WTIO31 PGTW 190300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 01B (AMPHAN) WARNING NR 012// RMKS/ 1. TROPICAL CYCLONE 01B (AMPHAN) WARNING NR 012 01 ACTIVE TROPICAL CYCLONE IN NORTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 190000Z --- NEAR 15.6N 86.8E MOVEMENT PAST SIX HOURS - 020 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON EYE FIXED BY A COMBINATION OF SATELLITE AND RADAR PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 180 NM SOUTHWEST QUADRANT 185 NM NORTHWEST QUADRANT REPEAT POSIT: 15.6N 86.8E --- FORECASTS: 12 HRS, VALID AT: 191200Z --- 17.4N 87.3E MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT 200 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 015 DEG/ 11 KTS --- 24 HRS, VALID AT: 200000Z --- 19.5N 87.9E MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 015 DEG/ 13 KTS --- 36 HRS, VALID AT: 201200Z --- 22.0N 88.7E MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 015 DEG/ 12 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 210000Z --- 24.3N 89.4E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND RADIUS OF 064 KT WINDS - 000 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 045 DEG/ 07 KTS --- 72 HRS, VALID AT: 220000Z --- 26.3N 91.6E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 190300Z POSITION NEAR 16.0N 86.9E. 19MAY20. TROPICAL CYCLONE 01B (AMPHAN), LOCATED APPROXIMATELY 430 NM SOUTH-SOUTHWEST OF KOLKATA, INDIA, HAS TRACKED NORTH- NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL (MSI) AND ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICT A WEAKENED SYSTEM WITH A UNIFORM CENTRAL DENSE OVERCAST (CDO) AND NO EYE, AT LEAST NOT IN THE VISIBLE OR INFRARED BANDS. THE INITIAL POSITION IN PLACED WITH HIGH CONFIDENCE BASED ON A 182321Z DMSP 89 GHZ COLORIZED IMAGE WHICH SHOWS A NEWLY FORMED PRIMARY EYEWALL SOLIDLY ENTRENCHED ON THE WESTERN SIDE OF THE MICROWAVE EYE AT A RADIUS OF ABOUT 18 NM. THE EYEWALL IS OPEN ON THE EASTERN SIDE OF THE EYE, INDICATIVE OF THE EASTERLY SHEAR AND MID-LEVEL DRY AIR DEPICTED IN MODEL VERTICAL CROSS-SECTIONS THAT ARE IMPACTING THE SYSTEM AND PRECLUDING MORE RAPID CONSOLIDATION OF THE NEW EYEWALL AND COMPLETION OF THE EYEWALL REPLACEMENT CYCLE (ERC). THE INITIAL POSITION IS ALSO SUPPORTED BY LONG-RANGE RADAR DATA FROM INDIA WHICH CAPTURED THE INTENSE WESTERN EYEWALL. THE INITIAL INTENSITY OF 120 KNOTS IS HELD ABOVE THE PGTW CURRENT INTENSITY ESTIMATE OF T5.5 (102 KNOTS), HEDGED UPWARD BASED ON AN ADVANCED DVORAK TECHNIQUE (ADT) CURRENT INTENSITY ESTIMATE OF T6.3 (122 KNOTS). ANALYSIS REVEALS THAT TC 01B IS TRACKING THROUGH A GENERALLY FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (15-20 KNOTS) VWS, VERY WARM (31 DEG CELSIUS) SSTS AND ROBUST POLEWARD AND MODERATE EQUATORWARD OUTFLOW. THE VWS AND MID-LEVEL DRY AIR MENTIONED EARLIER ARE THE PRIMARY CONSTRAINTS ON THE SYSTEM AT THE MOMENT WITH CIMSS SHEAR ESTIMATES CURRENTLY 17.8 KNOTS FROM 150 DEG. TC 01B IS TRACKING NORTH-NORTHEASTWARD ALONG THE WESTERN PERIPHERY OF A DEEP-LAYER NER TO THE EAST AND IS EXPECTED TO CONTINUE THIS MOTION THROUGH THE DURATION OF THE FORECAST PERIOD. WITH THE ERC NEARING COMPLETION AND THE EYEWALL BEGINNING TO REESTABLISH ITSELF IT IS EXPECTED THAT THE SYSTEM WILL EXPERIENCE SOME ADDITIONAL WEAKENING THROUGH TAU 12 BEFORE THE NEW EYE FULLY CONSOLIDATES. ONCE THE EYE BECOMES FULLY ESTABLISHED THE SYSTEM WILL MAINTAIN INTENSITY THROUGH TAU 24 AS THE NEW CORE BECOMES MORE ROBUST AND THE SHEAR VECTOR BECOMES MORE ALIGNED WITH THE STORM MOTION, RESULTING IN LOWER EFFECTIVE SHEAR. AFTER MAKING LANDFALL SOUTH OF KOLKATA NEAR TAU 36 THE SYSTEM WILL RAPIDLY WEAKEN AND THEN DISSIPATE JUST SOUTH OF BHUTAN DUE TO RAPIDLY INCREASING WESTERLY VWS AND TERRAIN INTERACTION. TRACK GUIDANCE REMAINS IN VERY GOOD AGREEMENT THROUGH TAU 48 WITH ONLY MINIMAL SPREAD (25 NM) AT LANDFALL, WITH INCREASING UNCERTAINTY THEREAFTER AS MODELS HAVE DIFFICULTY IN TRACKING THE VORTEX. WITH THE VERY TIGHT PACKING IN THE TRACK GUIDANCE, THERE IS HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. INTENSITY GUIDANCE MOSTLY SHOWS A STEADY WEAKENING TREND THROUGH THE ENTIRE FORECAST, WITH THE EXCEPTION OF COAMPS-TC AND HWRF, BOTH OF WHICH INDICATE A NEAR-TERM STEADY INTENSITY OR EVEN SLIGHT INTENSIFICATION. THE JTWC INTENSITY FORECAST IS HIGHER THAN THE MULTI-MODEL CONSENSUS BUT BELOW THE HWRF THROUGH TAU 24, THEN TRACKS THE HWRF THROUGH THE REMAINDER OF THE FORECAST. DUE TO THE UNCERTAINTY IN THE EVOLUTION OF THE ERC AND THE SHEAR ENVIRONMENT THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 190000Z IS 50 FEET. NEXT WARNINGS AT 190900Z, 191500Z, 192100Z AND 200300Z.// NNNN