WTXS21 PGTW 210730
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 14P)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 150 NM 
EITHER SIDE OF A LINE FROM 15.9S 124.4E TO 17.5S 117.0E 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 25 TO 30 KNOTS. METSAT IMAGERY, SYNOPTIC DATA AND RADAR DATA AT 
210700Z INDICATE THAT A CIRCULATION CENTER IS LOCATED NEAR 15.8S 124.0E. 
THE SYSTEM IS MOVING WESTWARD AT 08 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 14P) PREVIOUSLY LOCATED NEAR 
16.4S 125.2E IS NOW LOCATED NEAR 15.8S 124.0E, APPROXIMATELY 166 NM 
NORTHEAST OF BROOME, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
AND ANIMATED RADAR IMAGERY FROM THE BROOME RADAR DEPICT A PARTIALLY-
EXPOSED LOW-LEVEL CIRCULATION WITH FORMATIVE CONVECTIVE BANDING AND LOW-
LEVEL CLOUD LINES WRAPPING INTO A DEFINED CENTER. A 210557Z ATMS 183 GHZ 
MICROWAVE IMAGE SHOWS DEEP CONVECTIVE BANDING OVER THE NORTHERN 
PERIPHERY WRAPPING INTO THE EASTERN QUADRANT. SURFACE OBSERVATIONS FROM 
KOOLAN ISLAND (YKLC, ELEVATION 530 FT), APPROXIMATELY 21 NM SOUTHWEST OF 
THE CENTER, INDICATE EASTERLY WINDS SUSTAINED (10-MINUTE AVERAGE) AT 14-
16 KNOTS GUSTING TO 25-30 KNOTS. ENVIRONMENTAL CONDITIONS ARE FAVORABLE 
WITH GOOD EQUATORWARD OUTFLOW, MODERATE TO HIGH VERTICAL WIND SHEAR AND 
WARM SST VALUES (29-30 C). GLOBAL MODELS (GFS AND ECMWF) INDICATE A 
GENERALLY WEST-SOUTHWESTWARD TRACK WITH GRADUAL DEVELOPMENT OVER THE 
NEXT 36 TO 48 HOURS AS THE SYSTEM TRACKS AWAY FROM LAND. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 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 
220730Z.//
NNNN