WTIO31 PGTW 191500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 01B (ROANU) WARNING NR 006// RMKS/ 1. TROPICAL CYCLONE 01B (ROANU) WARNING NR 006 01 ACTIVE TROPICAL CYCLONE IN NORTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 191200Z --- NEAR 15.5N 83.0E MOVEMENT PAST SIX HOURS - 065 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT REPEAT POSIT: 15.5N 83.0E --- FORECASTS: 12 HRS, VALID AT: 200000Z --- 16.4N 84.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 050 DEG/ 09 KTS --- 24 HRS, VALID AT: 201200Z --- 17.5N 85.6E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 060 DEG/ 13 KTS --- 36 HRS, VALID AT: 210000Z --- 18.8N 87.9E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 055 DEG/ 14 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 211200Z --- 20.3N 90.4E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 050 DEG/ 15 KTS --- 72 HRS, VALID AT: 221200Z --- 23.9N 95.4E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 191500Z POSITION NEAR 15.7N 83.3E. TROPICAL CYCLONE (TC) 01B (ROANU), LOCATED APPROXIMATELY 645 NM SOUTHWEST OF CHITTAGONG, BANGLADESH, HAS TRACKED EAST-NORTHEASTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES DIMINISHED DEEP CONVECTION OVER THE LOW- LEVEL CIRCULATION CENTER (LLCC) DUE TO DIURNAL TRENDS AND PERSISTENT MODERATE EASTERLY VERTICAL WIND SHEAR (VWS). HOWEVER, A 191237Z SSMIS 37 GHZ IMAGE DEPICTS TIGHTLY-CURVED SHALLOW CONVECTIVE BANDING WRAPPING INTO A DEFINED, BROAD CENTER. THE CURRENT INTENSITY IS HEDGED SLIGHTLY HIGHER THAN DVORAK ESTIMATES OF T3.0 (45 KNOTS) BASED ON OBJECTIVE DVORAK ESTIMATES OF APPROXIMATELY T3.5 (55 KNOTS), CONSISTENT WITH THE WELL-DEFINED LOW-LEVEL STRUCTURE AND RECENT SCATTEROMETER DATA. TC 01B IS TRACKING POLEWARD ALONG THE NORTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) AND IS FORECAST TO ACCELERATE NORTHEASTWARD AS THE STR ERODES AND RE- ORIENTS DUE TO A DEEPENING MIDLATITUDE TROUGH. DYNAMIC GUIDANCE IS IN TIGHT AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. TC 01B IS EXPECTED TO REMAIN WITHIN A MARGINALLY- FAVORABLE ENVIRONMENT WITH PERSISTENT MODERATE VWS HAMPERING CONVECTIVE DEVELOPMENT, OFFSET BY ENHANCED POLEWARD OUTFLOW AND WARM SST. AFTER PEAKING AT TAU 36, TC 01B SHOULD BEGIN TO GRADUALLY WEAKEN AS IT INTERACTS WITH THE MIDLATITUDE WESTERLIES. THE SYSTEM WILL MAKE LANDFALL NEAR TAU 60 AND WILL DISSIPATE OVER LAND NEAR TAU 72. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 191200Z IS 18 FEET. NEXT WARNINGS AT 192100Z, 200300Z, 200900Z AND 201500Z.//