WDPN31 PGTW 111500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W WARNING NR 15//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
   A. TROPICAL STORM (TS) 05W (DIANMU), LOCATED APPROXIMATELY 500 NM 
WEST-SOUTHWEST OF MISAWA, JAPAN, HAS TRACKED EAST-NORTHEASTWARD AT 
17 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE 
IMAGERY INDICATES THAT THE MAJORITY OF THE DEEP CONVECTION HAS 
SHIFTED TO THE EASTERN QUADRANT OF THE STORM. THE LOW-LEVEL 
CIRCULATION CENTER (LLCC) IS LOCATED ALONG THE WESTERN EDGE OF THE 
DEEP CONVECTIVE BANDING BUT HAS BECOME INCREASINGLY DIFFICULT TO 
LOCATE. A 111125Z PARTIAL METOP-A IMAGE SUPPORTS THE CURRENT 
POSITION WITH FAIR CONFIDENCE AND ALSO DEPICTS A DELTA RAIN REGION 
INDICATIVE OF EXTRA-TROPICAL TRANSITION (ETT). TS 05W IS 
ACCELERATING WITHIN THE MID-LATITUDE WESTERLIES AND IS EXPECTED TO 
BECOME FULLY EMBEDDED WITHIN THE NEXT 12-24 HOURS. VERTICAL WIND 
SHEAR (VWS) IS FORECAST TO INCREASE AS THE STORM TRANSLATES 
POLEWARD. SST ARE MARGINAL (24-26C) AND SUPPORT SUSTAINMENT BUT NOT 
INTENSIFICATION OF THE STORM. THE CURRENT INTENSITY IS BASED ON AN 
AVERAGE OF DVORAK ESTIMATES RANGING FROM 35 TO 45 KNOTS AND SURFACE 
OBSERVATIONS. 
3. FORECAST REASONING.
   A. THE FORECAST TRACK PHILOSOPHY HAS NOT CHANGED. THE SYSTEM
CONTINUES TO TRACK CLOSE TO EXPECTATIONS AND THE DYNAMIC AIDS ARE
IN TIGHT AGREEMENT. 
   B. TS 05W IS EXPECTED TO TRACK INTO A REGION OF INCREASING VWS 
AND DECREASING SST. THE GRADUAL DECREASE IN SUPPORT WILL ALLOW THE 
STORM TO MAINTAIN MINIMAL TS STRENGTH UNTIL IT MAKES LANDFALL OVER 
NORTHERN HONSHU. THE SYSTEM IS EXPECTED TO BECOME COMPLETELY 
ABSORBED INTO THE MID-LATITUDE WESTERLIES DURING THE NEXT 24 HOURS. 
TROPICAL STORM 05W IS EXPECTED TO ENCOUNTER INCREASING GRADIENT 
LEVEL BAROCLINICITY AS IT APPROACHES 40N AND IS FORECAST TO COMPLETE 
ETT BEFORE MAKING LANDFALL OVER NORTHERN HONSHU. BECAUSE THE DYNAMIC 
AIDS REMAIN IN VERY TIGHT AGREEMENT THROUGH TAU 36 AND HAVE BEEN 
PERFORMING WELL SINCE THE STORM'S ORIGIN, THE FORECAST CONTINUES TO 
BE BASED ON MODEL CONSENSUS.//
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