WDPN31 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 26W (BOPHA) WARNING NR 30//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 26W (BOPHA) LOCATED APPROXIMATELY 185 NM WEST OF 
PALAU, HAS TRACKED WESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. 
ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS TY 26W REMAINS WELL 
ORGANIZED WITH A VERY SYMMETRIC, COMPACT STRUCTURE. A NOTABLE DEEP 
BAND OF CONVECTION IS EVIDENT WRAPPING AROUND THE ENTIRETY OF THE 
SYSTEM, WITH A PAIR OF SECONDARY LESS CONVECTIVE BANDS ON THE EAST 
AND WEST SIDES OF THE PRIMARY BAND. A RECENT 022117Z SSMIS MICROWAVE 
PASS SUPPORTS THE WELL ORGANIZED STRUCTURE OF TY 26W AND SUGGESTS 
THE EYE IS ATTEMPTING TO RE-DEVELOP. THE CURRENT INTENSITY IS BASED 
ON A 5.5/5.5 DVORAK ESTIMATE FROM PGTW INDICATING 102 KNOTS. UPPER 
LEVEL ANALYSIS INDICATES THE POINT-SOURCE ANTICYCLONE REMAINS WELL 
ESTABLISHED AND CONTINUES TO PROVIDE AMPLE RADIAL OUTFLOW AND LOW 
(05 TO 10 KNOTS) VERTICAL WIND SHEAR (VWS) OVER THE SYSTEM. TY 26W 
CONTINUES TO TRACK WESTWARD ALONG THE SOUTHERN EXTENT OF THE DEEP-
LAYERED SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TY 26W IS FORECAST TO TRACK ON A STEADY WESTWARD TRACK ALONG 
THE SOUTHERN PERIPHERY OF THE STR, MAKING LANDFALL INTO THE 
PHILIPPINE ISLANDS AROUND TAU 24. THE FAVORABLE ENVIRONMENT OF LOW 
VWS, AMPLE OUTFLOW, AND HIGH OCEAN HEAT CONTENT WILL ALLOW THE 
SYSTEM TO MAINTAIN ITSELF AS A STRONG TYPHOON THROUGH LANDFALL, WITH 
ONLY A SLOW WEAKENING OF THE SYSTEM EXPECTED DUE TO A SLIGHT 
DECREASE IN ENVIRONMENTAL CONDITIONS. AFTER LANDFALL, TY 26W IS 
EXPECTED TO WEAKEN MORE QUICKLY AS THE SYSTEM TRACKS OVER THE 
PHILIPPINES.
   C. IN THE EXTENDED TAUS, TY 26W IS EXPECTED TO MOVE INTO THE 
SOUTH CHINA SEA (SCS), SLOWING AS THE SYSTEM MOVES INTO A COL REGION 
BETWEEN TWO ELONGATED LOBES OF THE STR. INCREASING VWS AND THE 
INTERACTION WITH A DEVELOPING NORTHEASTERLY COLD SURGE WILL HAMPER 
THE REORGANIZATION OF TY 26W AS IT TRACKS SLOWLY INTO THE CENTRAL 
SCS. THERE ARE SOME CONCERNS REGARDING THE INTENSITY AT LATER TAUS 
DUE TO THE SYSTEM MOVING OVER THE PHILIPPINES AND WHETHER THE 
POSSIBILITY FOR GREATER WEAKENING EXISTS THAN CURRENTLY SUGGESTED BY 
MODEL GUIDANCE. MODEL GUIDANCE REMAINS IN VERY GOOD AGREEMENT 
REGARDING THE TRACK THROUGHOUT THE FORECAST PERIOD, WITH ONLY A 
SLIGHT VARIATION BY TAU 120. DUE TO THIS TIGHT AGREEMENT, THE 
CONFIDENCE IN THE FORECAST TRACK REMAINS HIGH.//
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