MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (AERE) WARNING NR 10// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 22W (AERE), LOCATED APPROXIMATELY 112 NM EAST- SOUTHEAST OF HONG KONG, HAS TRACKED WESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS CURVED CONVECTIVE BANDING OBSCURING THE QUASI-STATIONARY LOW- LEVEL CIRCULATION CENTER (LLCC). A 071851Z SSMI 85GHZ IMAGE INDICATES AN EXPOSED LLCC WITH TIGHTLY-WRAPPED, SHALLOW BANDING WRAPPING INTO A DEFINED CENTER, WHICH IS POSITIONED JUST SOUTH OF THE LIMITED CONVECTION. THIS IMAGERY SUPPORTS THE CURRENT POSITION WITH GOOD CONFIDENCE. THE CURRENT INTENSITY REMAINS ASSESSED AT 55 KNOTS BASED ON THE LOWER END OF DVORAK ESTIMATES RANGING FROM T3.5 (55 KNOTS) TO T4.0 (65 KNOTS). UPPER-LEVEL ANALYSIS SHOWS A MARGINALLY-FAVORABLE ENVIRONMENT WITH LOW, SOUTHERLY VERTICAL WIND SHEAR (VWS) OFFSET BY GOOD POLEWARD OUTFLOW, AND WARM SST. TS 22W HAS TRACKED QUASI-STATIONARY DUE ITS POSITION WITHIN A WEAK, COMPETING STEERING ENVIRONMENT BETWEEN THE RECEDING SUBTROPICAL RIDGE (STR) TO THE EAST AND A BUILDING STR OVER CHINA. 3. FORECAST REASONING. A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 22W IS FORECAST TO REMAIN WITHIN A COMPETING STEERING ENVIRONMENT OVER THE NEXT TWO DAYS, WHICH WILL PRODUCE A SLOW AND QUASI-STATIONARY MOTION. THE DOMINANT STEERING MECHANISM WILL SLOWLY TRANSITION TO THE STR BUILDING OVER CHINA NEAR TAU 36. DURING THIS TIME, LOW VWS AND SLOW TRACK SPEED OVER VERY WARM WATER WILL ALLOW ADDITIONAL INTENSIFICATION; TS 22W IS EXPECTED TO REACH TYPHOON INTENSITY IN 12 TO 24 HOURS. AFTER TAU 24, THE EASTERN EDGE OF THE BUILDING STR WILL INCREASE VWS AND CAUSE SUBSIDENCE ALOFT, TRIGGERING A GRADUAL WEAKENING TREND. C. IN THE EXTENDED FORECAST, TS 22W WILL ACCELERATE SOUTHWESTWARD TOWARD HAINAN ISLAND AS THE STR OVER SOUTHEAST CHINA BUILDS. 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 COMPLEX STEERING ENVIRONMENT AND HIGH UNCERTAINTY ASSOCIATED WITH THE QUASI- STATIONARY MOTION. THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS WITH LOW CONFIDENCE.// NNNN NNNN