Tropical Cyclone Formation Alert

WTPN21 PGTW 081630
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 12.0N 137.4E TO 13.6N 133.3E
WITHIN THE NEXT 06 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 081200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.1N 136.7E. THE SYSTEM IS MOVING WESTWARD AT 05 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.1N
136.7E, IS NOW LOCATED NEAR 12.4N 136.5E, APPROXIMATELY 300 NM NORTH-
NORTHEAST OF PALAU. RECENT INFRARED SATELLITE IMAGERY DEPICTS A
BROAD, YET CONSOLIDATING, LOW-LEVEL CIRCULATION CENTER (LLCC) WITH A
FRAGMENTED BANDING FEATURE ACROSS THE NORTHERN SEMI-CIRCLE AND
PERSISTENT CENTRAL CONVECTION. A 081100Z SSMIS 37GHZ MICROWAVE IMAGE
REVEALS CENTRAL CONVECTION CONTINUES TO IMPROVE WITH FORMATIVE
BANDING FEATURES THAT ARE BEGINNING TO WRAP INTO THE LLCC. A 081159Z
ASCAT PASS REVEALS A BROAD CIRCULATION WITH 15 TO 20 KNOT WINDS NEAR
THE CONSOLIDATING LLCC. SEA SURFACE TEMPERATURES IN THE AREA ARE
FAVORABLE FOR DEVELOPMENT AT 28 TO 30 DEGREES CELSIUS. UPPER LEVEL
ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH A POINT SOURCE
LOCATED JUST EAST OF THE SYSTEM WHICH IS PROVIDING DIFFLUENT
EASTERLY FLOW AND WEAK (5 TO 10 KNOTS) VERTICAL WIND SHEAR. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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
091630Z.//
NNNN