WTPN22 PGTW 301200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/300152Z SEP 12//
AMPN/REF A IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 300200)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 185 NM RADIUS OF 15.1N 113.1E 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 17 TO 22 KNOTS. METSAT IMAGERY AT 301132Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 14.9N 113.1E. THE SYSTEM IS
QUASI-STATIONARY.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.9N
113.2E, IS NOW LOCATED NEAR 15.2N 113.1E, APPROXIMATELY 325 NM EAST-
SOUTHEAST OF HUE, VIETNAM. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS DEEP CONVECTION HAS BEEN CONSOLIDATING OVER A
QUICKLY IMPROVING LOW LEVEL CIRCULATION CENTER (LLCC) WITHIN THE
MONSOON TROUGH. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS ABOUT
07 DEGREES SOUTH OF THE RIDGE AXIS IN AN AREA OF LOW (05-10 KNOT)
VERTICAL WIND SHEAR. WATER VAPOR ANIMATION SHOWS IMPROVING
EQUATORWARD OUTFLOW, WITH A POLEWARD CHANNEL STARTING TO DEVELOP. A
RECENT ASCAT PASS INDICATED WINDS WERE BETWEEN 15 TO 20 KNOTS NEAR
THE CENTER, WITH THE STRONGEST WINDS LOCATED IN THE NORTHWESTERN
QUADRANT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 17 TO 22
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB.
BASED ON IMPROVING CONVECTIVE SIGNATURE IN A FAVORABLE SURFACE AND
UPPER LEVEL ENVIRONMENT, 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
011200Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 14.6N 150.7E.//