WTIO31 PGTW 011500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04A (CHAPALA) WARNING NR 016// RMKS/ 1. TROPICAL CYCLONE 04A (CHAPALA) WARNING NR 016 01 ACTIVE TROPICAL CYCLONE IN NORTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 011200Z --- NEAR 13.4N 54.6E MOVEMENT PAST SIX HOURS - 270 DEGREES AT 11 KTS POSITION ACCURATE TO WITHIN 010 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 13.4N 54.6E --- FORECASTS: 12 HRS, VALID AT: 020000Z --- 13.4N 52.6E MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 280 DEG/ 09 KTS --- 24 HRS, VALID AT: 021200Z --- 13.7N 50.7E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 290 DEG/ 09 KTS --- 36 HRS, VALID AT: 030000Z --- 14.4N 48.9E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 48 HR POSIT: 315 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 031200Z --- 15.4N 47.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 011500Z POSITION NEAR 13.4N 54.1E. TROPICAL CYCLONE (TC) 04A (CHAPALA), LOCATED APPROXIMATELY 328 NM EAST OF MUKALLA, YEMEN, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS RETAINED A RAGGED 5-NM PINHOLE EYE AND OVERALL CONVECTIVE STRUCTURE. THE INITIAL POSITION IS BASED WITH HIGH CONFIDENCE ON THE 5-NM EYE, ADJUSTED FOR TILT, AND LINED UP WITH THE LOW REFLECTIVITY MICROWAVE EYE IN THE 011018Z AMSU-B PASS. THE INITIAL INTENSITY IS BASED ON AN OVERALL ASSESSMENT OF DVORAK ESTIMATES FROM REPORTING AGENCIES. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS IN AN AREA OF MODERATE 15-KNOT SOUTHERLY VERTICAL WIND SHEAR (VWS) THAT IS PARTIALLY OFFSET BY GOOD RADIAL OUTFLOW. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR). IT IS EXPECTED TO MAINTAIN ITS CURRENT TRACK UP TO TAU 36 AFTER MAKING LANDFALL IN CENTRAL YEMEN NEAR MUKALLA BEFORE MAKING A NORTHWESTWARD TRACK ALONG THE SOUTHWESTERN EDGE OF THE STR. TC CHAPALA WILL RESUME TO A WEAKENING TREND AS DRY AIR EMANATING FROM THE ARABIAN PENINSULA, IN ADDITION TO INCREASING VWS, ERODES THE SYSTEM. THE CYCLONE WILL THEN RAPIDLY DECAY AFTER LANDFALL AND DISSIPATE BY TAU 48 MAINLY DUE TO LAND INTERACTION WITH THE RUGGED AND DRY YEMENI TERRAIN. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 011200Z IS 30 FEET. NEXT WARNINGS AT 012100Z, 020300Z, 020900Z AND 021500Z.//