WDPN33 PGTW 100900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 26W (TORAJI) WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 15.2N 125.2E
   INITIAL INTENSITY: 65 KTS
   GEOGRAPHIC REFERENCE: 246 NM EAST OF MANILA, PHILIPPINES
   MOVEMENT PAST 6 HOURS: WESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 26 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
EASTERLY VERTICAL WIND SHEAR (VWS) HAS INCREASED OVER THE PAST 12
HOURS AND IS CLEARLY EVIDENT ON ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY. EIR IMAGERY NOW INDICATES A MORE ASYMMETRIC
CENTRAL DENSE OVERCAST WITH A TIGHT THERMAL GRADIENT OVER THE
EASTERN QUADRANT. ADDITIONALLY, A 100437Z AMSR2 89GHZ MICROWAVE
IMAGE SHOWS A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER TUCKED 
UNDER THE EASTERN EDGE OF THE CENTRAL CONVECTION, WITH TIGHTLY-CURVED
BANDING. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED 
ON THE AMSR2 IMAGE. DESPITE THE INCREASED EASTERLY VWS, STRONG RADIAL 
OUTFLOW AND VERY HIGH OCEAN HEAT CONTENT VALUES CONTINUE TO AID IN 
INTENSIFICATION ALBEIT AT A SLOWER RATE. THE INITIAL INTENSITY OF 65 
KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE PGTW AND KNES 
DVORAK ESTIMATES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) 
ENTRENCHED TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T4.0 - 65 KTS
   RJTD: T3.5 - 55 KTS
   KNES: T4.0 - 65 KTS
   CIMSS SATCON: 80 KTS AT 100530Z
   CIMSS ADT: 79 KTS AT 100530Z
   CIMSS AIDT: 75 KTS AT 100530Z
   CIMSS D-MINT: 59 KTS AT 100633Z
   CIMSS D-PRINT: 56 KTS AT 100700Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 15-20 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TYPHOON (TY) 26W IS EXPECTED TO TRACK WEST-
NORTHWESTWARD THROUGH TAU 12 WITH A SHORT PERIOD OF RAPID 
INTENSIFICATION EXPECTED AS VWS RELAXES. PEAK INTENSITY SHOULD BE
NEAR 85 KNOTS BUT COULD POTENTIALLY JUMP HIGHER IF THE SYSTEM
QUICKLY REORGANIZES. AFTER LANDFALL NEAR TAU 18, THE SYSTEM WILL
WEAKEN SIGNIFICANTLY WHILE CROSSING THE MOUNTAINOUS REGION OF
LUZON. AFTER TAU 24, TY 26W WILL TRACK WEST-NORTHWESTWARD THROUGH
TAU 72 WITH STEADY WEAKENING DUE TO DRY AIR ENTRAINMENT AND COOLING
SST VALUES, PARTICULARLY AFTER TAU 48. IN THE EXTENDED PERIOD, THE
SYSTEM WILL SLOW, AS THE STR WEAKENS, THEN WEAKEN QUICKLY AND TURN
WESTWARD TO WEST-SOUTHWESTWARD UNDER LOW-LEVEL STEERING. THERE IS
INCREASING UNCERTAINTY IN BOTH THE TRACK AND INTENSITY FORECAST
AFTER TAU 72, WITH SOME POTENTIAL FOR A STRONGER THAN EXPECTED
SYSTEM, WHICH LEADS TO A MORE WEST-NORTHWESTWARD TRACK INTO SOUTHERN
CHINA.  

MODEL DISCUSSION: THE 100000Z ECMWF ENSEMBLE (EPS) REVEALS A TIGHT
GROUPING OF SOLUTIONS THROUGH TAU 72, WITH INCREASING UNCERTAINTY
AFTER TAU 72. THE 100000Z GFS ENSEMBLE (GEFS) IS ALSO IN TIGHT
AGREEMENT THROUGH TAU 72. AFTER TAU 72, BOTH ENSEMBLES DIVERGE WITH
SOLUTIONS SPREAD FROM SOUTH OF HAINAN ISLAND TO HONG KONG. THIS
PRONOUNCED UNCERTAINTY AFTER TAU 72 IS ASSOCIATED WITH A WEAKENING
STR OVER THE HONG KONG, HAINAN ISLAND REGION DUE TO ENCROACHING
WESTERLIES OVER SOUTHEAST CHINA. A STRONG SYSTEM WOULD BE MORE
LIKELY TO TRACK WEST-NORTHWESTWARD WHILE A WEAKER SYSTEM WILL TURN 
WESTWARD TO SOUTHWESTWARD UNDER THE LOW-LEVEL STEERING FLOW. WITH THE 
EXCEPTION OF NAVGEM, WHICH SHARPLY RECURVES THE SYSTEM POLEWARD 
TOWARD TAIWAN, THE DETERMINISTIC GUIDANCE SHOWS A SIMILAR SPREAD OF 
SOLUTIONS AFTER TAU 72.         

FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: LOW
   INTENSITY 0 - 72 HR: HIGH
   INTENSITY 72-120 HR: LOW//
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