WDPN31 PGTW 241500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 23W (LEKIMA) WARNING NR 11// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 241200Z9 TO 271200Z2 SEP 01. A. TYPHOON (TY) 23W (LEKIMA), LOCATED APPROXIMATELY 125 NM SOUTH OF TAIWAN, HAS TRACKED WEST-NORTHWESTWARD AT 02 KNOTS DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 241130Z1 INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 77 KNOTS. ANIMATED INFRARED SATELLITE IMAGERY INDICATES THAT THE SYSTEM HAS MAINTAINED INTENSITY OVER THE PAST 6 HOURS WITH SLIGHT WEAKENING IN BOTH EYEWALL CONVECTION AND CONVECTIVE BANDING. B. TY 23W IS CURRENTLY SITUATED WITHIN A WEAKNESS IN THE MID- LEVEL SUBTROPICAL RIDGE AND IS UNDER WEAK STEERING FLOW. THE DYNAMIC AIDS CONSISTING OF THE JMA TYPHOON (JTYM) AND GLOBAL SPECTRAL (JGSM) MODEL, THE UK-MET OFFICE GLOBAL (EGRR), NOGAPS (NGPS), AND THE GEOPHYSICAL FLUID DYNAMICS NAVY (GFDN) MODELS ARE IN GOOD AGREEMENT AND INDICATE A SLOW NORTHWESTWARD TRACK BECOMING MORE WESTWARD AFTER 48 HOURS. THE OFFICIAL FORECAST IS BASED ON PERSISTENCE AND THE NUMERICAL CONSENSUS. C. TY 23W IS EXPECTED TO INTENSIFY SLOWLY THROUGH THE FORECAST PERIOD AS IT TRACKS WITHIN A SLIGHTLY FAVORABLE ENVIRONMENT. D. WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE TROPICAL CYCLONE. FORECAST TEAM: BARLOW/LEEJOICE/WAUGAMAN/SHERRY//