WDPN31 PGTW 080300Z
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 05W WARNING NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TROPICAL DEPRESSION (TD) 05W (FIVE), LOCATED APPROXIMATELY 300 
NM SOUTHWEST OF OKINAWA, JAPAN, HAS TRACKED NORTHEASTWARD AT 08 
KNOTS OVER THE PAST SIX HOURS. RECENT ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY AND A 072123Z 37 GHZ SSMIS MICROWAVE IMAGE
DEPICT TIGHTLY CURVED LOW LEVEL BANDING WRAPPING INTO A PARTIALLY 
EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). A 072229Z SSMIS 37 GHZ 
MICROWAVE IMAGE AND A 072308 89 GHZ AMSU MICROWAVE IMAGE REVEAL THAT 
A MAJORITY OF THE DEEP CONVECTION IS ALONG THE SOUTHERN SEMI-CIRCLE 
OF THE SYSTEM. THIS SYSTEM APPEARS TO HAVE DEVELOPED FROM A BROADER 
CIRCULATION WITHIN THE REVERSE MONSOON TROUGH PATTERN. THERE IS FAIR 
CONFIDENCE IN THE POSITION BASED ON THE PARTIALLY EXPOSED LLCC AT 
00Z. THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES FROM PGTW 
AND KNES OF 25 TO 30 KNOTS. ANIMATED WATER VAPOR IMAGERY INDICATES 
THE SYSTEM HAS EXCELLENT EQUATORWARD OUTFLOW AND IS ALSO 
EXPERIENCING ENHANCED POLEWARD OUTFLOW ASSOCIATED WITH A TROPICAL 
UPPER TROPOSPHERIC TROUGH (TUTT) CELL OVER JAPAN. UPPER LEVEL
ANALYSIS INDICATES THE SYSTEM HAS INCREASED DIFFLUENCE ALOFT AND IS 
EXPERIENCING LIGHT VERTICAL WIND SHEAR (05 TO 10 KNOTS).
3. FORECAST REASONING.
   A. THIS IS THE FIRST PROGNOSTIC REASONING BULLETIN AND IT 
ESTABLISHES THE FORECAST REASONING.
   B. TD 05W IS TRACKING NORTHEASTWARD ALONG THE WESTERN PERIPHERY 
OF A SOUTHERN EXTENSION OF THE SUBTROPICAL RIDGE (STR). THE STR WILL 
REMAIN THE PRIMARY STEERING INFLUENCE AS THE SYSTEM CONTINUES TO 
TRACK NORTHWARD TOWARD SOUTH KOREA. THE SYSTEM IS FORECAST TO REACH 
A PEAK INTENSITY OF 40 KNOTS NEAR TAU 48. AVAILABLE DYNAMIC AIDS ARE 
IN GOOD AGREEMENT WITH THIS SCENARIO, WITH THE EXCEPTION OF GFS, 
WHICH DRIVES THE SYSTEM ERRONEOUSLY EASTWARD AFTER TAU 24.
   C. BETWEEN TAU 72 AND TAU 96 TD 05W IS EXPECTED TO BEGIN TO 
RECURVE INTO THE SEA OF JAPAN AS IT BEGINS TO INTERACT WITH THE 
BAROCLINIC ZONE TO THE NORTH. BY TAU 96 THE SYSTEM IS FORECAST TO 
COMPLETE EXTRATROPICAL TRANSITION AS IT BECOMES ABSORBED INTO THE
MID-LATITUDE WESTERLY FLOW.//
NNNN