WTPS22 PGTW 230930
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 250 NM RADIUS OF 20.7S 178.3W WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CY-
CLONE WARNINGS AT THIS TIME.  WINDS IN THE AREA ARE ESTIMATED TO
BE 25 TO 30 KNOTS. METSAT IMAGERY AT 230832Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 19.4S 178.0W.  THE SYSTEM IS
MOVING SOUTHWESTWARD AT 14 KNOTS.
2. REMARKS:
THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 19.2S 177.5W,
IS NOW LOCATED NEAR 19.5S 178.1W, APPROXIMATELY 275 NM EAST-
SOUTHEAST OF NADI, FIJI. ANIMATED INFRARED IMAGERY DEPICTS
ORGANIZED DEEP CONVECTION AROUND THE EASTERN PERIPHERY OF THE LOW
LEVEL CIRCULATION CENTER (LLCC). THE CURRENT INTENSITY IS BASED ON A
DVORAK INTENSITY ESTIMATE OF 30 KTS FROM PGTW AT 23/0832Z. 23/0000Z
UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS BENEATH AN ANTICYCLONE,
AND ANIMATED WATER VAPOR IMAGERY SHOWS ENHANCED EQUATORWARD AND
EASTWARD OUTFLOW. INCREASED CONVECTIVE BANDING EXTENDING TO THE
NORTH AND EAST OF THE LLCC IS EVIDENT ON A 23/0708Z SSMIS MICROWAVE
IMAGE. VERTICAL WIND SHEAR OF 10 TO 15 KNOTS AND SEA SURFACE
TEMPERATURES OF 28 TO 30 DEGREES CELSIUS ARE FAVORABLE FOR
DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO
30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003
MB. DUE TO INCREASED DEEP CONVECTION AND UPPER LEVEL OUTFLOW, THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
240930Z.//