WDPS31 PGTW 050300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 23P (FILI) WARNING NR 004// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 17.8S 160.4E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 412 NM NORTHWEST OF NOUMEA, NEW CALEDONIA MOVEMENT PAST 6 HOURS: WEST-SOUTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 20 FEET 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. INITIAL WIND RADII BASIS: 042258Z METOP-B. CURRENT STEERING MECHANISM: AN UPPER LEVEL RIDGE CENTERED NEAR 22S 171E IS FORCING THE SYSTEM WESTWARD TOWARDS A WEAKNESS BETWEEN THAT RIDGE AND AN UPPER LEVEL RIDGE EXTENDING OVER CAPE YORK AND THE CORAL SEA, MAKING FOR A NARROW ALLEY FOR TRANSIT TO THE WEST OF NEW CALEDONIA. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS KNES: T3.5 - 55 KTS PHFO: T3.0 - 45 KTS NFFN: T3.0 - 45 KTS CIMSS SATCON: 50 KTS AT 042256Z CIMSS ADT: 49 KTS AT 042340Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 15-20 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG RADIAL OTHER FACTORS: THE STRONG RADIAL OUTFLOW IS BEING IMPINGED OVER THE WESTERN SEMICIRCLE BUT IS VIGOROUS OVER THE EASTERN SEMICIRCLE AND SOUTHERN QUADRANT. ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: HIGH 3. 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 TAU 48, 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. 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. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN