MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (CHAN-HOM) WARNING NR 03// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 16W (CHAN-HOM), LOCATED APPROXIMATELY 781 NM SOUTH OF YOKOSUKA, JAPAN, HAS TRACKED WESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) REVEALS FORMATIVE BANDING WRAPPING INTO A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE PARTIALLY EXPOSED LLCC IN THE MSI LOOP AND BANDING FEATURES PRESENT IN A 050650Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY OF 35 KTS IS PLACED WITH FAIR CONFIDENCE AND IS HEDGED ABOVE MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T2.0 (30 KTS, PGTW AND RJTD) AND A CIMSS ADVANCED DVORAK CURRENT INTENSITY ESTIMATE OF T3.2 (32 KTS). TS 16W IS TRACKING SLOWLY ALONG THE PERIPHERY OF A SUBTROPICAL RIDGE POSITIONED TO THE NORTHEAST AND THROUGH AN ENVIRONMENT FAVORABLE FOR FURTHER DEVELOPMENT WITH WITH LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS) AND WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURES (SST). THE SYSTEM IS UNDER SUPPORTIVE UPPER LEVEL EQUATORWARD OUTFLOW HOWEVER CONVERGENT FLOW ALONG THE NORTHWESTERN PERIPHERY OF THE SYSTEM HAS STIFLED DEVELOPMENT OVER THE PAST 6 HOURS. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS CHAN-HOM IS FORECAST TO CONTINUE TRACKING GENERALLY NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STR THROUGH TAU 72. DURING THIS TIME, THE SYSTEM WILL STEADILY INTENSIFY AND REACH A PEAK INTENSITY OF 85 KTS BY TAU 72, LARGELY DUE TO THE CONTINUED LOW VWS AND WARM SSTS. NUMERICAL MODEL TRACK SOLUTIONS HAVE CONTINUED TO CONVERGE WITH A MAXIMUM ACROSS TRACK SPREAD OF 245 NM BY TAU 72. THE UKMET SOLUTIONS REMAIN THE PRIMARY WESTWARD OUTLIERS WITH THE REMAINING MEMBERS OF THE JTWC MULTI-MODEL CONSENSUS CONVERGING ON A MORE EASTWARD TRACK. THE JTWC FORECAST IS LAID NEAR THE EASTWARD SOLUTIONS, WHICH IS NEAR THE JTWC MULTI-MODEL CONSENSUS. DUE TO THE SPREAD IN TRACK GUIDANCE, THERE IS OVERALL FAIR CONFIDENCE IN THIS INITIAL PORTION OF THE JTWC FORECAST TRACK. C. AFTER TAU 72, THE SYSTEM WILL ROUND THE STR AXIS AND BEGIN A GENERALLY NORTHEASTWARD TRACK TOWARDS KYUSHU. TS CHAN-HOM WILL GRADUALLY WEAKEN DURING THIS PERIOD AS VWS BEGINS TO INCREASE TO 20-25 KNOTSS BY TAU 96 AND THEN TO OVER 30 KNOTS BY TAU 120. NUMERICAL MODEL TRACK GUIDANCE DIVERGES SIGNIFICANTLY BY TAU 120 WITH A 600 NM ACROSS TRACK SPREAD AT THIS TIME. DUE TO THIS HIGH DEGREE OF DIVERGENCE IN MODEL SOLUTIONS, THERE IS ONLY POOR CONFIDENCE IN THE REMAINDER OF THE JTWC FORECAST TRACK.// NNNN NNNN