Typhoon 28W(RAI) crossing multiple islands and then Palawan within 24hours, 2nd intensity peak forecast over the SCS

16/1450UTC.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY 28W WILL CONTINUE TRACKING WEST-NORTHWEST OVER MULTIPLE PHILIPPINE ISLANDS AND THE ISLAND OF PALAWAN THROUGH THE NEXT 24 HOURS AND SLIGHTLY DECREASE INTENSITY AS IT INTERACTS WITH THE ISLANDS. HOWEVER, ONCE THE STORM MOVES WEST OF PALAWAN, IT WILL BEGIN TO TAP INTO A STRONGER POLEWARD OUTFLOW CHANNEL AND REACH A PEAK INTENSITY OF 105 KNOTS/CAT 3 BY 48H JUST AS IT BEGINS TO TURN NORTH. BY 72H TY RAI WILL ENCOUNTER A NORTHEAST SURGE, ROUND THE RIDGE AXIS AND INDUCT COLD AIR INTO THE SYSTEM. THE COLD DRY AIR AND HIGHER VWS WILL RAPIDLY ERODE THE CORE OF THE SYSTEM THROUGH THE END OF THE FORECAST PERIOD.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS AN EMBEDDED CENTER WITH A SLIGHTLY WEAKENING SYSTEM MOVING QUICKLY OVER MULTIPLE PHILIPPINE ISLANDS. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE EMBEDDED CENTER AND A 161254Z ASCAT METOP-B 25KM IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH LOW CONFIDENCE AT 115 KNOTS/CAT 4, BASED LOWER THAN THE ADVANCED DVORAK TECHNIQUE (ADT), WHICH IS HELD BY CONSTRAINTS OF 135 KNOTS, THE SATELLITE CONSENSUS (SATCON) OF 143 KNOTS, AND MULTIPLE AGENCY FIXES LISTED BELOW. THE ENVIRONMENT REMAINS FAVORABLE OVERALL, WITH VERY WARM SSTS, HIGH OHC, GOOD POLEWARD AND EQUATORWARD OUTFLOW, BEING SLIGHTLY OFFSET BY MODERATE TO STRONG EASTERLY VWS.

MODEL DISCUSSION: TRACK GUIDANCE REMAINS IN TIGHT AGREEMENT, WITH A MERE SPREAD OF ONLY 185KM AT 72H. THE CROSS-TRACK SPREAD INCREASES TO 500KM BY 120H BETWEEN THE GFS ON THE RIGHT AND AFUM ON THE LEFT OF THE GUIDANCE ENVELOPE. THE JTWC FORECAST REMAINS CONSISTENT WITH THE PREVIOUS FORECAST AND CLOSELY TRACKS THE CONSENSUS MEAN THROUGH 36H, THEN SLIGHTLY TO THE LEFT OF THE MEAN THROUGH 120H. INTENSITY GUIDANCE IS IN FAIR AGREEMENT AS WELL, WITH ALL MEMBERS INDICATING IMMEDIATE WEAKENING FROM STARTING TAU WITH HWRF REMAINING THE MOST SUBDUED, REDUCING THE SYSTEM DOWN TO 70 KNOTS BY 24H, WHILE COAMPS-TC BOLSTERS THE SYSTEM TO A SECOND PEAK OF 110 KNOTS/CAT 3 IN THE SOUTH CHINA SEA. THE JTWC FORECAST REMAINS 10 KNOTS ABOVE THE CONSENSUS MEAN, BUT LOWER THAN THE COAMPS-TC THROUGH 36H, THEN SLIGHTLY BELOW THE COAMPS-TC BUT ABOVE THE REMAINDER OF THE GUIDANCE THROUGH 120H. CONFIDENCE IN THE TRACK REMAINS HIGH FOR THE BEGINNING OF THE TRACK, THEN TRENDS TOWARDS MEDIUM IN THE LONG-RANGE AS THE ALONG TRACK SPEED CHANGES AFTER THE SYSTEM ENCOUNTERS THE COLD DRY AIR AND ROUNDS THE RIDGE AXIS. CONFIDENCE IN THE INTENSITY IS LOW DUE TO UNCERTAINTIES OF THE IMPACT OF THE LAND INTERACTION AND WHETHER THE SYSTEM WILL QUICKLY INTENSIFY IN THE SOUTH CHINA SEA.

THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED NEAR 4.8N 107.1E IS NOW LOCATED NEAR 4.4N 104.5E APPROXIMATELY 345KM NM NORTH-NORTHEAST OF SINGAPORE. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A MUDDLED MESS OF THUNDERSTORMS ABOVE AND EAST OF THE MALAY PENINSULA. EASTERN SHEAR FROM THE OUTFLOW OF 28W (TYPHOON RAI) IS APPLYING SIGNIFICANT PRESSURE TO THE CONVECTION ASSOCIATED WITH 97W, PARTIALLY EXPOSING THE LOW LEVEL CIRCULATION CENTER (LLCC). HOWEVER, A 161500Z SHIP OBSERVATION JUST SOUTH OF THE LLCC REPORTED 23KTS FROM THE WEST-SOUTHWEST. ANALYSIS INDICATES THE ENVIRONMENT IS OVERALL FAVORABLE WITH WARM SEA SURFACE TEMPERATURES AND FLOURISHING POLEWARD OUTFLOW, OFFSET BY THE AFOREMENTIONED MODERATE SHEAR (15-20 KTS). DYNAMIC MODELS INDICATE 97W WILL TRACK WEST OVER THE MALAYAN PENINSULA AND INTO THE STRAIT OF MALACCA. AS IT STANDS, INTENSIFICATION WILL BE MINIMAL BEFORE THE SYSTEM MOVES OVER LAND. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 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 HIGH.

JTWC IS ISSUING 6HOURLY WARNINGS ON 28W(RAI). 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 28W AND INVEST 97W.