WDPN31 PGTW 150300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (HAIYAN) WARNING NR 15// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 150000Z6 TO 180000Z9 OCT 01. A. TYPHOON (TY) 25W (HAIYAN), LOCATED APPROXIMATELY 230 NM SOUTH OF OKINAWA, HAS MOVED WEST-NORTHWESTWARD AT 10 KNOTS DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 142330Z3 INFRARED AND VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 65 TO 90 KNOTS. VISIBLE ANIMATION AND THE LATEST SSM/I PASS DEPICT A DEVELOPING BANDING EYE FEATURE. B. A MID-LEVEL RIDGE SITUATED OVER THE EAST CHINA SEA SHOULD GRADUALLY BEGIN TO WEAKEN AS A MID-LATITUDE TROUGH MOVES OUT OF MONGOLIA. TY 25W SHOULD BEGIN TO DECREASE IN FORWARD MOTION BY MID PERIOD AS THE RIDGE WEAKENS AND SHIFTS EAST. AT THIS POINT, THE SYSTEM IS FORECAST TO SLOWLY TURN NORTHWARD INTO THE CREATED WEAKNESS. LATE IN THE PERIOD, THE SYSTEM IS EXPECTED TO TRACK NORTHEASTWARD TOWARD SOUTHERN JAPAN. THE DYNAMICAL MODELS ARE GROUPED INTO TWO CLUSTERS. THE JMA TYPHOON AND GLOBAL SPECTRAL, UKMET GLOBAL GRID-POINT, COAMPS, REFLECT A RECURVE SCENARIO. HOWEVER, THERE ARE SIGNIFICANT SPEED DIFFERENCES WITH THE JMA GLOBAL REFLECTING THE SLOWEST RECURVE OF THE FOUR. THE GEOPHYSICS FLUID DYNAMICS-NAVY, NOGAPS AND THE NCEP MODELS INDICATE A CONTINUED NORTHWESTWARD TO SOUTHWESTWARD TRACK. THIS SPECIFIC CLUSTER IS REVEALING AGGRESSIVE INTERACTION WITH A MONSOON TROUGH WHICH IS RESULTING IN A UNLIKELY EQUATORWARD BIAS IN THE TRACKS. NOGAPS IS THE MOST HEAVILY DEGRADED WITH A SOUTHWESTWARD TRACK INTO THE SOUTH CHINA SEA. THE FORECAST IS BASED ON PERSISTENCE AND THE FIRST MENTIONED CLUSTER (JMA TYPHOON/GLOBAL, COAMPS, AND THE UKMET). C. TY 25W IS EXPECTED TO INTENSIFY OVER THE NEXT 12 TO 18 HOURS. AFTERWARD, A WEAKENING TREND IS EXPECTED AS A NORTHEAST MONSOON SURGE BEGINS TO AFFECT THE EAST CHINA SEA/OKINAWA OPAREA. D. WIND RADII ANALYSIS IS BASED ON IMAGERY AND SYNOPTIC DATA. FORECAST RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE TROPICAL CYCLONE. FORECAST TEAM: ROBERTS/LEEJOICE/HARRISON/EDBERG//