WDPN31 PGTW 190300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (SURIGAE) WARNING NR 023// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 02W (SURIGAE), LOCATED APPROXIMATELY 308 NM EAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) INDICATES AN EXTREMELY INTENSE INVARIABLY SYMMETRICAL SYSTEM AND A CENTRAL DENSE OVERCAST (CDO) MAINTAINING WELL-DEFINED ELONGATED 20NM EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE IN THE MSI LOOP AND EXTRAPOLATION FROM AN 182157Z SSMIS 91GHZ IMAGE. THE INITIAL INTENSITY OF 125KTS IS BASED BETWEEN MULTIPLE AGENCY DVORAK FINAL-T ESTIMATES OF T6.5/127KTS (PGTW, KNES, RJTD, AND RCTP); AND THE OBJECTIVE ESTIMATES OF T6.8/135KTS (ADT) AND 144KTS (SATCON), ALL REFLECTING THE EXCEPTIONALLY INTENSE SYSTEM. ANALYSIS INDICATES A SLIGHTLY MORE FAVORABLE ENVIRONMENT WITH THE LOW (5-10KTS) VERTICAL WIND SHEAR (VWS) AND WARM (29-30C) SEA SURFACE TEMPERATURES (SSTS) IN THE PHILIPPINE SEA. THE IMPROVED RADIAL OUTFLOW IS NOW ENHANCING SLIGHT DEVELOPMENT AFTER A MIDLATITUDE TROUGH MIGRATED TO THE NORTHEAST AS SURIGAE TRACKS SLOWLY ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 02W IS CONTINUING TO TRACK NORTH-NORTHWEST IN A WEAK STEERING ENVIRONMENT AS THE STR ELONGATES MERIDIONALLY THROUGH TAU 36 AND 48. THE ALONG TRACK ERROR INCREASES AS IT MOVES NEAR A COL REGION TO THE NORTH AND THEN ROUNDS THE APEX OF THE STR AXIS BY TAU 72. HIGHER VWS, SLIGHTLY COOLER SSTS, AND DIMINISHING OUTFLOW ALOFT WILL BE THE PRIMARY CAUSE TO GRADUAL WEAKENING, DOWN TO 90KTS BY TAU 72. NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A GRADUAL, AND EVEN CROSS-TRACK SPREAD TO 122NM BY TAU 72. THE GFS ENSEMBLE REMAINS THE FAR RIGHT OUTLIER, LENDING FAIR CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK, WHICH IS LAID CLOSE TO AND SLIGHTLY LEFT OF THE MULTI-MODEL CONSENSUS. C. AFTER TAU 72, TY SURIGAE WILL CREST THE AXIS OF THE STR AND ACCELERATE NORTHEASTWARD. ONCE SURIGAE MOVES TOWARD THE HIGHER LATITUDES, IT WILL UNDERGO EXTRATROPICAL TRANSITION AS VWS INCREASES TO +30KTS, SSTS DECREASE TO 24-25C, WHICH WILL ULTIMATELY LEAD TO A DECREASE OF INTENSITY TO 75KTS BY TAU 96. THE NUMERICAL MODELS REMAIN FAIRLY TIGHT IN AGREEMENT AND ONLY SPREAD TO 134NM BY TAU 96, LENDING FAIR CONFIDENCE DURING THIS TIME. HOWEVER, BEYOND TAU 96 ALONG TRACK / CROSS TRACK ERRORS START INCREASING WITH A GREATER SPREAD TO 222NM AS THE SYSTEM CONTINUES EXTRATROPICAL TRANSITION, LENDING LOW CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC TRACK FORECAST.// NNNN