WTXS21 PGTW 130130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 92S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN A 
190 NM RADIUS OF 32.0S 30.5E 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 35 TO 40 KNOTS. METSAT IMAGERY AT 130100Z INDICATES THAT A 
CIRCULATION CENTER IS LOCATED NEAR 32.0S 30.5E. THE SYSTEM IS MOVING 
SOUTHWESTWARD AT 08 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED 
NEAR 31.4S 31.2E IS NOW LOCATED NEAR 32.0S 30.5E, APPROXIMATELY 145 
NM EAST-NORTHEAST OF EAST LONDON, SOUTH AFRICA. THE SYSTEM IS 
CURRENTLY CLASSIFIED AS A SUBTROPICAL STORM, GENERALLY CHARACTERIZED 
AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES. ANIMATED 
ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A COMPACT SYSTEM 
WITH A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) AND 
PERSISTENT DEEP CONVECTION OVER THE NORTHERN SEMICIRCLE. A 122245Z 
AMSR2 89GHZ COLOR COMPOSITE MICROWAVE IMAGE SHOWS SHALLOW BANDING 
WRAPPING TIGHTLY INTO A WELL-DEFINED LLCC WITH LIMITED DEEP 
CONVECTIVE BANDING OVER THE NORTHEAST QUADRANT. A 120737Z ASCAT-C 
IMAGE REVEALS A SYMMETRIC CIRCULATION WITH 35-40 KT WINDS AND A 
RADIUS OF MAXIMUM WINDS OF 30NM. UPPER-LEVEL ANALYSIS INDICATES THE 
SYSTEM IS LOCATED UNDER A BROAD UPPER LOW BUT HAS MAINTAINED 
VIGOROUS ANTICYCLONIC, POLEWARD OUTFLOW. SST VALUES ARE MARGINAL AT 
24 TO 26C. THE SYSTEM IS VERTICALLY STACKED UNDER A 500MB LOW WITH 
MODERATE BAROCLINICITY BUT HAS MAINTAINED A WARM CORE. THE SYSTEM 
HAS DEVELOPED ORGANIZED CORE CONVECTION, WHICH HAS WEAKENED SOMEWHAT 
OVER THE PAST SIX HOURS, BUT MAY TRANSITION TO A TROPICAL CYCLONE IF 
IT CAN SUSTAIN ORGANIZED CENTRAL CONVECTION. GLOBAL MODELS INDICATE 
A QUASI-STATIONARY TRACK OVER THE NEXT 12-24 HOURS THEN AN EASTWARD 
TRACK WITHIN THE UPPER-LEVEL WESTERLIES. MAXIMUM SUSTAINED SURFACE 
WINDS ARE ESTIMATED AT 35 TO 40 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 993 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 
140130Z.//
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