MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 30W (NOCK-TEN) WARNING NR 05// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 30W (NOCK-TEN), LOCATED APPROXIMATELY 13 NM WEST-SOUTHWEST OF YAP, HAS TRACKED WEST-NORTHWESTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES DEEP CONVECTION BUILDING OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 220711Z GPM COMPOSITE IMAGE SHOWS MULTIPLE CONVECTIVE BANDS WRAPPING INTO THE LLCC WITH A DEFINED CENTER POSITIONED JUST TO THE WEST OF YAP, WHICH SUPPORTS THE CURRENT POSITION WITH GOOD CONFIDENCE. THE CURRENT INTENSITY IS ASSESSED AT 40 KNOTS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES RANGING FROM T2.5 (35 KNOTS) TO T3.0 (45 KNOTS). TS NOCK- TEN IS LOCATED IN A VERY FAVORABLE ENVIRONMENT WITH LOW (5-10 KNOTS) VERTICAL WIND SHEAR (VWS), GOOD DIVERGENT OUTFLOW, AND VERY WARM SEA SURFACE TEMPERATURES. TS 30W IS TRACKING WEST-NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 30W WILL TRACK WEST-NORTHWESTWARD TO WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE STEERING STR THROUGHOUT THE FORECAST PERIOD. TS NOCK-TEN WILL CONTINUE TO INTENSIFY UNDER THE VERY FAVORABLE ENVIRONMENTAL CONDITIONS WITH THE POTENTIAL FOR A PERIOD OF RAPID INTENSIFICATION (WITHIN THE NEXT 48 HOURS), DUE TO HIGH OCEAN HEAT CONTENT, PRIOR TO REACHING THE EASTERN COAST OF THE PHILIPPINES. WITH THE EXCEPTION OF GFDN, DYNAMIC MODEL VORTEX TRACKERS ARE IN TIGHT AGREEMENT WITH A 55-NM SPREAD IN SOLUTIONS AT TAU 72. GFDN, WHICH INDICATES SIGNIFICANTLY LOWER INTENSITY VALUES, IS ERRONEOUSLY DRIVING THE SYSTEM SOUTHWESTWARD WITHIN THE LOW-LEVEL FLOW AFTER TAU 48. OVERALL, THERE IS HIGH CONFIDENCE DURING THIS PORTION OF THE FORECAST. C. AFTER TAU 72, TS 30W IS FORECAST TO TURN SLIGHTLY WEST- NORTHWESTWARD AS IT APPROACHES THE WESTERN EDGE OF THE STR. HOWEVER, THE SYSTEM IS NOT EXPECTED TO RE-CURVE DUE TO THE PRESENCE OF VIGOROUS NORTHEAST MONSOON FLOW OVER THE SOUTH CHINA SEA. TS 30W WILL WEAKEN AS IT TRACKS ACROSS THE PHILIPPINES BUT SHOULD MAINTAIN MINIMAL TYPHOON STRENGTH AS IT RE-EMERGES OVER WATER NEAR TAU 96. ADDITIONAL WEAKENING IS EXPECTED AS THE SYSTEM ENCOUNTERS COOLER, DRIER AIR AND INCREASING VWS ASSOCIATED WITH THE NORTHEAST SURGE. DYNAMIC MODEL VORTEX TRACKERS DIVERGE SLIGHTLY IN THE EXTENDED PERIOD WITH A SPREAD IN SOLUTIONS OF 150-NM AT TAU 120. DUE TO THE IMPROVED AGREEMENT IN THE DYNAMIC GUIDANCE, THERE IS NOW HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN