WDPN32 PGTW 260300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 21W (MOLAVE) WARNING NR 009// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 21W (MOLAVE), LOCATED APPROXIMATELY 94 NM SOUTHWEST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 17 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS DEEP CONVECTIVE BANDING WRAPPING INTO A DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). A 252215Z SSMIS 91GHZ IMAGE SUGGESTS A SLIGHT WEAKENING TREND DUE TO THE RECENT INTERACTION WITH PANAY ISLAND BUT STILL REVEALS SPIRAL BANDING WRAPPING TIGHTLY INTO THE LLCC. THE INITIAL INTENSITY REMAINS ASSESSED AT 75 KTS BASED ON THE HIGH END OF DVORAK INTENSITY ESTIMATES RANGING FROM T4.0-4.5 (65- 77 KNOTS). A 260000Z ADT ESTIMATE USING THE EMBEDDED CENTER TECHNIQUE YIELDED AN ESTIMATE OF 5.0 (90 KNOTS). ENVIRONMENTAL ANALYSIS REVEALS OVERALL FAVORABLE CONDITIONS CHARACTERIZED BY ROBUST EQUATORWARD OUTFLOW, LOW TO MODERATE (15-20 KTS) VERTICAL WIND SHEAR, AND WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES. TY 21W IS TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 21W IS FORECAST TO TRACK WESTWARD TO WEST-NORTHWESTWARD THROUGH TAU 48 UNDER THE STEERING INFLUENCE OF THE DEEP-LAYERED SUBTROPICAL RIDGE ENTRENCHED TO THE NORTH. AFTER A BRIEF PERIOD OF WEAKENING AS THE SYSTEM TRACKED OVER PANAY ISLAND, TY 21W SHOULD RE- INTENSIFY TO A PEAK INTENSITY OF 95 KNOTS BY TAU 24. THE 25/12Z COAMPS-TC ENSEMBLE INDICATES HIGH POTENTIAL FOR A PEAK OF 90-100 KNOTS WITH A LOW PROBABILITY OF 105 KNOTS. AFTER TAU 48, TY 21W WILL GRADUALLY WEAKEN AS IT APPROACHES EASTERN VIETNAM WITH LANDFALL EXPECTED NEAR TAU 48. MORE SIGNIFICANT WEAKENING WILL OCCUR AFTER TAU 48 AS THE SYSTEM TRACKS INLAND. NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT WITH A 70NM SPREAD IN SOLUTIONS AT TAU 48. C. IN THE EXTENDED RANGE, TY 21W WILL WEAKEN RAPIDLY AS IT TRACKS WESTWARD OVER MOUNTAINOUS TERRAIN WITH DISSIPATION OVER LAND EXPECTED BY TAU 96. WITH THE EXCEPTION OF JGSM (A SOUTHERLY OUTLIER), NUMERICAL MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH TAU 96, LENDING OVERALL HIGH CONFIDENCE IN THE JTWC FORECAST TRACK WHICH IS PLACED NEAR THE MULTI-MODEL CONSENSUS.// NNNN