WDPN31 PGTW 130900 
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 03W (THREE) 
WARNING NR 003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 03W (THREE), LOCATED APPROXIMATELY 139 NM 
EAST OF DAVAO, PHILIPPINES, HAS TRACKED WESTWARD AT 11 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS 
AN EXPOSED LOW-LEVEL CIRCULATION (LLC) DISPLACED WEST OF AN ISOLATED 
DEEP CONVECTIVE BURST. HOWEVER, A 130721Z SSMI 91GHZ COLOR COMPOSITE 
MICROWAVE IMAGE AND A 130725Z GMI 37GHZ MICROWAVE IMAGE INDICATE 
SHALLOW BANDING WRAPPING INTO A COMPACT, WELL-DEFINED LLC, WHICH 
SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. THE INITIAL 
INTENSITY REMAINS ASSESSED AT 35 KNOTS BASED ON A 130500Z ADT 
ESTIMATE OF 2.5 (35 KNOTS) AND A KNES DVORAK INTENSITY ESTIMATE OF 
T2.5 (35 KNOTS). ENVIRONMENTAL ANALYSIS INDICATES A MARGINALLY-
FAVORABLE ENVIRONMENT WITH LOW VERTICAL WIND SHEAR (VWS), WEAK 
POLEWARD OUTFLOW AND WARM SST VALUES (29C). TS 03W IS TRACKING 
WESTWARD ALONG THE SOUTHERN PERIPHERY OF A LOW- TO MID-LEVEL 
SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH.
3. FORECAST REASONING.
   A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE 
PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS 03W IS FORECAST TO TRACK WESTWARD TO WEST-NORTHWESTWARD 
THROUGH THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF THE STR 
POSITIONED TO THE NORTH. NUMERICAL MODEL GUIDANCE REMAINS IN FAIR 
AGREEMENT WITH A 90-135NM SPREAD IN SOLUTIONS AT TAU 48 TO TAU 72, 
LENDING MODERATE CONFIDENCE TO THE JTWC OFFICIAL FORECAST TRACK. TS 
03W IS EXPECTED TO INTENSIFY SLIGHTLY TO 40 KNOTS BY TAU 12 BUT WILL 
WEAKEN AS IT TRACKS OVER MINDANAO FROM TAU 12 TO TAU 36. AFTER TAU 
36, TS 03W WILL GRADUALLY DISSIPATE DUE TO INCREASING VWS (20-25 
KNOTS) AND UPPER-LEVEL CONVERGENCE ASSOCIATED WITH A PERSISTENT 
UPPER-LEVEL TROUGH.//
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