WDPN32 PGTW 300300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (HAITANG) WARNING NR 08// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 12W (HAITANG), LOCATED APPROXIMATELY 320 NM SOUTH-SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED EAST-NORTHEASTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED, TIGHTLY-WRAPPED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION DISPLACED OVER THE SOUTHERN SEMI-CIRCLE OF THE LLCC DUE TO MODERATE (20 KNOTS) NORTHEASTERLY VERTICAL WIND SHEAR ASSOCIATED WITH TS 11W'S EQUATORWARD OUTFLOW. THIS IMAGERY SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. TS 11W'S CENTER IS CURRENTLY LOCATED ONLY ABOUT 347NM NORTH, HOWEVER, THERE IS LITTLE EVIDENCE OF ANY SIGNIFICANT BINARY INTERACTION OCCURRING. ALTHOUGH DVORAK CURRENT INTENSITY ESTIMATES REMAIN LOWER AT 25 TO 30 KNOTS (1.5 TO 2.0), THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS BASED ON A RECENT ASCAT IMAGE SHOWING 30 TO 35 KNOT WINDS OVER THE WESTERN SEMI-CIRCLE OF THE CIRCULATION, WHICH IS CONSISTENT WITH THE TIGHTLY-WRAPPED SHALLOW BANDING STRUCTURE. TS 12W HAS ACCELERATED AND IS TRACKING EAST- NORTHEASTWARD ALONG THE WESTERN PERIPHERY OF A WEAK, NORTH-SOUTH ORIENTED STEERING RIDGE, HOWEVER, RECENT IMAGERY AFTER 30/00Z INDICATES THE SYSTEM HAS TURNED SHARPLY POLEWARD. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 12W IS EXPECTED TO ACCELERATE NORTHWARD AS TS 11W TRACKS INTO CHINA AND THE STEERING RIDGE BUILDS TO THE EAST. SLIGHT INTENSIFICATION IN THE NEXT 12 HOURS IS FORECAST AS UPPER-LEVEL CONDITIONS IMPROVE (VERTICAL WIND SHEAR CONTINUES TO DECREASE AND POLEWARD OUTFLOW IMPROVES), HOWEVER, SLIGHT WEAKENING NEAR TAU 12 IS EXPECTED AS THE SYSTEM TRACKS OVER THE WESTERN COAST OF TAIWAN. AFTER TAU 24, TS 12W SHOULD TURN NORTH-NORTHWESTWARD AND WEAKEN SIGNIFICANTLY DUE TO LAND INTERACTION. THE SYSTEM IS EXPECTED TO DISSIPATE BY TAU 36. OVERALL, DYNAMIC GUIDANCE IS IN GOOD AGREEMENT AND BINARY INTERACTION IS NOT OCCURRING OR NEGLIGIBLE, THEREFORE THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN