
WTPN21 PGTW 162100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 7.4N 122.7E TO 10.2N 113.3E
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 161800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 7.7N 121.8E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 18
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED
NEAR 7.7N 121.8E IS NOW LOCATED NEAR 8.0N 120.8E, APPROXIMATELY
175NM EAST-SOUTHEAST OF PUERTO PRINCESA, PHILIPPINES. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY SHOWS A WIDESPREAD AREA OF
DISORGANIZED CONVECTION THAT IS BEGINNING TO CONSOLIDATE WEST OF
MINDANAO. A 161800Z HIMAWARI INFRARED SATELLITE IMAGE DEPICTS
INCREASING CONVECTION ASSOCIATED WITH THE LOW LEVEL CIRCULATION
CENTER (LLCC). UPPER-LEVEL ANALYSIS INDICATES A MODERATE AMOUNT OF
WIND SHEAR (5-20 KNOTS). EQUATORWARD OUTFLOW IS FAVORABLE. POLEWARD
OUTFLOW IS MODERATELY FAVORABLE BUT WILL HAVE LIMITED INTERACTION
WITH THE UPPER LEVEL JET STREAM, WHICH WILL LIMIT DEVELOPMENT. SEA
SURFACE TEMPERATURES ARE FAVORABLE AT 27-28 DEGREES CELSIUS. GLOBAL
NUMERICAL MODELS FORECAST 90W TO PROPAGATE WEST-NORTHWESTWARD
THROUGH THE SULU SEA AND EVENTUALLY INTO THE SOUTH CHINA SEA. 90W
WILL INTENSIFY AS IT TRACKS WEST-NORTHWESTWARD OVER OPEN WATER WITH
FAVORABLE TO MODERATE UPPER LEVEL CONDITIONS. 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
172100Z.
//
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