MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 04W (MAYSAK) WARNING NR 33// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 04W (MAYSAK), LOCATED APPROXIMATELY 319 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS PERSISTENT DEEP CONVECTION WITH TIGHTLY-CURVED BANDING WRAPPING INTO AN OBSCURED LOW-LEVEL CIRCULATION CENTER. THE INITIAL POSITION IS BASED ON THE MSI LOOP AND EXTRAPOLATED FROM A MICROWAVE EYE FEATURE ON THE 032326Z 36GHZ GPM MICROWAVE SATELLITE PASS WITH GOOD CONFIDENCE. THE INITIAL INTENSITY OF 75 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF CLOSELY-SPACED DVORAK FIXES FROM ALL REPORTING AGENCIES. UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM IS LOCATED IN AN AREA OF LOW TO MODERATE (10 TO 20 KNOT) VERTICAL WIND SHEAR (VWS) OFFSET BY VIGOROUS POLEWARD OUTFLOW THAT IS EVIDENT ON THE WATER VAPOR IMAGERY. TY MAYSAK IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE DEEP LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 04W WILL CONTINUE TRACKING WEST-NORTHWESTWARD THROUGH TAU 72 UNDER THE STEERING INFLUENCE OF THE STR, MAKING LANDFALL JUST NORTH OF CASIGURAN, PHILIPPINES, SHORTLY BEFORE TAU 24. INCREASING VWS AND LAND INTERACTION WILL GRADUALLY ERODE THE SYSTEM. HOWEVER, IT WILL BE A MINIMAL TYPHOON PRIOR TO LANDFALL AND WILL EMERGE AS A 50-KNOT TROPICAL STORM IN THE SOUTH CHINA SEA BY TAU 36. C. BEYOND TAU 72, A STRONG NORTHEASTERLY COLD SURGE THROUGH THE TAIWAN STRAIT WILL FURTHER ERODE TY MAYSAK AND CONTRIBUTE TO ITS DISSIPATION BY TAU 96. DYNAMIC GUIDANCE REMAINS IN OVERALL GOOD AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK.// NNNN NNNN