WTPN21 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 11.9N 158.6E TO 16.0N 153.8E
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 AT 020600Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.5N 157.8E. THE SYSTEM IS MOVING NORTHWESTWARD AT 10
KNOTS.
2. REMARKS:
THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED NEAR 10.3N
159.4E, IS NOW LOCATED NEAR 12.5N 157.8E, APPROXIMATELY 465 NM
NORTHEAST OF CHUUK. ANIMATED MULTISPECTRAL SATELLITE IMAGERY, ALONG
WITH A 020645Z SSMIS F-18 91GHZ MICROWAVE IMAGE, SHOWS BUILDING DEEP
CONVECTION OVERHEAD A CONSOLIDATING LOW LEVEL CIRCULATION CENTER
(LLCC) SURROUNDED BY FRAGMENTED DEEP CONVECTION. 99W IS CURRENTLY IN
A FAVORABLE ENVIRONMENT WITH EXCELLENT RADIAL OUTFLOW, LOW (10 TO 15
KNOT) VERTICAL WIND SHEAR, AND WARM (29 TO 30 CELSIUS) SEA SURFACE
TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 99W WILL
CONTINUE TO TRACK NORTHWESTWARD AND INTENSIFY WITHIN THE NEXT 24-36
HOURS. 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
030900Z.//
NNNN