WTIO31 PGTW 041500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 03B (OCKHI) WARNING NR 020// RMKS/ 1. TROPICAL CYCLONE 03B (OCKHI) WARNING NR 020 01 ACTIVE TROPICAL CYCLONE IN NORTH IO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 041200Z --- NEAR 15.4N 68.9E MOVEMENT PAST SIX HOURS - 020 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT REPEAT POSIT: 15.4N 68.9E --- FORECASTS: 12 HRS, VALID AT: 050000Z --- 16.8N 69.8E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 005 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 030 DEG/ 11 KTS --- 24 HRS, VALID AT: 051200Z --- 18.7N 70.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 015 DEG/ 11 KTS --- 36 HRS, VALID AT: 060000Z --- 20.9N 71.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 010 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 061200Z --- 22.5N 71.9E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 041500Z POSITION NEAR 15.7N 69.1E. TROPICAL CYCLONE 03B (OCKHI), LOCATED APPROXIMATELY 1367 NM NORTH OF DIEGO GARCIA, HAS TRACKED NORTH-NORTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS FLARING CENTRAL CONVECTION BEING SHEARED TO THE NORTHEAST INTO THE LEADING EDGE OF AN APPROACHING TROUGH FROM THE WEST. THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION WHICH IS BASED ON BOTH 37 AND 91 GHZ SSMIS IMAGES FROM 041122Z, SHOWING THE MICROWAVE EYE FEATURE STRUGGLING TO KEEP TOGETHER WITH DEEP CONVECTION PRIMARILY CONFINED TO THE WESTERN SEMICIRCLE AND DISPLACED NORTHEASTWARD. THE INITIAL INTENSITY IS ASSESSED AT 65 KNOTS WHICH IS ON CURRENT INTENSITY DVORAK ESTIMATES OF T4.0 (65 KNOTS) FROM DEMS AND PGTW, COMBINED WITH A 041052Z SATCON ESTIMATE OF 67 KNOTS. UPPER-LEVEL ANALYSIS SHOWS THE POINT SOURCE ALOFT STARTING TO BREAK DOWN AS THE ADVANCING TROUGH INTERACTS WITH THE SYSTEM, AND VERTICAL WIND SHEAR HAS BEEN STEADILY INCREASING OVER THE LAST SIX HOURS AS A RESULT. A DEEP- LAYERED SUBTROPICAL RIDGE TO THE EAST IS STEERING TC 03B ON A COURSE NORTHWESTWARD AND THIS TRACK WILL CONTINUE FOR THE REMAINDER OF THE FORECAST PERIOD. INTERACTION WITH THE APPROACHING TROUGH WILL CONTINUE TO INCREASE WIND SHEAR OVER THE NEXT 48 HOURS, AND IN COMBINATION WITH DRY AIR ENTRAINMENT, WILL SEVERELY WEAKEN TC 03B WHILE OVER OPEN WATER. TC 03B IS EXPECTED TO DISSIPATE BELOW TROPICAL CYCLONE STRENGTH JUST AFTER TAU 36, WITH THE REMNANT LOW MAKING LANDFALL NEAR THE GULF OF KHAMBHAT AROUND TAU 48. DYNAMIC MODEL GUIDANCE SHOWS GOOD AGREEMENT AS THE SYSTEM WEAKENS WITH ONLY MINOR VARIATIONS IN THE EXACT LANDFALL LOCATION. OVERALL THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 041200Z IS 20 FEET. NEXT WARNINGS AT 042100Z, 050300Z, 050900Z AND 051500Z.//