1. Shower activity associated with an area of disturbed weather located
a little more than 1000 miles southwest of the southern tip of the
Baja California peninsula has become better organized since
yesterday. Environmental conditions are favorable for additional
development, and a tropical depression or tropical storm is likely
form by early next week. This system is expected to move westward
to west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.
WTPN21 PHNC 270430
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 99E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 10.3N 118.5W TO 12.9N 129.7W
WITHIN THE NEXT 12 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
270400Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 10.6N
120.0W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 10 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 99E) HAS PERSISTED NEAR
10.6N 120.0W, APPROXIMATELY 1325NM SOUTH OF SAN DIEGO, CALIFORNIA.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS FLARING DEEP
CONVECTION OVER A BROAD LOW-LEVEL CIRCULATION. A 270014Z SSMIS 91GHZ
MICROWAVE IMAGE DEPICTS SHALLOW BANDING WRAPPING INTO A DEFINED
CENTER WITH FORMATIVE DEEP CONVECTIVE BANDING. SST VALUES ARE
CONDUCIVE AT 28-29C. UPPER-LEVEL ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT WITH FAIR OUTFLOW AND LOW VERTICAL WIND SHEAR. GLOBAL
DYNAMIC MODELS INDICATE A WEST-NORTHWESTWARD TRACK WITH GRADUAL
INTENSIFICATION OVER THE NEXT TWO DAYS. 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
280430Z.//
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