MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (MOLAVE) WARNING NR 16// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 15W (MOLAVE), LOCATED APPROXIMATELY 435 NM EAST OF YOKOSUKA, JAPAN, HAS TRACKED EAST-NORTHEASTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MSI SHOWS A PARTIALLY EXPOSED LLCC WITH DEEP CONVECTION TO THE SOUTHEAST. A 120721Z SSMIS MICROWAVE IMAGE SHOWS A WELL-DEFINED AND ELONGATED LLCC. THE INITIAL POSITION IS BASED ON A PREVIOUS (120407Z) 37V SSMI IMAGE SHOWING A CLEAR LLCC WITH GOOD CONFIDENCE. THE CURRENT INTENSITY IS HELD AT 45 KNOTS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES FROM PGTW AND RJTD. ENVIRONMENTAL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH MODERATE VWS BUT GOOD AND VISIBLE EQUATORWARD OUTFLOW, SPECIFICALLY ON THE EASTERN AND SOUTHERN PERIPHERIES. SSTS REMAIN FAVORABLE AS THEY ARE ABOVE 28 CELSIUS. TS MOLAVE IS TRACKING WITHIN THE WESTERLY FLOW ALONG THE NORTHERN PERIPHERY OF THE STR. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 15W WILL CONTINUE TO TRACK NORTHEASTWARD, UNDER THE INFLUENCE OF BOTH THE STR TO THE SOUTH AND THE MID-LATITUDE WESTERLY FLOW THROUGH THE END OF THE FORECAST PERIOD. ALTHOUGH UPPER LEVEL CONDITIONS ARE MARGINAL, SSTS WILL REMAIN ABOVE 26 CELSIUS THROUGH TAU 12 ALLOWING MINIMAL INTENSIFICATION. HOWEVER, NORTH OF THE 35TH PARALLEL, EXPECT SSTS TO DECREASE SLIGHTLY AND THE SYSTEM TO BEGIN TO DECAY. ADDITIONALLY, INCREASING VWS AS THE SYSTEM STARTS TO BECOME EMBEDDED IN THE BAROCLINIC ZONE WILL AID IN THE REDUCTION OF THE SYSTEM AND WILL SIGNAL THE BEGINNING OF EXTRA-TROPICAL TRANSITION (ETT). EXPECT ETT TO BE COMPLETE BY TAU 48. DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN