Tropical Cyclone Formation AlertWTPN21 PHNC 131000
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 8.2N 90.5W TO 12.4N 95.0W WITH-
IN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY IS-
SUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS
IN THE AREA ARE ESTIMATED TO BE 15 TO 20 KNOTS. METSAT IMAGERY AT
130930Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 7.9N
90.0W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 07 KNOTS.
2. REMARKS: AN AREA OF CONVECTION HAS PERSISTED NEAR 7.9N 90.0W,
APPROXIMATELY 340 NM SOUTH OF SAN SALVADOR, EL SALVADOR. ANIMATED
INFRARED SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION
FLARING OVER A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC). A
130200Z SSMIS 91 GHZ IMAGE SHOWS BROADLY TURNING DEEP CONVECTIVE
BANDS AROUND THE PERIPHERY WITH A SMALL HOOK FEATURE NEAR THE LLCC.
A 130247 PARTIAL ASCAT PASS INDICATES 20 KNOT WINDS OVER THE EASTERN
SEMI-CIRCLE OF THE LLCC. UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM
IS UNDER SPLIT FLOW DIVERGENCE WITH WEAK VERTICAL WIND SHEAR (05-10
KNOTS) AND GOOD DIVERGENCE ALOFT. SEA SURFACE TEMPERATURES ARE
FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT AT 28-30 DEGREES CELSIUS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. DUE TO
THE INCREASED CONSOLIDATION OF THE LLCC, PERSISTENT DEEP CONVECTION,
AND FAVORABLE ENVIRONMENT, 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
141000Z.//
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