WDPN33 PGTW 050300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W WARNING NR 14// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 10W (MALOU), LOCATED APPROXIMATELY 320 NM SOUTH-SOUTHWEST OF CHEJU ISLAND, HAS TRACKED WEST-NORTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS AN EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION FLARING APPROXIMATELY 125 NM TO THE NORTHEAST. THIS CONVECTION MAY BE ASSOCIATED WITH STRONGER GRADIENT FLOW ALONG THE NORTHEASTERN FLANK OF THE LLCC, OR A POSSIBLE DEVELOPING LOW LEVEL CIRCULATION EMBEDDED WITHIN THE BROAD GYRE-LIKE PATTERN. MSI AND A 042317Z SSMIS 91 GHZ MICROWAVE PASS CONFIRM THE LOCATION OF THE EXPOSED LLCC WITH HIGH CONFIDENCE. THE CURRENT INTENSITY IS BASED ON DVORAK ESTIMATES OF 35 KNOTS FROM PGTW, KNES, AND RJTD. 3. FORECAST REASONING. A. THE PEAK INTENSITY HAS BEEN WEAKENED SLIGHTLY FROM THE PREVIOUS FORECAST, HOWEVER THE FUNDAMENTAL PHILOSOPHY OF THE TRACK AND INTENSITY FORECASTS REMAINS THE SAME. B. TS 10W IS CURRENTLY TRACKING WEST-NORTHWESTWARD UNDER THE INFLUENCE OF A LOW TO MID-LEVEL EXTENSION OF THE SUBTROPICAL STEERING RIDGE. THE SYSTEM IS EXPECTED TO INTENSIFY SLIGHTLY AND TRACK POLEWARD AS IT ROUNDS THE SUBTROPICAL RIDGE AXIS. AFTER TAU 48, TS 10W IS FORECAST TO GRADUALLY WEAKEN DUE TO INTERACTION WITH THE MID-LATITUDE WESTERLIES. THERE IS A POSSIBILITY THAT DIRECT CYCLONE INTERACTION (DCI) WITH THE DEVELOPING LOW LEVEL CIRCULATION NORTHEAST OF TS 10W WILL CAUSE THE SYSTEM TO LOOP CYCLONICALLY BEFORE CONTINUING TO TRACK NORTH-NORTHWESTWARD. C. TS 10W IS FORECAST TO MAKE LANDFALL NORTH OF KUNSAN AB, SOUTH KOREA BETWEEN TAU 48 AND TAU 72. AFTER TAU 72, TS 10W WILL BE ABSORBED BY THE BAROCLINIC BOUNDARY TO THE NORTH. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT, WITH THE EXCEPTION OF GFS AND GFDN WHICH LOSE THE SYSTEM AS IT WEAKENS AND TRACKS WESTWARD IN THE LOW LEVEL FLOW. THIS FORECAST FAVORS A TRACK NORTH AND WEST OF MODEL CONSENSUS, BASED ON UPPER AIR ANALYSIS OF THE LOW TO MID-LEVEL STEERING RIDGE AND THE PREVIOUS JTWC FORECAST. // NNNN