TY 02W(MALAKAS): Rapid Intensification likely next 36hours// TD 03W(MEGI): flooding over parts of the Philippines//Invest 91S, 12/03utc

JTWC IS ISSUING 6HOURLY WARNINGS ON TY 02W(MALAKAS). WARNING 11/FINAL WAS ISSUED ON TD 03W(MEGI) AT 11/09UTC. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON BOTH SYSTEMS. THEY WERE DISCONTINUED ON THE SUBTROPICAL REMNANTS OF 23P(FILI) AT 11/0530UTC.

12/0215UTC.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED VISIBLE SATELLITE IMAGERY DEPICTS SPIRAL CURVED BANDING WRAPPING INTO AN INCREASINGLY WELL DEFINED CONVECTIVE CORE. SHORTLY AFTER THE 00Z SYNOPTIC HOUR, A FORMATIVE CLOUD-FILLED EYE APPEARED, WITH TOWERING CONVECTION WRAPPING AROUND THE CORE INDICATING THAT A LONG-AWAITED RAPID INTESNIFICATION MAY FINALLY BE STARTING. THE INITIAL POSITION WAS BASED ON A BLEND OF AGENCY FIXES FROM PGTW, RJTD, AND RCTP, AND SUPPORTED BY A LOW RESOLUTION 112232Z NOAA-19 AMSU PASS WITH A BANDED CENTER. THE INTENSITY WAS RAISED TO 70 KNOTS AT THE SYNOPTIC TIME, WITH SUBJECTIVE DVORAK ESTIMATES RANGING FROM 65 TO 77 KNOTS BASED ON FINAL-T VALUES OF T4.0 (PGTW AND RJTD) TO T4.5 (RCTP AND KNES). ADT AND SATCON ARE ON THE LOWER END OF THE ENVELOPE AT 59 TO 62 KNOTS, RESPECTIVELY, WHILE AIDT WAS 69 KNOTS AND THE MULTI-PLATFORM SATELLITE WIND ANALYSIS WAS 75 KNOTS. AN 112053Z SMAP PASS WAS SURPRISNGLY LOW AT 50 KNOTS, BUT PROVIDED A BASIS FOR THE 35 KNOT WIND RADII ASSESSMENT. TYPHOON MALAKAS IS ROUNDING A SUB-TROPICAL STEERING RIDGE CENTERED TO THE EAST. UPPER LEVEL WINDS ARE GENERALLY LIGHT AND IN PHASE WITH THE STEERING MOTION, AND DUAL-CHANNEL OUTFLOW CONTINUES TO IMPROVE AS THE NORTHERN EXTENT OF O2W NEARS THE MID-LATITUDE JET. SEA SURFACE TEMPERATURES ARE ESTIMATED TO BE AROUND 28 DEGREES CELSIUS. THESE FACTORS ARE POSITIVE FOR FURTHER DEVELOPMENT.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY MALAKAS WILL CONTINUE TO ROUND THE SUBTROPICAL RIDGE (STR) OVER THE NEXT 12 TO 18 HOURS, AFTER WHICH THE STORM MOTION SHOULD BEGIN TO RECURVE NORTHEASTWARD. FAVORABLE ENVIRONMENTAL CONDITIONS WILL CONTINUE FOR THE NEXT 36 HOURS, ALLOWING FURTHER INTENSIFICATION. THE DEVELOPMENT OF AN EYE IS RAISING THE LIKLIHOOD THAT RAPID INTENSIFICATION (RI) MAY COMMENCE SHORTLY, IF THE NASCENT EYE CAN CONTINUE TO CLEAR OUT. THE GFS AND HWRF BOTH DEPICT RAPID DEEPENING, REACHING MSLP MINIMA OF 947 AND 936 MB, RESPECTIVELY OVER THE NEXT DAY AND A HALF. ADDITIONALLY, SEVERAL RI AIDS WERE TRIGGERED THIS CYCLE, SO THE SHORT-TERM FORECAST INTENSITY TREND WAS INCREASED. A PEAK OF 110 KNOTS/CAT 3 US IS FORECAST AT 36H. THE FORECAST TRACK HAS REMAINED STEADY IN THE CROSS-TRACK DIRECTION, HOWEVER GFS NOW TRACKS 02W MUCH MORE QUICKLY IN THE 96 TO 120 HOUR PERIOD, RESULTING IN A MARKED SHIFT IN THE CONSENSUS MEAN POSITION AT 120H. THE FORECAST POSIT FOR THAT TAU WAS ADJUSTED AHEAD SLIGTHLY, BUT MAY REQUIRE ADDITIONAL ADJUSTMENT IF THIS TREND CONTINUES. MODELS CONTINUE TO INDICATE INCREASING VERTICAL WIND SHEAR WILL OCCUR AFTER 36H. BY 72H, DRY AIR WILL FURTHER DISRUPT THE SYSTEM. EXTRA-TROPICAL TRANSITION (ETT) WILL BEGIN SHORTLY AFTER 72H AND BE COMPLETED BY 120H AS MALAKAS IS FULLY UNDER THE MID-LATITUDE JET. TY 02W IS EXPECTED TO BECOME A STRONG GALE-FORCE COLD-CORE LOW WITH A LARGE WIND FIELD.

MODEL DISCUSSION: DYNAMICAL MODEL TRACK GUIDANCE IS TIGHTLY CLUSTERED IN THE ALONG-TRACK DIRECTION, WITH NO SIGNIFICANT OUTLIERS. HOWEVER, GFS IS INDICATING A FASTER FORWARD MOTION AS THE SYSTEM UNDERGOES ETT. LIKEWISE, INTENSITY GUIDANCE IS IN AGREEMENT WITH INTENSIFICATION OVER THE NEXT 36 TO 42 HOURS.