WDPN31 PGTW 040300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 14W WARNING NR 24//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 040000Z TO 090000Z SEP 2005.
   A. TYPHOON (TY) 14W (NABI), LOCATED APPROXIMATELY 240 NM EAST-
SOUTHEAST OF OKINAWA, HAS TRACKED NORTH-NORTHWESTWARD AT 10 KNOTS
OVER THE PAST SIX HOURS.
   B.  TY 14W IS TRACKING NORTH-NORTHWESTWARD ALONG THE SOUTHWESTERN
PERIPHERY OF A MID-LEVEL STEERING RIDGE LOCATED EAST-SOUTHEAST OF
JAPAN. A PERIPHERAL MID-LEVEL ANTICYCLONE TO THE SOUTHEAST OF TY 14W
IS PROVIDING AN ADDITIONAL POLEWARD STEERING COMPONENT. THIS MOTION
IS FORECAST TO CONTINUE THROUGH TAU 36. CURRENTLY THE JET STREAM IS
ORIENTED SOUTHWEST TO NORTHEAST, EXTENDING FROM EASTERN ASIA TO 
NORTHERN JAPAN KEEPING THE STEERING RIDGE FROM BUILDING WESTWARD
AND POLEWARD. THIS PATTERN HAS CAUSED TY 14W TO TRACK MORE NORTH-
NORTHWESTARD THAN THE MODELS ARE DEPICTING AS THE MAJORITY OF THE
MODELS MAINTAIN A NORTHWESTWARD TRACK TOWARDS THE KOREAN PENNISULA.
THE MODELS ARE NOT IN GOOD AGREEMENT AND BASED ON THE SYNOPTIC
PATTERN, THE FORECAST IS WEIGHTED TOWARD THE EASTERN MOST MEMBERS
OF THE CONSENSUS (COAMPS, MM5, TCLI, JGSM, AND JTYM). THE WESTERN
MEMBERS OF THE CONSENSUS (NOGAPS, WBAI, EGRR, GFDN, AND GFS)
EXCESSIVELY DEEPEN AN EAST ASIAN TROUGH AND BUILD AN UPPER RIDGE
NORTH OF TY 14W, WHICH WOULD FAVOR A DELAYED RECURVATURE SCENARIO.
   C. TY 14W IS FORECAST TO INTENSIFY OVER THE NEXT 24 TO 48 HOURS
AS IT REMAINS IN A LOW VERTICAL WIND SHEAR ENVIRONMENT, TRAVERSES
MORE FAVORABLE SEA SURFACE TEMPERATURES (SST), AND DEVELOPS A
POLEWARD OUTFLOW CHANNEL WHILE APPROACHING THE BAROCLINIC ZONE OVER
JAPAN. WEAKENING WILL BEGIN AFTER 48 HOURS AS THE STORM INTERACTS
WITH LAND AND ENCOUNTERS LOWER SST.      
   D. CURRENT WIND RADII ARE BASED ON 032100Z SYNOPTIC OBSERVATIONS
AND A 032038Z QUIKSCAT PASS. FORECAST WIND RADII ARE BASED ON CLIM-
ATOLOGY FOR A LARGE SIZED SYSTEM.
   E. THERE IS LOW CONFIDENCE IN THE FORECAST TRACK AFTER TAU 72 AS
THE MODELS ARE IN DISAGREEMENT. NOGAPS, GFDN AND AVN MODELS TRACK
THE SYSTEM NORTHWARD THROUGH THE WESTERLIES INTO EASTERN RUSSIA. THE
FORECAST DEPICTS A RECURVATURE SCENARIO TO OCCUR SOONER AND MUCH
SHARPER THAN EARLIER FORECASTS WITH THE FORECAST TRACKING THROUGH
THE SEA OF JAPAN TOWARDS NORTHERN JAPAN. THIS IS IN RESPONSE TO
THE PERSISTENT WESTERLIES ALOFT SITUATED OVER EAST ASIA, KOREA, AND
JAPAN. GIVEN THE FORECAST MOTION, THE STORM WILL BEGIN TO INTERACT
WITH AND EVENTUALLY BECOME EMBEDDED IN THE MIDLATITUDE WESTERLIES
BETWEEN 96 AND 120 HOURS. THE SYSTEM WILL CONTINUE TO WEAKEN AS IT
UNDERGOES EXTRATROPICAL (XT) TRANSITION AND ENCOUNTERS LOW SST. THE
STORM WILL BE FULLY XT BY TAU 120.    
3. FORECAST TEAM: DELTA//