WDPN31 PGTW 101500 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 101200Z4 SEP 02 TO 131200Z7 SEP 02. A. TROPICAL STORM (TS) 23W, APPROXIMATELY 180 NM EAST-SOUTHEAST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 10 KNOTS DURING THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 101130Z6 ENHANCED INFRARED SATELLITE IMAGERY AND RECENT MICROWAVE DATA. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 30 AND 35 KNOTS AND A SHIP REPORT OF 35 KNOTS. ANIMATED WATER VAPOR IMAGERY INDICATES THAT THE SYSTEM HAS CONSOLIDATED 100 NM WEST- NORTHWEST OF THE PREVIOUS WARNING POSITION. A 101148Z5 SSM/I PASS, A 101117Z1 TRMM PASS, AND A 101003Z5 QUIKSCAT PASS SUPPORT THIS RELOCATED POSITION. B. THE LOW TO MID-LEVEL SUBTROPICAL RIDGE OVER EASTERN CHINA IS EXPECTED TO PROPAGATE SLOWLY EASTWARD THROUGH THE PERIOD. TS 23W IS FORECAST TO TRACK NORTHWESTWARD ALONG THE SUBTROPICAL RIDGE THROUGH THE PERIOD. THE AVAILABLE DYNAMIC AIDS, CONSISTING OF NOGAPS, GFDN, NCEP AVIATION, THE JAPANESE GLOBAL AND THE UKMET OFFICE GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THE TRACK, BUT VARY IN SPEED. GFDN KEEPS THE SYSTEM MORE INTENSE AS IT INTERACTS WITH LAND, RESULTING IN A FASTER TRACK SPEED. OUR FORECAST IS BASED ON A BLEND OF ALL AVAILABLE DYNAMIC AIDS. C. TS 23W IS FORECAST TO SLOWLY INTENSIFY IN A FAVORABLE UPPER LEVEL ENVIRONMENT THROUGH 36 HOURS AND THEN WEAKEN AS IT INTERACTS WITH LAND BY 72 HOURS. D. SYSTEM DOES NOT CURRENTLY MEET WIND RADII CRITERIA. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE-SIZED SYSTEM. FORECAST TEAM: WINGEART/LAM/KUMAGA/STATEN// NNNN