MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 15W (KALMAEGI) WARNING NR 15// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 15W (KALMAEGI), LOCATED APPROXIMATELY 200 NM NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES THAT THE SYSTEM HAS MAINTAINED A CENTRAL DENSE OVERCAST FEATURE AND DEEP CONVECTIVE BANDING CONFINED PRIMARILY TO THE SOUTHEASTERN QUADRANT. A 130502Z AMSU-B MICROWAVE IMAGE SHOWS TIGHTLY CURVED BANDING AROUND THE LOW LEVEL CIRCULATION CENTER (LLCC) WHILE ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE CONVECTION ASSOCIATED WITH THE SYSTEM HAS SLIGHTLY WARMED OVER THE PAST SIX HOURS. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION AND TRACK MOTION BASED ON THE MICROWAVE IMAGE WHICH IS POSITIONED CLOSE TO THE OVERSHOOTING CLOUD TOPS SEEN IN THE CDO FEATURE. THE INITIAL INTENSITY IS ASSESSED AT 70 KNOTS BASED ON AN AVERAGE OF DVORAK INTENSITY ESTIMATES RANGING FROM 65 TO 77 KNOTS FROM PGTW AND KNES, RESPECTIVELY. UPPER-LEVEL ANALYSIS REVEALS MODERATE (15 TO 25 KNOTS) NORTHEASTERLY VERTICAL WIND SHEAR (VWS) CONTINUES TO HAMPER THE SYSTEM WHILE STRONG EQUATORWARD OUTFLOW AND THE MOTION OF THE SYSTEM OFFSETS THE NEGATIVE EFFECTS OF THE VWS. TY 15W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF AN EAST-WEST ORIENTED SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH OF THE SYSTEM. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 15W IS FORECAST TO ACCELERATE WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STRONG STR THROUGH TAU 72. LANDFALL OVER EASTERN LUZON IS EXPECTED IN THE NEXT SIX HOURS WHICH WILL INDUCE A SHORT LIVED WEAKENING TREND AS THE ROUGH TERRAIN OF LUZON DISRUPTS THE LOW LEVEL INFLOW. AFTER RE-EMERGING ACROSS THE SOUTH CHINA SEA (SCS), THE SYSTEM WILL RE-INTENSIFY DUE TO FAVORABLE ENVIRONMENTAL CONDITIONS IN THE SCS. C. IN THE EXTENDED TAUS, TY 15W IS EXPECTED TO MAINTAIN A PREDOMINANTLY WESTWARD TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD AS THE STR REMAINS ENTRENCHED TO THE NORTH. NEAR TAU 48, TY 15W IS FORECAST TO WEAKEN AS IT APPROACHES AND DRAGS ACROSS THE SOUTHERN COAST OF CHINA AND SHOULD DISSIPATE BY TAU 96 AS IT TRACKS WELL INLAND. DYNAMIC MODEL GUIDANCE (INCLUDING THE MODEL ENSEMBLES) IS IN VERY TIGHT AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK, WHICH IS POSITIONED CLOSE TO THE MULTI- MODEL CONSENSUS.// NNNN NNNN