WTPN21 PHNC 201930
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 91E)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 8.9N 95.5W TO 11.4N 98.1W
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 201900Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 9.0N 95.6W. THE SYSTEM IS MOVING NORTHWESTWARD AT 04 KNOTS.
2. REMARKS: AN AREA OF CONVECTION (INVEST 91E) IS LOCATED NEAR 9.0N 
95.6W, APPROXIMATELY 1850 NM SOUTHEAST OF SAN DIEGO, CA. ANIMATED 
MULTISPECTRAL SATELLITE IMAGERY AND A 201322Z SSMIS 91 GHZ MICROWAVE 
IMAGE DEPICT AN EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP 
CONVECTION DISPLACED WESTWARD OF THE CIRCULATION CENTER. ENVIRONMENTAL 
ANALYSIS INDICATES THAT 91E IS IN A MARGINALLY FAVORABLE ENVIRONMENT FOR 
DEVELOPMENT WITH LOW (5-10 KTS) VERTICAL WIND SHEAR AND WARM (28-29 C) 
SST OFFSET BY MARGINAL OUTFLOW ALOFT DUE PREDOMINATELY TO STRONG 
EASTERLY FLOW OVER THE AREA. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 
91E WILL TRACK SLOWLY NORTHWESTWARD AS IT GRADUALLY DEVELOPS OVER THE 
NEXT 24-48 HOURS. 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 
211930Z.
//
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