MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 33W (USAGI) WARNING NR 21// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 33W (USAGI), LOCATED APPROXIMATELY 295 NM EAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A COMPACT, CONSOLIDATING SYSTEM WITH A PERSISTENT CENTRAL DENSE OVERCAST FEATURE. A 230545Z AMSR2 COMPOSITE 36GHZ IMAGE REVEALS TIGHTLY-CURVED BANDING WRAPPING INTO A SMALL MICROWAVE EYE FEATURE, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 50 KNOTS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES RANGING FROM T3.0 (PGTW) TO T3.5 (RJTD) AS WELL AS A 230133Z BYU HIGH-RESOLUTION ASCAT IMAGE SHOWING 45 TO 50 KNOT WINDS OVER THE NORTHERN SEMICIRCLE. UPPER- LEVEL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (15-20 KT) EASTERLY VERTICAL WIND SHEAR AND VIGOROUS POLEWARD OUTFLOW. TS 33W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. WIND RADII HAVE BEEN ADJUSTED SMALLER BASED ON A DETAILED ANALYSIS OF THE AFOREMENTIONED ASCAT IMAGE. B. TS 33W WILL CONTINUE TRACKING WESTWARD THROUGH TAU 36 ALONG THE SOUTHERN PERIPHERY OF THE STR BUT SHOULD GRADUALLY TURN WEST- NORTHWESTWARD BY TAU 48 AS IT TRACKS ALONG THE SOUTHWESTERN PERIPHERY OF THE STR THROUGH TAU 72. TS 33W IS EXPECTED TO INTENSIFY SLIGHTLY DUE TO FAVORABLE UPPER-LEVEL CONDITIONS AND WARM SST (26- 28C) TO A PEAK INTENSITY OF 55 KNOTS BY TAU 12. TS 33W WILL MAKE LANDFALL BY TAU 36 AND WILL WEAKEN RAPIDLY AS IT TRACKS INLAND WITH DISSIPATION FORECAST BY TAU 72. OVERALL, THERE IS HIGH CONFIDENCE (LOW UNCERTAINTY) IN THE JTWC OFFICIAL FORECAST TRACK, WHICH IS POSITIONED NEAR THE MULTI-MODEL CONSENSUS.// NNNN NNNN