MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (LINGLING) WARNING NR 06// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 15W (LINGLING), LOCATED APPROXIMATELY 396 NM SOUTH-SOUTHWEST OF KADENA AB, HAS TRACKED NORTHWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS TIGHTLY-CURVED BANDING WRAPPING INTO AN OBSCURED LOW- LEVEL CIRCULATION CENTER (LLCC). A 030716Z SSMIS 37GHZ IMAGE, HOWEVER, DEPICTS A SMALL MICROWAVE EYE FEATURE, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE ALTHOUGH THE WARNING POSITION MAY BE SLIGHTLY (12NM) NNW OF THE ACTUAL POSITION. THE INITIAL INTENSITY IS ASSESSED AT 60 KNOTS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES RANGING FROM T3.5 TO T4.0 (55 TO 65 KNOTS). ENVIRONMENTAL ANALYSIS SHOWS TS 15W IS EXPERIENCING FAVORABLE (5 TO 10 KNOT) VERTICAL WIND SHEAR. THERE IS A STRONG EQUATORWARD OUTFLOW CHANNEL, WHILE THE POLEWARD OUTFLOW CHANNEL CONTINUES TO DEVELOP. SEA SURFACE TEMPERATURES ARE FAVORABLE FOR ADDITIONAL DEVELOPMENT, NEAR 30 DEGREES CELSIUS. TS 15W IS TRACKING NORTHWARD WHILE UNDER THE INFLUENCE OF A SUBTROPICAL RIDGE (STR), LOCATED TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. THE STR LOCATED TO THE EAST WILL BE THE PRIMARY STEERING FEATURE FOR TS 15W THROUGH TAU 72. FAVORABLE SEA SURFACE TEMPERATURES AND FAVORABLE VERTICAL WIND SHEAR WILL ALLOW TS 15W TO QUICKLY INTENSIFY, REACHING 100 KNOTS BY TAU 72. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT THAT TS 15W WILL TRACK NORTHWARD TO NORTH- NORTHEASTWARD THROUGH TAU 36 AND THEN TRACK NORTHWARD. THERE IS A 100NM SPREAD IN MODEL GUIDANCE AT TAU 48 NEAR OKINAWA, THUS, THERE CONTINUES TO BE SOME UNCERTAINTY IN THE SHORT-TERM FORECAST TRACK. ADDITIONALLY, THE 03/00Z ECMWF ENSEMBLE INDICATES A SIMILAR SPREAD IN SOLUTIONS. THE JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH MODERATE CONFIDENCE. C. IN THE LONG TERM, TS 15W WILL CONTINUE TO TRACK NORTHWARD WHILE POSITIONED ALONG THE WESTERN EDGE OF THE STR. AN APPROACHING WEST TO EAST MOVING SHORTWAVE TROUGH WILL HELP TO ACCELERATE TS 15W NORTHWARD. AS TS 15W TRACKS NORTHWARD IT WILL BEGIN EXTRATROPICAL TRANSITION (ETT) BY TAU 96 AND COMPLETE ETT BY TAU 120. DYNAMIC MODEL GUIDANCE HAS BOTH A LARGE ALONG-TRACK AND CROSS-TRACK DISAGREEMENT WITH A SPREAD OF 425 NM. THE JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS WITH MODERATE CONFIDENCE.// NNNN NNNN