WDPN31 PGTW 300300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 30W
/WARNING NR 06//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 300000Z3 NOV TO 050000Z5 DEC 2004.
   A. TYPHOON (TY) 30W (NANMADOL), LOCATED APPROXIMATELY 180 NM
EAST-SOUTHEAST OF YAP, HAS TRACKED WEST-NORTHWESTWARD AT 20 KNOTS
OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 292330Z9 
MULTISPECTRAL SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON
SATELLITE CURRENT INTENSITY ESTIMATES OF 55, 65, AND 77 KNOTS. 
   B. TY 30W IS FORECAST TO CONTINUE TO TRACK WEST-NORTHWEST ALONG
THE SOUTHWEST PERIPHERY OF THE SUBTROPICAL RIDGE CENTERED TO THE
NORTHEAST. A SHORTWAVE TROUGH APPROACHING CHINA WILL BEGIN TO
WEAKEN THE RIDGE AT APPROXIMATELY TAU 72 AS TY 30W MAKES LANDFALL
ALONG THE EAST COAST OF THE PHILIPPINES. THE AVAILABLE DYNAMIC AIDS
CONSISTING OF WBAR, COAMPS, JGSM, JTYM, GFDN, NOGAPS, NCEP GFS, TCLAPS
AND UKMI ARE IN VERY GOOD AGREEMENT. THIS FORECAST IS BASED ON A
CONSENSUS OF ALL AVAILABLE DYNAMIC AIDS WITH LESS EMPHASIS ON JGSM
AND WBAR.
   C. THE INTENSITY OF TY 30W IS EXPECTED TO INCREASE AT A
CLIMATOLOGICAL RATE. THE SYSTEM HAS STRONG RADIAL OUTFLOW WHICH IS
EXPECTED TO OFFSET MODERATE VERTICAL WIND SHEAR THAT THE SYSTEM WILL 
ENCOUNTER OVER THE NEXT 24-36 HOURS.
   D. CURRENT WIND RADII ARE BASED ON A 292030Z6 QUICKSCAT PASS.
FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR A LARGE SIZED SYSTEM.
   E. THE SHORTWAVE TROUGH TRACKING OVER CHINA WILL PROVIDE A WEAKNESS
IN THE STEERING RIDGE TO THE NORTH BEYOND TAU 72 ALLOWING TY 30W TO TURN
POLEWARD. TY 30W WILL WEAKEN IN INTENSITY DURING THE EXTENDED FORECAST
PERIOD AS IT INTERACTS WITH THE TERRAIN OF THE PHILIPPINES AND ENCOUNTERS
INCREASED VERTICAL WIND SHEAR CHARACTERISTIC OF THE NORTHEAST MONSOON.
3. FORECAST TEAM: DIXON/FJELD/SCHULTZ/SPANSKI//