WDPN31 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (NANMADOL) WARNING 
NR 11//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM 05W (NANMADOL), LOCATED APPROXIMATELY 73 NM SOUTH
OF CAMP FUJI, HAS TRACKED EASTWARD AT 37 KNOTS OVER THE PAST SIX
HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM 
TRACKING OUT OVER WATER SOUTH OF SURUGA BAY. THE INITIAL POSITION IS 
BASED ON A 041136Z GMI MICROWAVE IMAGE DEPICTING CONVECTIVE BANDING 
WRAPPING INTO A LOW LEVEL CIRCULATION CENTER. THE INITIAL INTENSITY 
OF 35 KNOTS IS HEDGED ON THE LOWER END OF MULTI-AGENCY DVORAK 
ESTIMATES RANGING FROM T2.5 TO T3.0 (35 TO 45 KTS)BASED ON SURFACE 
OBSERVATIONS TAKEN NEAR THE STORM. ENVIRONMENTAL ANALYSIS INDICATES 
A STRONG POLEWARD OUTFLOW CHANNEL THAT IS BEING ENHANCED BY THE MID-
LATITUDE WESTERLIES TO THE NORTH, HIGH VERTICAL WIND SHEAR (30KTS) 
AND LOW SEA SURFACE TEMPERATURES OF 24 TO 25 DEGREES CELSIUS. TS 05W 
IS TRACKING TO THE NORTHEAST ALONG THE NORTHERN PERIPHERY OF A 
SUBTROPICAL RIDGE (STR).
3. FORECAST REASONING.
   A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY 
SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE.
   B. TS NANMADOL IS FORECAST TO CONTINUE TRACKING NORTHEASTWARD 
UNDER THE INFLUENCE OF MID-LATITUDE WESTERLY FLOW ALONG THE NORTHERN 
EXTENT OF A SUBTROPICAL RIDGE. THE SYSTEM WILL FURTHER WEAKEN AS IT 
TRACKS INTO AN AREA OF LOWER SEA SURFACE TEMPERATURES AND DUE TO 
STRONG VERTICAL WIND SHEAR. AFTER TAU 6, TS 05W WILL BEGIN EXTRA- 
TROPICAL TRANSITION (ETT) AND COMPLETE ETT BY TAU 36. DYNAMIC MODEL 
GUIDANCE REMAINS IN STRONG AGREEMENT LENDING HIGH CONFIDENCE TO THE 
JTWC FORECAST TRACK.//
NNNN