MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (DANAS) WARNING NR 08// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 06W (DANAS), LOCATED APPROXIMATELY 179 NM SOUTHEAST OF TAIPEI, TAIWAN, HAS TRACKED NORTHWARD AT 18 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE CENTRAL CONVECTION CONTINUES TO BE SHEARED EASTWARD OF A MOSTLY OBSCURED LOW LEVEL CIRCULATION (LLC). THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON A RAGGED LLC FEATURE IN THE 172144Z SSMIS AND TRIANGULATED BETWEEN MULTIPLE SURFACE OBSERVATIONS. THE INITIAL INTENSITY OF 35 KNOTS IS BASED THE DVORAK ESTIMATES OF T2.5/35KTS FROM PGTW AND RJTD. UPPER LEVEL ANALYSIS INDICATES THE CYCLONE IS IN AN AREA OF MODERATE (20-25 KNOT) VERTICAL WIND SHEAR (VWS) AND SUBSIDENCE ALONG THE NORTHWEST QUADRANT CAUSED BY AN INDUCED MID-LATITUDE TROUGH OVER TAIWAN. HOWEVER, A STRONG POLEWARD OUTFLOW AND WARM SEA SURFACE TEMPERATURES (SSTS AT 30C) ARE PROVIDING VENTILATION AND FUEL TO THE STRUGGLING CONVECTION. TS 06W IS TRACKING ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 06W WILL CONTINUE TRACKING POLEWARD THROUGH TAU 12 BEFORE BEGINNING A NORTHEASTWARD TURN AS IT ROUNDS THE STR AXIS. THE MARGINAL ENVIRONMENT WILL PROMOTE SLIGHT INTENSIFICATION TO 40 KNOTS AT TAUS 12-24. AFTERWARD, COOLING SSTS, INCREASING VWS, THEN LAND INTERACTION WILL GRADUALLY WEAKEN THE SYSTEM AND BY TAU 72, DISSIPATE OVER THE RUGGED TERRAIN OF SOUTH KOREA EAST OF KUNSAN. NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH MINIMAL SPREADING, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST.// NNNN NNNN