MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (HAIMA) WARNING NR 10// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 25W (HAIMA), LOCATED APPROXIMATELY 225 NM NORTH-NORTHWEST OF YAP, HAS TRACKED WEST-NORTHWESTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS DEEP CONVECTION WRAPPING INTO AN INTERMITTENT EYE FEATURE. THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE BASED ON EIR AND MULTISPECTRAL SATELLITE IMAGERY. CONVECTIVE BANDING CONTINUES TO GRADUALLY IMPROVE. HOWEVER, AFTER A STEEPER INTENSIFICATION RATE EARLIER TODAY, THE IMPROVEMENT IN CONVECTIVE ORGANIZATION HAS SLOWED SOMEWHAT IN THE LAST 6 HOURS. THE INITIAL INTENSITY IS CONSERVATIVELY INCREASED SLIGHTLY TO 100 KNOTS BASED ON A DVORAK CI OF T5.5 FROM PGTW. TY 25W CONTINUES TO BE IN A FAVORABLE ENVIRONMENT WITH WARM SSTS, EXCELLENT RADIAL OUTFLOW, AND LOW VERTICAL WIND SHEAR. IT IS TRACKING UNDER THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE (STR) TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TY 25W IS EXPECTED TO CONTINUE TRACKING WEST-NORTHWESTWARD TO NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE CURRENT STR TO THE NORTH. ENVIRONMENTAL CONDITIONS WILL FAVOR CONTINUED DEEPENING. ONCE THE DEEP CONVECTION WRAPS AROUND THE LLCC MORE SYMMETRICALLY, A PHASE OF RAPID INTENSIFICATION IS LIKELY. TY 25W IS EXPECTED TO REACH A PEAK OF SUPER TYPHOON INTENSITY IN THE NEXT 1 TO 2 DAYS. THEREAFTER, THE STEERING INFLUENCE WILL TRANSITION TO ANOTHER STR CENTERED NEAR TAIWAN. DURING THIS TRANSITION, THE POLEWARD OUTFLOW MAY BECOME RESTRICTED STARTING AROUND TAU 48, LEADING TO SOME SLIGHT WEAKENING AS THE SYSTEM APPROACHES LUZON. C. BEYOND TAU 72, TY 25W WILL TURN POLEWARD INTO A BREAK IN THE STR. THE INTENSITY FORECAST FOR THIS PERIOD WILL DEPEND ON HOW CLOSE THE SYSTEM GETS TO LUZON. AT THIS TIME, THE INTENSITY FORECAST CONSIDERS THE SCENARIO OF A CLOSE APPROACH BUT NO LANDFALL. AFTER TAU 72, GLOBAL MODEL GUIDANCE DIVERGES, BUT THE SYSTEM WILL LIKELY TURN TOWARD MAINLAND CHINA. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT ONLY UP THROUGH TAU 72, SO THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK UP TO TAU 72 AND LOW CONFIDENCE THEREAFTER.// NNNN NNNN