![Image](http://i.imgur.com/vQM6WaT.gif)
WTPN21 PGTW 210430
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 17.9N 125.1E TO 20.0N 121.0E
WITHIN THE NEXT 06 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 20 TO 25 KNOTS. METSAT IMAGERY AT
210400Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 18.1N
124.7E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 04 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 98W) HAS PERSISTED NEAR
18.1N 124.7E, APPROXIMATELY 366NM SOUTHEAST OF KAOHSIUNG, TAIWAN.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A RAPIDLY
CONSOLIDATING, SMALL (240NM DIAMETER) LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH IMPROVING DEEP CONVECTIVE BANDING. A 210135Z METOP-B
89GHZ IMAGE SHOWS CURVED CONVECTIVE BANDING WRAPPING INTO THE LLCC.
A 210138Z PARTIAL ASCAT IMAGE REVEALS 20 TO 25 KNOT WINDS OVER THE
EASTERN SEMI-CIRCLE OF THE CIRCULATION. UPPER-LEVEL ANALYSIS AND
ANIMATED WATER VAPOR IMAGERY INDICATE A FAVORABLE ENVIRONMENT WITH
DIFFLUENT OUTFLOW ALOFT AND LOW TO MODERATE VERTICAL WIND SHEAR.
GLOBAL MODELS ARE HAVING PROBLEMS RESOLVING THE SMALL SYSTEM BUT
INDICATE A GENERAL NORTHWESTWARD TRACK WITH NO SIGNIFICANT
DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO
25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004
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
220430Z.//
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