Super Cyclone 01B(MOCHA) set to make landfall within 24h between SITTWE and COX'S BAZAR//Invest 92S up-graded//1315utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 01B(MOCHA) AND 3HOURLY SATELLITE BULLETINS ON INVEST 92S.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 01B (MOCHA) HAS RAPIDLY INTENSIFIED OVER THE PAST SIX HOURS, HAVING CONSOLIDATED A TIGHT INNER-CORE OF CONVECTION AND ESTABLISHED A WELL-DEFINED EYEWALL. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 19-NM WIDE EYE FEATURE, WITH CENTER TEMPERATURES APPROACHING -10C AND DEEP CONVECTIVE BANDS COMPLETELY SURROUNDING THE INNER CORE. THE 131226Z GMI AND 131156Z SSMIS 89GHZ MICROWAVE IMAGES DEPICTED A SOLID INNER EYEWALL, AS WELL AS A STATIONARY BANDING COMPLEX (SBC) TO THE SOUTH, WHICH IN THE GMI PASS HAS NOW BECOME SEPARATED FROM THE PRIMARY EYEWALL, WHICH MAY HAVE SOME IMPACTS DOWN THE ROAD. ANIMATED WATER VAPOR IMAGERY AND THE CIRA ADVECTED LAYER PRECIPITABLE WATER PRODUCT CONFIRM THE SIGNIFICANT MOISTENING OF THE ENVIRONMENT ON THE NORTH SIDE OF THE SYSTEM, AND THE DRASTIC IMPROVEMENT IN POLEWARD OUTFLOW, AS THE SYSTEM IS NOW SOLIDLY CONNECTED TO OUTFLOW CHANNEL INTO THE RIGHT ENTRANCE REGION OF THE JET MAX OVER SOUTHERN CHINA. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE RECENT MICROWAVE IMAGES NOTED ABOVE. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON A BLEND OF THE AGENCY CURRENT INTENSITY ESTIMATES, ALONG WITH THE DEEP MICRONET (DMN) AND OPEN-AIIR ESTIMATES OF 127 KNOTS AND 132 KNOTS RESPECTIVELY. THE SYSTEM CONTINUES TO TRACK NORTHEASTWARD ALONG THE NORTHWEST SIDE OF THE SUBTROPICAL RIDGE (STR) AND IS PICKING UP SPEED. CONDITIONS REMAIN FAVORABLE FOR INTENSIFICATION, WITH LOW (5-10 KTS) VWS, WARM (30-31C) SSTS AND ROBUST OUTFLOW.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: THERE IS NO SIGNIFICANT CHANGE IN THE TRACK FORECAST, WITH THE SYSTEM EXPECTED TO TRACK NORTHEASTWARD THROUGH THE FORECAST PERIOD. DUE AN INCREASE IN TRACK SPEED, LANDFALL IS EXPECTED SLIGHTLY EARLIER THAN PREVIOUSLY FORECAST, BUT WILL STILL BETWEEN TAUS 12 AND 18 ALONG THE COAST OF MYANMAR, NEAR SITWE. AFTER LANDFALL, THE SYSTEM WILL CONTINUE TO ACCELERATE TOWARDS THE NORTHEAST ALONG THE TIGHT STEERING GRADIENT. IN TERMS OF INTENSITY, THE SYSTEM STILL HAS SOME TIME UNDER NEAR-OPTIMAL CONDITIONS, WHICH WILL SUPPORT ADDITIONAL INTENSIFICATION. SHEAR IS VERY LOW AT PRESENT, ESTIMATED AT BETWEEN 5-10 KNOTS AT BEST. COMBINED WITH THE ZESTY WATERS BELOW AND THE ROBUST OUTFLOW ALOFT, THE SYSTEM IS LIKELY TO MAKE A RUN AT 140 KNOTS OR A BIT HIGHER WITHIN THE NEXT 6 TO 12 HOURS. THE CIMSS M-PERC EYEWALL REPLACEMENT CYCLE (ERC) PREDICTION TOOL IS INDICATING A MODERATE PROBABILITY OF AN ERC AND THE PRESENCE OF THE AFOREMENTIONED SBC FEATURE IN THE MICROWAVE IMAGERY PROVIDES ANOTHER HINT THAT AN ERC COULD BE IN THE OFFING, THOUGH THE EXACT TIMING OF ONSET IS DIFFICULT TO PREDICT. THE FORECAST CALLS FOR A PEAK NEAR 140 KNOTS OR ABOVE AROUND TAU 6, FOLLOWED BY THE ONSET OF ERC WHICH WILL LEAD TO A SLOW WEAKENING BY TAU 12, BACK TO 130 KNOTS. THEREAFTER THE SYSTEM WILL FEEL THE EFFECTS OF SLIGHTLY COOLER SSTS ALONG THE COAST, AS WELL AS AN INCREASE IN MID-LEVEL SHEAR WHICH WILL LEAD TO GENERAL WEAKENING PRIOR TO LANDFALL, THOUGH THE SYSTEM WILL STILL BE AT OR ABOVE 115 KNOTS AT LANDFALL. AFTER LANDFALL THE SYSTEM WILL RAPIDLY WEAKEN DUE TO VERY HIGH SHEAR AND TERRAIN INTERACTION, FULLY DISSIPATING NO LATER THAN TAU 48 OVER NORTHERN MYANMAR.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN VERY GOOD AGREEMENT ON THE NORTHEAST TRACK THROUGH THE FORECAST PERIOD, WITH LESS THAN 50NM SPREAD AT LANDFALL, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. INTENSITY GUIDANCE IS ALSO IN GOOD OVERALL AGREEMENT, WITH THE MAJORITY OF THE CONSENSUS MEMBERS INDICATING A FLAT INTENSITY THROUGH TAU 12, FOLLOWED BY GRADUAL WEAKENING THROUGH LANDFALL AND THEN DRASTIC WEAKENING THROUGH DISSIPATION. THE COAMPS-TC (BOTH NAVGEM AND GFS VERSIONS) ARE THE ONLY MODELS SUGGESTING INTENSIFICATION IN THE NEAR-TERM, THROUGH ABOUT TAU 12, AFTER WHICH THEY REJOIN THE PACK. THE JTWC FORECAST FOLLOWS THE CONSENSUS MEAN, THOUGH AS MENTIONED ABOVE, THE SYSTEM IS LIKELY TO EXPERIENCE SOME ADDITIONAL INTENSIFICATION, AS DEPICTED BY THE COAMPS-TC, IN THE TIMEFRAME BETWEEN THE TAU 00 AND TAU 12 FORECAST POINTS. OVERALL CONFIDENCE IN THE JTWC FORECAST INTENSITY IS HIGH.

THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED NEAR 2.3S 86.6E IS NOW LOCATED NEAR 2.8S 85.6E, APPROXIMATELY 832 NM EAST- NORTHEAST OF DIEGO GARCIA. ENHANCED MULTISPECTRAL SATELLITE IMAGERY AND A 130049Z 91GHZ SSMIS MICROWAVE PASS REVEALS PERSISTENT DEEP CONVECTION TO THE SOUTHWEST OF A FULLY OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC). A 130317Z ASCAT-B PASS HIGHLIGHTS AN OUTER BAND OF 35-40KT WINDS TO THE SOUTHWEST OF THE LLCC UNDER THE FLARING CONVECTION AND A BROAD AND ELONGATED LLCC DISPLACED TO THE NORTHEAST. ENVIRONMENTAL ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT FOR INTENSIFICATION DUE TO LOW-TO- MODERATE (15-20KT) EASTERLY VERTICAL WIND SHEAR, WARM (29-30C) SEA SURFACE TEMPERATURES, AND GOOD EQUATORWARD OUTFLOW. DETERMINISTIC AND ENSEMBLE MODELS AGREE THAT 92S WILL CONTINUE ALONG A WESTWARD TRACK WHILE SLOWLY CONSOLIDATING AND INTENSIFYING OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 27 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

MODELS AGREE THAT 92S WILL CONTINUE ALONG A WESTWARD TRACK WHILE SLOWLY CONSOLIDATING AND INTENSIFYING OVER THE NEXT 24 HOURS.