MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (HAIMA) WARNING NR 09// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 25W (HAIMA), LOCATED APPROXIMATELY 163 NM NORTH OF YAP, HAS TRACKED NORTHWESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS DEEP CONVECTION WRAPPING INTO A NEWLY-DEVELOPED EYE. CONVECTIVE BANDING HAS INCREASED, AND IT APPEARS THAT TY 25W IS BEGINNING A MORE RAPID PERIOD OF INTENSIFICATION. THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE BASED ON EIR. DVORAK INTENSITY ESTIMATES HAVE INCREASED FROM T4.5 (KNES/PGTW) TO T5.5 (PGTW) WITHIN THE LAST 3 HOURS. THUS, THE INITIAL INTENSITY IS SET AT 95 KNOTS. 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 NORTHWESTWARD UNDER THE CURRENT STR TO THE NORTH. ENVIRONMENTAL CONDITIONS WILL FAVOR CONTINUED DEEPENING WITH RAPID INTENSIFICATION 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, LEADING TO SOME SLIGHT WEAKENING AS THE SYSTEM APPROACHES LUZON. C. BEYOND TAU 72, TY 25W WILL CONTINUE TO TRACK TOWARD THE WEST- NORTHWEST TO NORTHWEST. THE INTENSITY FORECAST IN THE LATTER TAUS 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 96, GLOBAL MODEL GUIDANCE DIVERGES, BUT THE SYSTEM WILL LIKELY TURN MORE POLEWARD TOWARDS A BREAK IN THE RIDGE. THE EGRR FALLS TO THE RIGHT, SUGGESTING A TRACK MORE THROUGH THE TAIWAN STRAIT. 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