MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 08W (WIPHA) WARNING NR 03// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 08W (WIPHA), LOCATED APPROXIMATELY 207 NM SOUTH-SOUTHWEST OF HONG KONG, HAS TRACKED NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION BASED ON A PARTIALLY OBSCURED, BUT POORLY-DEFINED, LOW LEVEL CIRCULATION CENTER (LLCC) IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI). THE MSI LOOP ALSO REVEALS THAT THE OVERALL CONVECTIVE SIGNATURE HAS IMPROVED SLIGHTLY, WITH MORE DEEP CONVECTION IN THE NORTHWESTERN QUADRANT, BUT THE SYSTEM STILL LACKS CENTRAL CONVECTION. THE INITIAL INTENSITY HAS INCREASED SLIGHTLY TO 35 KNOTS BASED ON A 310232Z METOP-C ASCAT PASS SHOWING A BROAD SWATH OF 30-35 KNOT WIND BARBS AROUND AN OBLONG LLCC. THIS AGREES WITH A 310740Z ADT ESTIMATE OF 33 KNOTS. ENVIRONMENTAL CONDITIONS ARE SOMEWHAT FAVORABLE WITH FAIR EQUATORWARD OUTFLOW, WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURE, AND LOW (10-15 KT) VERTICAL WIND SHEAR. A WEAK UPPER LEVEL LOW JUST TO THE EAST OF THE SYSTEM IS PROVIDING SUBSIDENCE AND INHIBITING INTENSIFICATION. TS 08W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. THROUGH TAU 72, TS 08W IS EXPECTED TO CONTINUE TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE STR, PASS OVER THE LEIZHOU PENINSULA AROUND TAU 18, ENTER THE GULF OF TONKIN NEAR TAU 24, AND MAKE LANDFALL EAST OF HANOI AROUND TAU 48. THE SUBSIDENCE FROM THE UPPER LEVEL LOW TO THE EAST AND LAND INTERACTION ARE EXPECTED TO LIMIT INTENSIFICATION TO A PEAK OF 35 KNOTS. THE JTWC TRACK FORECAST FOLLOWS JUST AHEAD OF THE CONSENSUS THROUGH TAU 72. BASED ON ALONG TRACK SPREAD IN THE NUMERICAL MODEL GUIDANCE, THERE IS LOW CONFIDENCE FOR THIS PORTION OF THE JTWC TRACK FORECAST. C. AFTER TAU 72, TS 08W WILL CONTINUE INLAND AND DISSIPATE. THE JTWC TRACK FORECAST FOLLOWS CONSENSUS WITH LOW CONFIDENCE BASED ON LARGE SPREAD IN THE MODEL GUIDANCE.// NNNN NNNN