02W(MAWAR) forecast to reach CAT 2 US within 48hours approaching the Marianas//TC 19S(FABIEN)// 2109utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TS 02W(MAWAR). 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ARE ISSUED ON TC 19S(FABIEN).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RECENTLY FORMED AND EXPANDING CENTRAL DENSE OVERCAST (CDO) MOSTLY OBSCURING THE LLCC BENEATH. A RECENT 210541Z SSMIS 89GHZ COLOR COMPOSITE MICROWAVE IMAGE REVEALS TWO KEY ELEMENTS ABOUT THE RAPIDLY INTENSIFYING SYSTEM. THE FIRST IS THE IMPROVED CORE CONVECTION, IN BOTH INTENSITY AND ORGANIZATION. THE SECOND ELEMENT IS THE RESULT OF RECENT AND LIKELY SHORT-LIVED DRY AIR ENTRAINMENT INTO THE SOUTHERN PERIPHERY OF THE SYSTEM, WHICH IS PARTIALLY REVEALING THE LLCC. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON MSI AND SSMIS IMAGERY. THE INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A GENERAL CONSENSUS AMONGST AGENCY DVORAK AND AUTOMATED INTENSITY ESTIMATES WHICH INDICATE 55-61KTS. IN THIS STAGE OF TROPICAL CYCLONE DEVELOPMENT, AS SCENE TYPES CHANGE AND THE PATH IS CLEARED FOR AND EYE TO FORM, THE SUBJECTIVE NATURE OF THE DVORAK METHOD IS ON FULL DISPLAY. OUTLIERS IN FINAL INTENSITY ESTIMATE ARE COMMON, HOWEVER THEIR VERACITY SHOULD BE CLOSELY EXAMINED. IN THIS CASE, THE PREPONDERANCE OF INTENSITY ESTIMATES SUPPORTS THE JTWC INITIAL INTENSITY OF 60KTS.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 02W (MAWAR) HAS RAPIDLY INTENSIFIED OVER THE PAST SIX HOURS. AS THE SYSTEM CONTINUES TO PICK UP SPEED UNDER THE STEERING INFLUENCE OF THE NER TO THE EAST, 02W IS FORECAST TO MAINTAIN A GENERALLY NORTH-NORTHWESTWARD TRACK. THE ENVIRONMENT SURROUNDING 02W IS FORECAST TO REMAIN FAVORABLE, CHARACTERIZED BY WARM SSTS AND ROBUST OUTFLOW ALOFT BOTH POLEWARD AND WESTWARD OVERWHELMING THE NEGATIVE AFFECTS OF LIMITED DRY AIR ENTRAINMENT AND MODERATE MID-UPPER LEVEL VERTICAL WIND SHEAR (VWS). AFTER REACHING TYPHOON STRENGTH BY TAU 12, THE SYSTEM WILL CONTINUE TO DEVELOP, FUELED BY THE AFOREMENTIONED ROBUST OUTFLOW ALOFT AND WARM SSTS. NEAR TAU 72, THE NER TO THE EAST REORIENTS AND BUILDS FURTHER NORTHEAST OF THE SYSTEM, FORCING IT TO STEADY UP ON A GENERALLY WEST-NORTHWESTWARD COURSE AFTER PASSING NORTH OF GUAM. BY TAU 120, NOW OVER THE WARM WATERS AND DEEP OCEAN HEAT CONTENT (OHC) OF THE PHILIPPINE SEA, 02W WILL REACH A PEAK INTENSITY OF 110KTS AS IT CONTINUES WEST-NORTHWESTWARD.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH AN EVER SHRINKING CROSS TRACK DISCREPANCY THROUGH TAU 72. AFUM IS NOW THE SOLE OUTLIER INDICATING A WESTWARD APPROACH TO GUAM, WHILE THE BULK OF THE GUIDANCE CLOSELY FOLLOWS THE JTWC FORECAST TRACK. AFTER TAU 72, CROSS TRACK SPREADING REMAINS MINIMAL WHILE ALONG TRACK VARIABILITY IS AN IMPORTANT FACTOR TO CONTINUE MONITORING. AS A RESULT THE JTWC FORECAST TRACK IS PLACED WITH OVERALL HIGH CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS ON GOOD AGREEMENT WITH A BULK OF THE GUIDANCE AS WELL AS SEVERAL RAPID INTENSIFICATION (RI) AIDS INDICATING ROBUST AND PERSISTENT INTENSIFICATION THROUGH TAU 72. AS 02W ENTERS THE PHILIPPINE SEA IN THE EXTENDED TRACK, INTENSIFICATION CONTINUES, SIMPLY AT A REDUCED RATE. FOR THESE REASONS THE JTWC INTENSITY FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS FLARING DEEP CONVECTION PARTIALLY OBSCURING THE LLCC AND SURROUNDING TIGHTLY WRAPPED LOW LEVEL CLOUD LINES. A 210446Z AMSU-B 89GHZ MICROWAVE IMAGE INDICATES AN ELONGATED CIRCULATION WITH DETERIORATING CONVECTION AND RAMPANT DRY AIR ENTRAINMENT. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MSI AND AMSU-B IMAGERY. THE INITIAL INTENSITY OF 35KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A RANGE OF DVORAK AND AUTOMATED INTENSITY ESTIMATES INDICATING 25-45KTS.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 19S (FABIEN) WILL CONTINUE TRACKING GENERALLY POLEWARD OVER THE NEXT 48 HOURS. DURING THIS TIME, THE ENVIRONMENT SURROUNDING THE SYSTEM WILL PROVIDE ENOUGH ENERGY TO MAINTAIN ITS CURRENT INTENSITY, DUE PRIMARILY TO RELATIVELY LOW VERTICAL WIND SHEAR (VWS) AND MARGINALLY FAVORABLE OUTFLOW. THE SYSTEM WILL BECOME MORE ASYMMETRIC AS THE UPPER-LEVEL CIRCULATION TILTS AND DECOUPLES FROM THE LLCC BY TAU 24. THE EXPOSED AND QUICKLY DETERIORATING LLCC WILL THEN TURN SHARPLY WESTWARD AND DISSIPATE BY TAU 72.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN FAIR AGREEMENT WITH A BULK OF THE GUIDANCE GENERALLY FOLLOWING THE JTWC FORECAST TRACK, WITH SEVERAL MEMBERS SHOWING INCREASING CROSS TRACK DISCREPANCY THROUGH THE FORECAST PERIOD. FOR THIS REASON THE JTWC FORECAST TRACK IS PLACED WITH MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS ON GOOD AGREEMENT WITH ALL MEMBERS SHOWING GENERAL STAGNATION THROUGH TAU 48 AND DISSIPATION THEREAFTER. FOR THIS REASON THE JTWC INTENSITY FORECAST IS PLACED WITH HIGH CONFIDENCE.