TS 01W forecast to reach Typhoon Intensity within 48h//TC 01B(REMAL) intensifying to make landfall by 24h//10 Day ECMWF Storm Tracks//2521utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 01W AND ON 01B.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS PERSISTENT CONVECTION OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH CONVECTIVE BANDS WRAPPING IN FROM BOTH THE NORTHWEST AND SOUTHEAST. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON RADAR IMAGERY DEPICTING THE CIRCULATION IN THE VICINITY OF BOHOL ISLAND, PHILIPPINES. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE AGENCY AND OBJECTIVE FIXES LISTED BELOW.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TROPICAL STORM 01W WILL CONTINUE TO ROUND THE STR TO THE EAST OVER THE NEXT 24 HOURS, TRACKING NORTHWESTWARD INITIALLY BEFORE CURVING NORTHEASTWARD. AS THE STR ACQUIRES A NORTHEAST-SOUTHWEST ORIENTATION, THE SYSTEM WILL TRACK NORTHEASTWARD THROUGH THE REMAINDER OF THE FORECAST. TS 01W WILL BEGIN TO INTERACT WITH A MID-LATITUDE TROUGH BETWEEN TAU 96-120 AND COMMENCE EXTRATROPICAL TRANSITION. FOR THE NEXT 24 HOURS THE SYSTEM WILL GRADUALLY INTENSIFY WITH INTERMITTENT LAND INTERACTION WHILE IN THE VICINITY OF THE PHILIPPINE ISLANDS. ONCE COMPLETELY OVER WATER, THE SYSTEM WILL QUICKLY INTENSIFY IN AN ENVIRONMENT OF LOW TO MODERATE SHEAR, GOOD POLEWARD OUTFLOW, AND WARM SEA SURFACE TEMPERATURES. AS THE SYSTEM BEGINS TO INTERACT WITH THE UPPER-LEVEL TROUGH BETWEEN TAU 48 AND TAU 72, AND LATER WITH THE AFOREMENTIONED MID-LATITUDE TROUGH, THE ENVIRONMENT WILL BECOME UNFAVORABLE WITH SHEAR INCREASING SIGNIFICANTLY AND COOLER ALONG-TRACK SSTS POLEWARD OF 26N.

MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE DEPICTIONS OF TS 01W INITIALLY ROUNDING THE STR TO THE EAST VARY. ECMWF DEPICTS A SLOWER TRACK, INTERACTING MORE WITH LAND THAN DEPICTED IN THE GFS SOLUTION, WHICH SPEEDS THE SYSTEM OUT OVER WATER QUICKLY. OVER TIME DIFFERENCES IN NEAR-TERM STORM SPEED BETWEEN ECMWF AND GFS SOLUTIONS, AS WELL AS DIFFERING DEPICTIONS OF THE INTERACTION BETWEEN THE SYSTEM AND A MID-LATITUDE TROUGH BETWEEN TAU 96-120, LEAD TO A VERY LARGE ALONG-TRACK SPREAD, ULTIMATELY 950NM BETWEEN ECMWF AND GFS BY TAU 120. HOWEVER, ENSEMBLE GUIDANCE REVEALS A BROAD ALONG-TRACK SPREAD WITH DISTINCT GROUPINGS OF FASTER AND SLOWER TRACKS IN BOTH THE GEFS AND EC-EPS MEMBERS, HIGHLIGHTING THE UNCERTAINTY OF TRACK SPEEDS WITHIN THE MODEL GUIDANCE. THE INTENSITY GUIDANCE CONSISTENTLY FORECASTS INTENSIFICATION THROUGH TAU 72 AND WEAKENING OCCURRING AFTER TAU 72 DUE TO INTERACTION WITH AN UPPER-LEVEL TROUGH FOLLOWED BY THE MID-LATITUDE TROUGH AND PASSAGE OVER COOLER SSTS.

Ensemble Track Ellipses

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND A 251538Z MHS 89 GHZ MICROWAVE IMAGE DEPICT A SLOWLY CONSOLIDATING, BROAD SYSTEM, WITH INTENSE CONVECTIVE BANDING OVER THE SOUTHERN SEMICIRCLE AND WEAK, FRAGMENTED BANDING OVER THE EASTERN SEMICIRCLE. A 251539Z ASCAT-B BULLSEYE IMAGE SHOWS A DEFINED CIRCULATION CENTER, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE, AND NEAR GALE- FORCE WINDS CONFINED TO THE EASTERN SEMICIRCLE. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE WITH STRONG EQUATORWARD OUTFLOW, LOW VERTICAL WIND SHEAR AND WARM SST VALUES OF 29-30 C. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE RECENT ASCAT DATA AND THE KNES, DEMS DVORAK ESTIMATES. ADDITIONALLY, THE 251730Z ADT, AIDT AND DPRINT OBJECTIVE DVORAK ESTIMATES OF 34-35 KNOTS SUPPORT THE INITIAL INTENSITY ASSESSMENT.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 01B IS FORECAST TO TRACK NORTHWARD THROUGH TAU 24, MAKING LANDFALL NEAR THE BORDER REGION OF INDIA AND BANGLADESH AT TAU 24. DUE TO THE FAVORABLE ENVIRONMENTAL CONDITIONS, THE SYSTEM IS EXPECTED TO INTENSIFY STEADILY THROUGH TAU 24 WITH A PEAK INTENSITY OF 50 KNOTS AT TAU 24. THE SYSTEM WILL LIKELY REMAIN STRONG THROUGH TAU 30 AS IT TRACKS INLAND OVER THE WARM, WET DELTA REGION. AFTER TAU 30, THE SYSTEM WILL TURN NORTHEASTWARD ALONG THE NORTHWEST PERIPHERY OF THE STR WHILE RAPIDLY DISSIPATING. DUE TO THE BROAD NATURE OF THE SYSTEM, HEAVY RAINFALL AND THE STRONGEST WINDS ARE EXPECTED TO BE DISPLACED AWAY FROM THE CENTER.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A CROSS-TRACK SPREAD OF 96 NM AT TAU 24, DIVERGING FURTHER AS THE SYSTEM RECURVES NORTHEASTWARD. RELIABLE INTENSITY GUIDANCE INDICATES A LARGE SPREAD IN PEAK INTENSITY VALUES FROM 50 TO 65 KNOTS. THE JTWC INTENSITY FORECAST IS POSITIONED CLOSE TO THE JTWC INTENSITY CONSENSUS, NEAR THE COAMPS-TC (GFS BOUNDARY CONDITIONS) AND HAFS-A PEAK INTENSITY VALUES. THE 251200Z COAMPS-TC INTENSITY ENSEMBLE INDICATES A LOW PROBABILITY OF RAPID INTENSIFICATION WITH A 20-30 PERCENT PROBABILITY THROUGH TAU 18. THE LATEST EPS AND GEFS ENSEMBLES INDICATE A SIMILAR SPREAD OF SOLUTIONS LENDING MEDIUM OVERALL CONFIDENCE TO THE JTWC TRACK FORECAST.