TY 20W(MINDULLE) CAT3 forecast to remain intense for the next 24h//Arabian Sea: remnants of TC 03B having a new lease of life//Atlantic: still active!

JTWC IS ISSUING 6HOURLY WARNINGS ON TY 20W. 3HOURLY SATELLITE BULLETINS ARE ISSUED ON TY 20W,INVEST 91W AND THE REMNANTS OF TC 03B.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TYPHOON 20W HAS FINALLY CLOCKED OVER TO THE EAST OF NORTH AND ENTERED ITS NORTHEASTWARD LEG. DUE TO THE CLIMATOLOGICALLY ANOMALOUS HEIGHT CENTER OVER THE MARIANAS, THIS IS NOT THE STEREOTYPICAL CASE OF THE STORM ROUNDING THE SOUTHWESTERN FLANK OF THE SUBTROPICAL RIDGE AND ROARING INTO THE MID-LATITUDES. THE MARIANAS HIGH IS BLOCKING THE VORTEX FROM EASTWARD MOVEMENT AS IT DRIFTS POLEWARD UNDER WEAK STEERING. THE RIDGE THAT EXTENDED FROM AN ANTICYCLONE SOUTH OF SHANGHAI ALL THE WAY OVER THE RYUKUS HAS PULLED BACK OVER THE PAST 48 HOURS AND IS ALLOWING THE STORM TO MOVE POLEWARD MORE QUICKLY, BUT A WEDGE OF DRY SUBTROPICAL AIR EXTENDING OVER THE RYUKUS IS KEEPING THE STORM SEPARATED FROM THE MID-LATITUDE WESTERLIES. HENCE, ALTHOUGH THE STORM WILL TRACK POLEWARD AND EVENTUALLY UNDERGO TRANSITION INTO A MID-LATITUDE LOW, IT WILL DO SO AT A SLOWER RATE THAN TYPICAL FOR THE SEASON. IN FACT, PHASE-BASED DIAGRAMS INDICATE THAT THE SYSTEM WILL MAINTAIN ITS WARM CORE EVEN AFTER DEVELOPING THE FRONTAL CHARACTERISTICS OF A WARM OCCLUSION (A SECLUSION AS OPPOSED TO AN OCCLUSION). COUPLED MODELS INDICATE THAT 20W HAS SEEN ITS WARMEST WATERS AND WILL TRACK THROUGH PROGRESSIVELY COOLER SEA WATERS. THE LEISURELY EXTRA-TROPICAL TRANSITION PERIOD WILL COMMENCE AFTER THE VORTEX CROSSES THE 30TH LATITUDE, ROUGHLY AT 30H, AND NOT BE FULLY COMPLETE UNTIL THE STORM IS WELL NORTH OF THE KANTO PLAIN.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOW TYPHOON 20W (MINDULLE) MAINTAINING EYEWALL INTEGRITY OVER THE PAST SIX HOURS, LIKELY DUE TO A BOOST FROM DIURNAL CYCLING. BOTH SUBJECTIVE AND OBJECTIVE DVORAK ASSESSMENTS WERE BEGINNING TO FALL, BUT AFTER 291500Z CLOUD TOPS RESUMED COOLING AND DATA T MEASUREMENTS ACTUALLY ROSE AGAIN. THE EYE REMAINS ROUGHLY 75KM WIDE AND CORE TEMPS ARE HOLDING STEADY, AND BOTH SATCON AND ADT VALUES ARE RISING AGAIN, ALBEIT SLIGHTLY. A 291700Z AMSR2 SERIES DOES SHOW CLEAR INDICATIONS OF DRIER AIR WRAPPING AROUND THE WESTERN SEMICIRCLE BUT THUS FAR THE SYSTEM HAS BEEN ABLE TO ABSORB THE CHALLENGE. THE CURRENT INTENSITY ASSESSMENT IS PREDICATED ON THE JTWC DVORAK ANALYSIS AND SUPPORTED BY SATCON.

MODEL DISCUSSION: TRACK GUIDANCE CONTINUES TO BE OUTSTANDING. THERE ARE NOT EVEN ANY OUTLIERS IN THE MULTI-MODEL CONSENSUS TO COMPLAIN ABOUT. INTENSITY GUIDANCE HAS ALSO CONGEALED WITH EACH SUCCESSIVE MODEL RUN AND THE GAP BETWEEN STATISTICAL-DYNAMICAL AND DETERMINISTIC GUIDANCE HAS CLOSED. THE JTWC FORECAST TRACK STAYS STRAIGHT ON THE MULTI-MODEL CONSENSUS WHILE THE INTENSITY FORECAST STAYS JUST ABOVE THE CONSENSUS AND CLOSER TO THE STATISICAL-DYNAMICAL OUTPUT DURING THE FIRST 36 HOURS, THEN GOES STRAIGHT ON CONSENSUS THROUGH THE DURATION OF THE FORECAST.

THE AREA OF CONVECTION (REMNANTS OF TC 03B) PREVIOUSLY LOCATED NEAR 22.1N 72.4E IS NOW LOCATED NEAR 22.6N 71.4E, APPROXIMATELY 190 KM NORTH OF JAFARABAD, INDIA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND A 291314Z SSMIS 91GHZ SATELLITE IMAGE DEPICT FORMATIVE BAND OF DEEP CONVECTION DEVELOPING ALONG THE WESTERN PERIPHERY OF A LOW LEVEL CIRCULATION CENTER AT THE EDGE OF THE INDIAN SHORELINE. ENVIRONMENTAL ANALYSIS INDICATES AN OVERALL FAVORABLE ENVIRONMENT CHARACTERIZED BY VERY WARM (30-31C) SEA SURFACE TEMPERATURES (SST) AND AN UPPER LEVEL ANTICYCLONE THAT IS ENHANCING EQUATORWARD OUTFLOW. THE CIRCULATION ALSO IS MOVING TOWARDS AN AREA OF LOW VERTICAL WIND SHEAR (VWS). MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH.

GLOBAL MODELS ARE GOOD IN AGREEMENT THAT THE REMNANTS OF TC 03B WILL STRENGTHEN AND CONSOLIDATE AS IT EMERGES OVER THE ARABIAN SEA AND PROPAGATES WEST NORTHWESTWARD.

CURRENT INTENSITY IS 115KNOTS/CAT4 AND IS FORECAST TO PEAK AT 120KNOTS WITHIN THE NEXT 24H.

HU 18L(SAM). TRACK AND INTENSITY GUIDANCE.

CURRENT INTENSITY IS 35KNOTS AND IS FORECAST TO PEAK AT 70KNOTS/CAT 1 BY 01/18UTC

TS 20L(VICTOR). TRACK AND INTENSITY GUIDANCE.

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