WDPN32 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (MAWAR) WARNING NR 
06//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 18W (MAWAR), LOCATED APPROXIMATELY 165 NM EAST-
SOUTHEAST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 06 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) SHOWS FLARING AND FRAGMENTED CONVECTION SHEARED WESTWARD OF A
BROAD AND ILL-DEFINED LOW LEVEL CIRCULATION (LLC). THE INITIAL
POSITION IS BASED ON THE MSI LOOP AND LINED UP WITH A BROAD LOW
REFLECTIVITY CIRCULATION FEATURE IN THE 012241Z SSMIS MICROWAVE PASS
WITH FAIR CONFIDENCE. THE INITIAL INTENSITY OF 35 KNOTS IS BASED ON
AN OVERALL ASSESSMENT OF AGENCY AND OBJECTIVE DVORAK ESTIMATES. UPPER
LEVEL ANALYSIS INDICATES THE SYSTEM HAS LIMITED EQUATORWARD OUTFLOW
THAT IS PARTLY OFFSET BY MODERATE (20 KNOT) EASTERLY VERTICAL WIND
SHEAR. THE CYCLONE IS TRACKING ALONG THE WESTERN PERIPHERY OF AN
EXTENSION OF THE SUBTROPICAL RIDGE (STR) BUILDING IN THE PHILIPPINE 
SEA.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST TRACK PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.   
   B. TS MAWAR IS FORECAST TO CONTINUE ALONG ITS CURRENT TRACK FOR
THE REMAINDER OF THE FORECAST, MAKING LANDFALL OVER SOUTHEAST CHINA
BY TAU 30. THE SYSTEM MAY SEE WEAK INTENSIFICATION DUE TO THE
FAVORABLE EQUATORWARD OUTFLOW AND WARM ALONG-TRACK SSTS (30 CELSIUS),
PEAKING AT 40 KNOTS BY TAU 24. AFTER LANDFALL, TS 18W WILL RAPIDLY
ERODE DUE TO LAND INTERACTION AND DISSIPATE BY TAU 48. DYNAMIC MODEL
GUIDANCE IS IN OVERALL GOOD AGREEMENT BUT GIVEN THE BROAD AND
ILL-DEFINED NATURE OF THE LLC, THERE IS LOW CONFIDENCE IN THE JTWC
TRACK FORECAST.//
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