WNP: TY 02W(SURIGAE) still a CAT4(115knots)/ SIndian: Invest 95S: likely to intensify within the next 24hours(TCFA), 20/09utc update

02W(SURIGAE) AND INVEST 95S. 20/09UTC. 5H LOOP.

02W(SURIGAE). WARNING 28 ISSUED AT 20/09UTC.TY 02W REMAINS IN A GENERALLY FAVORABLE ENVIRONMENT CHARACTERIZED BY LOW (8-12 KTS) AND STRONG POLEWARD AND EQUATORWARD OUTFLOW. SSTS REMAIN GENERALLY WARM, THOUGH RECENT HYCOM MODEL ANALYSIS SUGGESTS SIGNIFICANT UPWELLING, PRIMARILY TO THE SOUTH IN THE STORMS WAKE. HOWEVER, NOW THAT THE SYSTEM HAS PICKED UP FORWARD SPEED ONCE MORE, IT IS MOVING AWAY FROM THE INDUCED POOL OF COOLER WATERS AND INTO A REGION OF 27-28C WATERS. TY SURIGAE IS FORECAST TO TRACK NORTHEASTWARD ALONG THE WESTERN PERIPHERY OF A DEEP SUBTROPICAL RIDGE (STR) THROUGH 36H, THEN ROUND THE RIDGE AXIS AND TURN SHARPLY NORTHEAST AHEAD OF STRONG MID-LATITUDE SHORTWAVE TROUGH MOVING IN FROM THE WEST. BY 72H, SURIGAE WILL BE ON A NEAR EASTWARD COURSE, STEADILY ACCELERATING AS IT BEGINS TO INTERACT WITH THE SUBTROPICAL JET ALOFT. THERE IS NO SIGNIFICANT CHANGE EXPECTED IN THE UPPER-LEVEL ENVIRONMENT, WITH LOW VWS AND STRONG POLEWARD OUTFLOW PERSISTING THROUGH 36H. THE PRIMARY INTENSITY FACTORS ARE THUS THE RELATIVELY MARGINAL SSTS (27C) AND THE LARGE SIZE OF THE CORE AND THE TWO FACTORS TOGETHER SUPPORT A STEADY OR GRADUAL DECREASE IN INTENSITY THOUGH 12H AND THEN STEADIER WEAKENING THROUGH 36H. ONCE THE SYSTEM MAKES THE TURN NORTHEAST BY 48H, STEADY WEAKENING IS FORECAST AS THE SYSTEM ENCOUNTERS STEADILY COOLER SSTS, AT OR BELOW 26C, AND DRAMATICALLY INCREASED MID-LEVEL SHEAR. IN THE LATER PORTION OF THE FORECAST, TY SURIGAE WILL CONTINUE TO ACCELERATE EAST-NORTHEASTWARD AHEAD OF AN ADVANCING MAJOR SHORTWAVE TROUGH AND ALONG THE NORTHERN PERIPHERY OF THE STR TO THE SOUTHEAST. MOST AVAILABLE GUIDANCE SUGGESTS THAT TC 02W WILL NOT BE CAPTURED BY THE PASSING SHORTWAVE, WHICH WILL MISS THE SYSTEM TO THE NORTH, BUT WILL CONTINUE TRACKING EASTWARD AS IT WEAKENS. THE PRIMARY IMPACT OF THE SHORTWAVE WILL BE TO IMPART A STRONG WESTERLY FLOW ALOFT, INCREASING VWS TO ABOVE 50 KNOTS. THE SYSTEM WILL TRANSIT GENERALLY ALONG THE 26C ISOTHERM, BUT DUE TO THE VERY HIGH SHEAR AND THE CONVERGENT NATURE OF THE WESTERLY FLOW ALOFT, WILL STEADILY WEAKEN THROUGH 120H. AS TY 02W MOVES EASTWARD ALONG THE BAROCLINIC ZONE AND DEVELOPS A FRONTAL STRUCTURE, IT IS FORECAST TO BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY 96H.

02W(SURIGAE).NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH 72H AND THE JTWC FORECAST TRACK IS SET WITH HIGH CONFIDENCE. THE INTENSITY FORECAST IS SET ON THE HIGH END OF THE GUIDANCE ENVELOPE AND CLOSELY TRACKS THE HWRF SOLUTION WITH MODERATE CONFIDENCE.NUMERICAL MODEL GUIDANCE IS IN OVERALL GOOD AGREEMENT THOUGH BEGINS TO SHOW SIGNIFICANT SPREAD IN BOTH ALONG AND CROSS-TRACK UNCERTAINTY AFTER 96H DUE TO THE UNCERTAINTY SURROUNDING THE IMPACT OF THE SHORTWAVE TROUGH. THE JTWC FORECAST TRACK IS SET JUST SOUTH FROM THE PREVIOUS FORECAST AND LIES JUST NORTH OF THE MULTI-MODEL CONSENSUS WITH MODERATE CONFIDENCE.

02W(SURIGAE). 20/0503UTC.AMSR2 MICROWAVE PASS CONFIRMED A VERY WELL DEFINED AND INTENSE 55-KM EYEWALL AND THE 37GHZ IMAGE REVEALED A SMALLER AND WEAKER INNER EYEWALL AT ABOUT 28-KM FROM THE CENTER. AMSR2 WINDSPEED MEASUREMENT IS 110 KNOTS.

02W(SURIGAE). 20/0731UTC. DMSP VISIBLE.ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THAT TY SURIGAE CONTINUES TO MAINTAIN A ROUGHLY 55-KM WIDE EYE, THOUGH AT LEAST IN THE VISIBLE AND INFRARED BANDS HAS BECOME SLIGHTLY MORE RAGGED.

02W(SURIGAE). 20/06UTC.

INVEST 95S. TROPICAL CYCLONE FORMATION ALERT.ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 200256Z SSMIS 91GHZ MICROWAVE IMAGE REVEAL FORMATIVE BANDING WITH CYCLING CONVECTION TO THE NORTHEAST AND SOUTH OF THE LOW LEVEL CIRCULATION CENTER (LLCC). INVEST 95S IS IN AN ENVIRONMENT CONDUCIVE FOR INTENSIFICATION, WITH MODERATE EQUATORWARD AND EASTWARD OUTFLOW ALOFT, LOW TO MODERATE (15-20KTS) VERTICAL WIND SHEAR, AND WARM (29-30C) SEA SURFACE TEMPERATURES.

INVEST 95S. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT INVEST 95S WILL TRACK WESTWARD AS IT INTENSIFIES AND PASSES NORTH OF MADAGASCAR OVER THE NEXT 24 HOURS.

INVEST 95S.

INVEST 95S. 20/0623UTC.ASCAT-B BULLSEYE PASS SHOWS A WELL DEFINED LLCC AND AN ASYMMETRIC WIND FIELD, WITH 25-30KT WINDS AND A RELATIVELY SMALLER AREA OF 30-35KT WINDS IN THE SOUTHERN SEMICIRCLE. THE AFOREMENTIONED DATA LEND HIGH CONFIDENCE TO THE ANALYSIS POSITION.

20/0930UTC. THE JTWC IS ISSUING 6HOURLY WARNINGS ON 02W(SURIGAE) AND 3HOURLY SATELLITE BULLETINS. INVEST 95S IS UP-GRADED TO HIGH: WINDS ARE LIKELY TO REACH AT LEAST 35KNOTS CLOSE TO THE CENTER WITHIN 24HOURS. 3HOURLY SATELLITE BULLETINS ARE NOW ISSUED ON 95S.