TC 23P(FILI) west of New Caledonia, Invest 95W and Invest 94W: updates at 05/06utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 23P(FILI).

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: IT NO LONGER LOOKS AS THOUGH TC 23P WILL REACH TYPHOON STRENGTH. THE PEAK INTENSITY FORECAST HAS BEEN REDUCED TO 60 KNOTS DUE TO THE WIND SHEAR ASSOCIATED WITH THE SUBTROPICAL WESTERLIES. THE PEAK INTENSITY WILL COME DURING THE NEXT 24 HOURS AS TC 23P, NOW NAMED FILI BY THE FIJI METEOROLOGY AGENCY, MAKES THE TURN TO THE SOUTH-SOUTHEAST AND GETS EVEN BETTER OUTFLOW CONDITIONS EVEN THOUGH IT WILL STILL HAVE TO OVERCOME SIGNIFICANT WINDSHEAR. ALL GUIDANCE SHOWS A GRADUAL INTENSIFICATION THROUGH THE NEXT 24 HOURS THEN A STEADY DECLINE AFTERWARDS. TC FILI WILL BEGIN A SLOW SUBTROPICAL TRANSITION PROCESS AFTER 48H, WHEN SEA SURFACE TEMPERATURES FALL FROM THEIR CURRENT 28C TO 26C AND VERTICAL WIND SHEAR INCREASES TO 25 KNOTS OR GREATER FOR THE DURATION OF ITS LIFE-CYCLE. THERE IS HIGH CERTAINTY THAT THE SYSTEM WILL TAKE A TRACK ALONG THE WESTERN SIDE OF NEW CALEDONIA BUT WINDFIELDS IN THE LEFT FRONT QUADRANT WILL STILL IMPACT THE ISLAND AND PILE UP COASTAL SEAS. A STRONG SURFACE HIGH PRESSURE SYSTEM SUPPORTED BY AN EQUALLY IMPRESSIVE UPPER LEVEL RIDGE WILL CROSS TASMANIA AND ENTER INTO THE CORAL SEA, PREVENTING THE SYSTEM FROM ACCELERATING AND FORCING IT TO GO THROUGH THE SUBTROPICAL TRANSITION PROCESS.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS WESTERLY WIND SHEAR IS REALLY WORKING OVER TC 23P. THE LOW LEVEL CIRCULATION CENTER (LLCC) IS PARTLY EXPOSED WITH ALL DEEP CONVECTION SHEARED EASTWARD. THE INTENSITY TREND HAS FLATTENED OVER THE PAST SIX HOURS. A 042258Z ASCAT PASS CONFIRMS THAT ALTHOUGH THERE IS AN EXTENSIVE FIELD OF 40-45KT WINDS OVER THE NORTHEASTERN QUADRANT, THERE IS A DEARTH OF GALE FORCE WINDS OVER THE NORTHWESTERN QUADRANT. NONETHELESS, THE CORE REMAINS TIGHTLY WOUND AND VIGOROUS DEEP CONVECTION IS STILL PRESENT NEAR THE CORE AND TO ITS SOUTHWEST. SUBJECTIVE DVORAKS AND ADT BOTH AGREE ON A 45-50KT INTENSITY. THOSE ASSESSMENTS ARE CONFIRMED BY THE SCATTEROMETRY. TC 23P HAS MAINTAINED A STEADY 9 KNOT SPEED OF ADVANCE ALONG A SOUTHWESTERLY BEARING BUT IS EXPECTED TO ENTER A TURN TO THE SOUTH-SOUTHEAST MOMENTARILY. A POINT SOURCE TO THE NORTHEAST OF THE LLCC CONTINUES TO PROVIDE ROBUST RADIAL OUTFLOW, BUT WATER VAPOR IMAGERY SHOWS A RATHER SHARP DRY LINE ASSOCIATED WITH A TRANSITIVE MID-LATITUDE TROF IS EXTENDING ALL THE WAY PAST THE TROPIC OF CAPRICORN. ALTHOUGH THAT TROF IS REDUCING SOME OF THE MID-LEVEL MOISTURE ALONG THE WESTERN PERIPHERY, TOTAL PRECIPITABLE WATER ANIMATION CONFIRMS SOME THE LOWER LEVELS NEAR THE CORE ARE MAINTAINING SATURATION.

MODEL DISCUSSION: OTHER THAN UNDER-DOING IT A LITTLE ON THE VERTICAL WIND SHEAR, MODEL GUIDANCE HAS BEEN OUTSTANDING THROUGH THE LIFE CYCLE OF TC 23P THUS FAR. THE JTWC TRACK FORECAST STAYS JUST INSIDE THE MULTI-MODEL CONSENSUS, WEIGHTING THE GFS ENSEMBLE AND DETERMINISTIC TRACKERS. INTENSITY GUIDANCE HEDGES JUST ABOVE THE MEAN DUE TO COAMPS TC RIDING ABOVE THE MEAN AND THE NAVGEM STATISTICAL-DYNAMICAL GUIDANCE PULLING THE MEAN DOWN. ALMOST ALL MODEL TRACKERS INCLUDING GFS LOSE THE VORTEX BEFORE IT REACHES THE SHORES OF THE NORTH ISLAND.

THE AREA OF CONVECTION (INVEST 95W) PREVIOUSLY LOCATED NEAR 4.8N 150.5E IS NOW LOCATED NEAR 4.9N 149.7E, APPROXIMATELY 360 KM SOUTHWEST OF CHUUK, FEDERATED STATES OF MICRONESIA. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY AND A 050334Z AMSR2 89GHZ MICROWAVE PASS REVEALS RAGGED LOW-LEVEL CLOUD LINES WRAPPING INTO AN EXPOSED, BROAD LOW-LEVEL CIRCULATION (LLC) AND FRAGMENTED BANDING CONFINED TO THE NORTHEAST QUADRANT. UPPER-LEVEL CONDITIONS HAVE DEGRADED AS THE UPPER HIGH TO THE NORTH SHIFTED NORTHWEST WITH CONVERGENT FLOW OVER THE NORTHERN PERIPHERY OF THE SYSTEM AND WEAKER DIFFLUENCE TO THE WEST. VERTICAL WIND SHEAR IS UNFAVORABLE AND HAS INCREASED TO 15-25 KNOTS. FURTHERMORE, GFS HAS SLOWED DEVELOPMENT BUT INDICATES INTENSIFICATION TO TROPICAL DEPRESSION STRENGTH BETWEEN 24-72 HOURS. ECMWF INDICATES NO SIGNIFICANT DEVELOPMENT WHILE NAVGEM SHOWS WEAK DEVELOPMENT WITH A WESTWARD TRACK TOWARD THE CENTRAL PHILIPPINES. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 13 TO 18 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED NEAR 11.0N 131.9E IS NOW LOCATED NEAR 8.3N 128.0E, APPROXIMATELY 290 KM EAST-NORTHEAST OF DAVAO, MINDANAO, PHILIPPINES. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY AND A 041939Z SSMIS 91GHZ MICROWAVE IMAGE SHOW WEAK CONVECTIVE BANDING WRAPPING LOOSELY INTO AN ELONGATED, WEAKLY-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC). THE LLC IS EVIDENCED BY A 050126Z ASCAT METOP-C PASS. ENVIRONMENTAL ANALYSIS HAS IMPROVED WITH STRONG DIFFLUENCE ALOFT, LOW (10-15KT) VWS, AND WARM (29-30C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN AGREEMENT REGARDING THE GENERALLY WESTWARD TRACK AND WEAK DEVELOPMENT OF 94W OVER THE NEXT 48 HOURS BEFORE MEANDERING IN A QUASISTATIONARY MANNER OVER THE PHILIPPINES. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 13 TO 18 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.