MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 4.1N 79.3E TO 10.4N 72.8E 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 25 TO 30 KNOTS. METSAT IMAGERY AT
250730Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 4.9N
78.3E. THE SYSTEM IS MOVING NORTHWESTWARD AT 13 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 4.1N
79.3E, IS NOW LOCATED NEAR 4.9N 78.3E, APPROXIMATELY 150 NM
SOUTHWEST OF COLOMBO, SRI LANKA. RECENT ANIMATED MULTISPECTRAL
SATELLITE IMAGERY SHOWS DEEP PERIPHERAL CONVECTION ASSOCIATED WITH
CONVERGING NORTHERLIES INTO WESTERLIES. A 250431Z ASCAT IMAGE
INDICATES 25 KNOT EASTERLIES POLEWARD OF 25-30 KNOT WESTERLIES NEAR
THE LOW LEVEL CIRCULATION CENTER (LLCC). A 250253Z 37 GHZ SSMIS
IMAGE SHOWS TIGHTLY CURVED BANDING IN THE LOWER LEVEL CONVECTIVE
STRUCTURE WITH A LARGE, SOMEWHAT LINEAR, CONVECTIVE BAND OVER THE
SOUTHERN PORTION OF THE SYSTEM. UPPER LEVEL ANALYSIS INDICATES THAT
THE LLCC IS UNDER A POINT SOURCE OF DIVERGENCE WITH WEAK (05-10
KNOT) VERTICAL WIND SHEAR. RECENT ANIMATED WATER VAPOR IMAGERY SHOWS
EXCELLENT RADIAL OUTFLOW. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1001 MB. DUE TO THE 25-30 KNOT WINDS NEAR THE LLCC,
EXCELLENT UPPER LEVEL DIVERGENCE AND OUTFLOW, AND ACTIVE PHASE OF
THE MADDEN-JULIAN OSCILLATION IN THE REGION, THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
![Image](http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/warnings/io9811.gif)