 GHZ IMAGE SUGGESTS A CONSOLIDATING LLCC
WITH FRAGMENTED, FORMATIVE BANDING. A 291021Z ASCAT PARTIAL IMAGE
REVEALS AN AREA OF 15 TO 20 KNOT WINDS OVER THE NORTHERN SEMI-CIRCLE
WITH 10 TO 15 KNOT WINDS ELSEWHERE. UPPER-LEVEL ANALYSIS INDICATES A
MARGINALLY-FAVORABLE ENVIRONMENT WITH LOW TO MODERATE VERTICAL WIND
SHEAR OFFSET BY GOOD POLEWARD OUTFLOW, ENHANCED BY A TUTT CELL
POSITIONED TO THE NORTH-NORTHWEST. SEA SURFACE TEMPERATURES ABOVE 28
CELSIUS AND HIGH OCEAN HEAT CONTENT ARE CONDUCIVE FOR FURTHER
DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO
20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006
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
301430Z.//
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