WDPN31 PGTW 190300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM (TS) 20W/ WARNING NR 02// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 190000Z0 TO 240000Z6 OCT 2003. A. TROPICAL STORM (TS) 20W, LOCATED APPROXIMATELY 850 NM SOUTHWEST OF IWO JIMA, HAS REMAINED QUASI-STATIONARY OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 182330Z7 MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED UPON SATELLITE CURRENT INTENSITY ESTIMATES OF 30 AND 35 KNOTS. ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY REVEALS PERSISTENT DEEP CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER (LLCC). RECENT MICROWAVE IMAGERY REVEALS INCREASED SPIRAL BANDING INTO THE LLCC. TS 20W CONTINUES TO RAPIDLY ORGANIZE AND INTENSIFY. B. TS 20W IS CURRENTLY TRACKING SLOWLY POLEWARD UNDER THE STEERING INFLUENCE OF A LOW TO MID-LEVEL RIDGE LOCATED TO THE NORTHEAST OF THE SYSTEM. THE SYSTEM IS EXPECTED TO CONTINUE TO TRACK SLOWLY NORTHWARD OVER THE NEXT 48 HOURS AS THE RIDGE AXIS SLOWLY BUILDS. AFTER TAU 48 TS 20W WILL THEN TRANSITION TO A MORE NORTHEASTWARD TRACK AS THE STEERING RIDGE REORIENTS AND THE SYSTEM IS INFLUENCED BY AN APPROACHING SHORTWAVE TROUGH. THE AVAILABLE DYNAMIC AIDS CONSISTING OF THE UKMET EGRR, JGSM AND NCEP AVN MODELS ARE IN FAIRLY GOOD AGREEMENT. THE NOGAPS MODEL HAS TS 20W QUASI- STATIONARY THROUGHOUT THE ENTIRE FORECAST PERIOD AND NOT BEING INFLUENCED BY THE APPROACHING SHORTWAVE TROUGH. THIS FORECAST IS BASED ON A CONSENSUS OF AVAILABLE MODELS. C. TS 20W IS EXPECTED TO CONTINUE INTENSIFYING DUE TO ITS POSITION IN AN AREA OF WEAK VERTICAL SHEAR AND AS IT CONTINUES TO EXPERIENCE GOOD DIFFLUENCE ALOFT PROVIDED BY AN EXHAUST CHANNEL INTO AN UPPER LEVEL LOW LOCATED TO THE EAST OF THE SYSTEM. TS 20W IS EXPECTED TO INTENSIFY AT OR SLIGHTLY BELOW A CLIMATOLOGICAL RATE FOR THE ENTIRE FORECAST PERIOD. D. CURRENT WIND RADII ARE BASED ON RECENT QUIKSCAT IMAGERY AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZED SYSTEM. 3. FORECAST TEAM: MOHAMMED/NORAN/DENSON/NUTONGLA/SCHULTZ// NNNN