WDPN31 PGTW 182100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (SURIGAE) WARNING NR 022//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 02W (SURIGAE), LOCATED APPROXIMATELY 322 NM EAST OF 
MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 05 KNOTS OVER THE 
PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY 
SHOWS A SYSTEM THAT REMAINS INTENSE, WITH A WARM CENTER AND 
CONVECTIVE TOPS OVER A LARGE SYMMETRICAL CENTRAL DENSE OVERCAST 
MAINTAINING A PINHOLE 8-NM EYE. THE INITIAL POSITION IS PLACED WITH 
HIGH CONFIDENCE BASED ON THE EYE FEATURE IN THE EIR LOOP AND 
EXTRAPOLATION FROM AN 181729Z AMSR2 89GHZ IMAGE. THE INITIAL 
INTENSITY OF 120KTS IS BASED BETWEEN MULTIPLE AGENCY DVORAK FINAL-T 
ESTIMATES RANGING FROM T6.0/115KTS (PGTW, RCTP) TO T6.5/127KTS 
(KNES, RJTD). ANALYSIS INDICATES A SLIGHTLY UNFAVORABLE ENVIRONMENT 
WITH THE LOW (5-10KT) VERTICAL WIND SHEAR (VWS) AND WARM (29-30C) 
SEA SURFACE TEMPERATURES (SSTS) IN THE PHILIPPINE SEA OFFSET BY 
DIMINISHING POLEWARD OUTFLOW CURRENTLY BEING SUPPRESSED BY THE 
MIDLATITUDE TROUGH MIGRATING TO THE NORTH. THE CYCLONE IS TRACKING 
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 WILL CONTINUE TRACKING NORTH-NORTHWEST AS THE STEERING 
STR ELONGATES MERIDIONALLY THROUGH TAU 48, THEREAFTER, THE SYSTEM 
WILL NEAR THE APEX OF THE STR AXIS BY TAU 72. THE DIMINISHING 
OUTFLOW OFFSETTING THE LOW VWS AND WARM SSTS WILL PRIMARILY BE 
RESPONSIBLE FOR ITS GRADUAL WEAKENING, DOWN TO 95KTS BY TAU 72. 
NUMERICAL MODELS ARE IN GOOD AGREEMENT WITH A GRADUAL, AND EVEN 
CROSS-TRACK SPREAD TO 156NM BY TAU 72. THE GFS ENSEMBLE IS 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 STR AXIS, RECURVE AND 
ACCELERATE NORTHEASTWARD. AS SURIGAE MOVES TO HIGHER LATITUDES, THE 
INCREASING VWS AND MUCH COOLER SSTS (24-25C) WILL BEGIN TO RAPIDLY 
DECAY THE INTENSITY TO 65KTS BY TAU 72. SIMULTANEOUSLY, THE SYSTEM 
WILL BEGIN EXTRATROPICAL TRANSITION. THE NUMERICAL MODELS REMAIN 
TIGHT AND SPREAD OUT TO 200NM BY TAU 96, LENDING FAIR CONFIDENCE 
DURING THIS TIME. HOWEVER, BEYOND TAU 96 ALONG TRACK ERRORS 
INCREASE, AS THE SYSTEM BEGINS THE EXTRATROPICAL TRANSITION, LENDING 
LOW CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC TRACK FORECAST.//
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