WTIO32 PGTW 241500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04B (NIVAR) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 04B (NIVAR) WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN NORTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 241200Z --- NEAR 9.8N 82.8E MOVEMENT PAST SIX HOURS - 305 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 060 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 050 KT WINDS - 020 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT REPEAT POSIT: 9.8N 82.8E --- FORECASTS: 12 HRS, VALID AT: 250000Z --- 10.4N 81.9E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 305 DEG/ 06 KTS --- 24 HRS, VALID AT: 251200Z --- 11.1N 80.9E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 315 DEG/ 07 KTS --- 36 HRS, VALID AT: 260000Z --- 12.0N 79.9E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 015 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 310 DEG/ 05 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 261200Z --- 12.7N 79.1E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 310 DEG/ 05 KTS --- 72 HRS, VALID AT: 271200Z --- 13.9N 77.5E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 241500Z POSITION NEAR 9.9N 82.6E. 24NOV20. TROPICAL CYCLONE (TC) 04B (NIVAR), LOCATED APPROXIMATELY 833 NM SOUTH-SOUTHWEST OF KOLKATA, INDIA, HAS TRACKED NORTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS SPIRAL BANDS OF CONVECTION THAT WRAP INTO A LOW LEVEL CIRCULATION CENTER (LLCC) WHICH REMAINS OBSCURED BY DEEP, FLARING CONVECTION. ANALYSIS OF STORM MOVEMENT IN THE MSI LOOP REVEALS THAT THE SYSTEM TRACK HAS SLOWED OVER THE PAST 6 HOURS. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE BANDING CONVECTION FEATURES IN THE MSI LOOP AND IN A 241304Z SSMIS 37 GHZ IMAGE. THE INITIAL INTENSITY OF 50 KTS IS HEDGED BETWEEN A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T3.0 (45 KTS) AND A CIMSS ADVANCED DVORAK TECHNIQUE CURRENT INTENSITY ESTIMATE OF T3.5 (55 KTS). THE SYSTEM IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST AND THROUGH A FAVORABLE ENVIRONMENT WITH LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), ROBUST POLEWARD OUTFLOW AND WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES (SST). TC NIVAR IS FORECAST TO CONTINUE TRACKING GENERALLY NORTHWESTWARD THROUGH THE REMAINDER OF THE FORECAST PERIOD AS A MID-LATITUDE TROUGH APPROACHING FROM THE NORTHWEST DIGS INTO AND WEAKENS THE AFOREMENTIONED STR. OF NOTE, THIS WEAKENING OF THE RIDGE IS EXPECTED TO ALLOW FOR ENHANCED POLEWARD OUTFLOW AND SUBSEQUENT RAPID INTENSIFICATION. AS THE SYSTEM TRACKS OVER THE WARM WATERS OF THE BAY OF BENGAL, IT WILL REACH A PEAK INTENSITY OF 80 KTS BY TAU 36, AT WHICH POINT IT WILL MAKE LANDFALL ALONG THE EASTERN COAST OF INDIA, SOUTH OF CHENNAI. INTERACTION WITH THE UNDERLYING TERRAIN WILL LEAD TO RAPID WEAKENING TO 45 KTS BY TAU 48 AND LEAD TO DISSIPATION OVER LAND BY TAU 72. THE REMNANTS OF TC 04B MAY TRACK OVER THE ARABIAN SEA THEREAFTER, HOWEVER, THERE IS LOW PROBABILITY OF REGENERATION. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 36 WITH A SPREAD OF 70 NAUTICAL MILES AT LANDFALL. THIS AGREEMENT BECOMES POOR THEREAFTER AS THE SPREAD IN MODEL SOLUTIONS INCREASES TO 350 NAUTICAL MILES BY TAU 72. THIS INCREASING SPREAD IS LARGELY DUE TO UKMET MODEL SOLUTIONS WHICH TURN THE SYSTEM SHARPLY TO THE NORTH AT LANDFALL, WITH THE UKMET ENSEMBLE TRACKER BRINGING THE VORTEX BACK OVER THE BAY OF BENGAL BY TAU 60. OVERALL, MODEL GUIDANCE LENDS FAIR CONFIDENCE IN THE JTWC FORECAST TRACK WHICH IS PLACED JUST SOUTH OF THE MULTI-MODEL CONSENSUS TO OFFSET THE UKMET TRACKS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 241200Z IS 18 FEET. NEXT WARNINGS AT 242100Z, 250300Z, 250900Z AND 251500Z. // NNNN