WTIO31 PGTW 012100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04A (CHAPALA) WARNING NR 017// RMKS/ 1. TROPICAL CYCLONE 04A (CHAPALA) WARNING NR 017 01 ACTIVE TROPICAL CYCLONE IN NORTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 011800Z --- NEAR 13.3N 53.6E MOVEMENT PAST SIX HOURS - 265 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 110 KT, GUSTS 135 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: 13.3N 53.6E --- FORECASTS: 12 HRS, VALID AT: 020600Z --- 13.2N 51.7E 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 050 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 275 DEG/ 09 KTS --- 24 HRS, VALID AT: 021800Z --- 13.4N 49.9E MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 300 DEG/ 08 KTS --- 36 HRS, VALID AT: 030600Z --- 14.2N 48.4E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 48 HR POSIT: 310 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 031800Z --- 15.1N 47.2E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 325 DEG/ 04 KTS --- 72 HRS, VALID AT: 041800Z --- 16.5N 46.2E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 012100Z POSITION NEAR 13.3N 53.1E. TROPICAL CYCLONE (TC) 04A (CHAPALA), LOCATED APPROXIMATELY 520 NM SOUTHWEST OF MASIRAH ISLAND, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN IMPROVEMENT IN THE OVERALL CONVECTIVE SIGNATURE SURROUNDING AN ENLARGED 20-NM EYE. A 011550Z SSMIS 91GHZ MICROWAVE IMAGE FURTHER SHOWS THE STRENGTHENING WITHIN THE CONVECTIVE CORE WHICH, IN ADDITION TO DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM 102 TO 115 KNOTS, SUPPORTS THE INITIAL INTENSITY BEING INCREASED TO 110 KNOTS. THE CURRENT POSITION IS BASED ON THE EYE FEATURE IN THE EIR LOOP WITH HIGH CONFIDENCE. WATER VAPOR IMAGERY REVEALS AN IMPROVED POLEWARD OUTFLOW CHANNEL WHICH IS SUPPORTING THE INTENSIFICATION IN CENTRAL CONVECTION. SOUTHERLY VERTICAL WIND SHEAR (VWS) REMAINS AT 10 TO 15 KNOTS. TC 04A IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTH. THE CYCLONE WILL CONTINUE TRACKING WESTWARD TOWARDS THE COAST OF YEMEN, MAKING LANDFALL NEAR TAU 36. THE TRACK HAS SHIFTED WESTWARD AS THE STEERING STR STRENGTHENS AND EXTENDS FURTHER WEST. TC CHAPALA WILL BEGIN TO WEAKEN ONCE AGAIN AS THE SYSTEM ENCOUNTERS INCREASED VWS AND DRY AIR. IN ADDITION, LAND INTERACTION WILL BEGIN TO DETERIORATE THE LOW LEVEL STRUCTURE. THE CYCLONE WILL TRACK OVER CENTRAL YEMEN AND FULLY DISSIPATE OVER LAND BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 011800Z IS 28 FEET. NEXT WARNINGS AT 020300Z, 020900Z, 021500Z AND 022100Z.//