TCFA: JTWC
WTPN21 PGTW 050900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 11.1N 118.3E TO 14.9N 111.4E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 050732Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.8N 117.4E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 11
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 11.5N
118.5E IS NOW LOCATED NEAR 11.8N 117.4E, APPROXIMATELY 690 NM SOUTH-
SOUTHEAST OF HONG KONG. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) INDICATES DEEP CONVECTIVE BANDING DEVELOPING ALONG THE
WESTERN AND SOUTHERN SEMI-CIRCLES OF A CONSOLIDATING LOW-LEVEL
CIRCULATION CENTER (LLCC). THOUGH THE SYSTEM IS IMPROVING, THE MSI
INDICATES THAT SYSTEM IS STILL WEAKLY DEFINED AND MULTIPLE LOW LEVEL
VORTICES COULD BE PRESENT. A 050155Z METOP-B MICROWAVE IMAGE REVEALS
THE DEVELOPING BANDING STRUCTURE ALONG THE WESTERN HALF OF THE
SYSTEM. A 050452Z SCATTEROMETRY PASS DEPICTS THE WESTERN PORTION OF
THE LLCC AND CONFIRMS THE PRESENCE OF A CLOSED CIRCULATION WITH 20
TO 25 KNOT WIND BARBS. UPPER LEVEL ANALYSIS INDICATES THE
DISTURBANCE IS JUST SOUTH OF THE RIDGE AXIS IN AN AREA OF LOW TO
MODERATE (10-20 KNOT) VERTICAL WIND SHEAR. HOWEVER, ANIMATED WATER
VAPOR IMAGERY CONTINUES TO SHOW EXCELLENT RADIAL OUTFLOW. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. DUE TO THE INCREASED
CONSOLIDATION OF THE LLCC, 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
060900Z.//
NNNN
![Image](http://img89.imageshack.us/img89/2686/4737.gif)