MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 26W (FENGSHEN) WARNING NR 012// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 26W (FENGSHEN), LOCATED APPROXIMATELY 141 NM EAST-SOUTHEAST OF ALAMAGAN, HAS TRACKED WESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES THAT DEEP CONVECTION HAS RE-BUILT OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH IMPROVED DEEP CONVECTIVE BANDING. A 140508Z SSMI 37GHZ COMPOSITE IMAGE DEPICTS A CYAN RING SURROUNDING A MICROWAVE EYE FEATURE, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE AND ALSO MAY SIGNAL A PERIOD OF MORE SIGNIFICANT INTENSIFICATION. THE INITIAL INTENSITY IS ASSESSED AT 55 KNOTS BASED ON A RECENT ASCAT IMAGE SHOWING 50-55 KNOT WINDS OVER THE EASTERN SEMICIRCLE AS WELL AS DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM 3.0 TO 3.5 (45-55 KNOTS). TS 26W IS LOCATED IN AN AREA OF LOW TO MODERATE (10-15 KNOTS) VERTICAL WIND SHEAR, WARM SEA SURFACE TEMPERATURES (28-29C) AND MODERATE WESTWARD AND EQUATORWARD DIFFLUENCE ALOFT. TS 26W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL STEERING RIDGE SITUATED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 26W IS FORECAST TO GRADUALLY RECURVE AROUND THE WESTERN PERIPHERY OF THE BROAD STR THROUGH TAU 72. LOW VERTICAL WIND SHEAR, PASSAGE OVER WARM WATER AND IMPROVING POLEWARD OUTFLOW WILL LIKELY FUEL STEADY INTENSIFICATION THROUGH TAU 48 WITH A PEAK INTENSITY OF 80 KNOTS EXPECTED AT TAU 48. AFTER TAU 48, A WEAKENING TREND WILL BEGIN AS THE SYSTEM ENCOUNTERS INCREASING WESTERLY VERTICAL WIND SHEAR. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THIS OVERALL SCENARIO THROUGH TAU 72, LENDING HIGH CONFIDENCE TO THE INITIAL PORTION OF THE TRACK FORECAST. C. IN THE EXTENDED FORECAST PERIOD, TS 26W IS EXPECTED TO WEAKEN QUICKLY UNDER STRONG WESTERLY VERTICAL WIND SHEAR. THE PRIMARY STEERING INFLUENCE WILL SHIFT TO A LOW-LEVEL HIGH THAT IS FORECAST TO BUILD TO THE NORTH AFTER TAU 72, STEERING TS 26W BACK TO THE WEST. NUMERICAL MODELS AGREE WITH THIS OVERALL FORECAST SCENARIO, BUT VARY IN THEIR DEPICTIONS OF THE RATE OF WEAKENING AND EXACT TRACK DURING THE EXTENDED PERIOD. THE CURRENT TRACK FORECAST LIES NEAR THE MULTI-MODEL CONSENSUS AND THE PREVIOUS JTWC TRACK FORECAST, WITH LOW CONFIDENCE IN THE EXTENDED PERIOD BASED ON THE NOTED MODEL SPREAD.// NNNN NNNN