WDPN31 PGTW 070300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (AERE) WARNING NR 07// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 22W (AERE), LOCATED APPROXIMATELY 155 NM SOUTHEAST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTI-SPECTRAL SATELLITE IMAGERY INDICATES THE COMPACT SYSTEM HAS IMPROVING CONVECTIVE ORGANIZATION, WITH A WELL DEFINED INTENSE BAND WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC) FROM THE NORTHEAST. THE INITIAL POSITION IS BASED ON A 062345Z SSMIS COLOR COMPOSITE IMAGE, WHICH INDICATES THE POSSIBLE FORMATION OF A MICROWAVE EYE FEATURE, CONSISTENT WITH THE IMPROVING ORGANIZATION. THE INITIAL INTENSITY HAS BEEN INCREASED TO 45 KNOTS BASED ON A PGTW T3.0 DVORAK ESTIMATE, AS WELL AS A 45 KNOT SATCON ESTIMATE, AND ALSO SUPPORTED BY THE AFOREMENTIONED MICROWAVE ASSESSMENT. AERE IS SLOWING AND TURNING SLIGHTLY MORE POLEWARD INTO A COL REGION AS THE STEERING SUBTROPICAL RIDGE (STR) TO THE EAST RECEDES. INTENSIFICATION IS BEING SUPPORTED BY LOW (5-10 KNOT) VERTICAL WIND SHEAR (VWS) AND SEA SURFACE TEMPERATURES OF 29 TO 30 DEGREES CELSIUS, HOWEVER OUTFLOW CONDITIONS WITHIN THE COL ARE MARGINAL. 3. FORECAST REASONING. A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. STEERING FLOW FOR TS 22W WILL CONTINUE TO WEAKEN AS THE STR RECEDES. AERE IS EXPECTED TO BECOME QUASI-STATIONARY WITHIN THE COL, WITH A POSSIBLE SLOW TRACK LOOP OVER THE NEXT TWO DAYS AS STEERING IS SLOWLY TRANSITIONED TO A STR THAT IS EXPECTED TO BUILD IN TO THE WEST AROUND TAU 48. DURING THIS TIME, THE LOW VWS AND SLOW TRACK SPEED OVER VERY WARM WATER SHOULD PROVIDE FOR ADDITIONAL INTENSIFICATION TO A PEAK OF 55 KNOTS. AFTER TAU 48, THE EASTERN EDGE OF THE NEW STR WILL INCREASE VWS AND PROMOTE SUBSIDENCE ALOFT, TRIGGERING A WEAKENING TREND. C. IN THE EXTENDED FORECAST, THE STR OVER CHINA WILL RESULT IN A WEST-SOUTHWESTWARD TRAJECTORY TOWARDS HAINAN. THE LATEST ROUND OF TRACK GUIDANCE INDICATES A SLIGHTLY LONGER QS PERIOD, SO THE EXTENDED TRACK FORECAST HAS BEEN SLOWED SLIGHTLY. THE INCREASED VWS AND UPPER-LEVEL SUBSIDENCE WILL LEAD TO A GRADUAL DECAY, WITH TS 22W DISSIPATING PRIOR TO LANDFALL OVER HAINAN BY TAU 120. DYNAMIC MODEL GUIDANCE REMAINS WIDELY SPREAD DUE TO THE COMPLICATED STEERING ENVIRONMENT AND HIGH UNCERTAINTY ASSOCIATED WITH QS MOTION. THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE.//