WDPN32 PGTW 110300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 10W (HALONG) WARNING 
NR 17//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 110000Z2 TO 140000Z5 JUL 02.
   A. TYPHOON (TY) 10W (HALONG), LOCATED APPROXIMATELY 700 NM 
SOUTH OF IWO JIMA, HAS TRACKED NORTHWESTWARD AT 09 KNOTS DURING THE 
PAST SIX HOURS. THE WARNING POSITION IS BASED ON 102330Z9 ENHANCED 
INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON 
SATELLITE CURRENT INTENSITY ESTIMATES OF 90 KNOTS. ANIMATED WATER 
VAPOR IMAGERY INDICATES THAT THE CONVECTION IN THE NORTHWEST 
QUADRANT HAS DECREASED IN RESPONSE TO A DEEPENING SHORTWAVE TROUGH 
LOCATED NEAR 14.1N5 137.6E7.
   B. THE SUBTROPICAL RIDGE LOCATED NORTH OF THE SYSTEM IS EXPECTED 
TO REMAIN QUASI-STATIONARY OVER THE NEXT 48 HOURS AND THEN WEAKEN AS 
AN UPPER LEVEL TROUGH TRACKS EASTWARD OVER MONGOLIA. TY 10W IS 
EXPECTED TO TRACK WEST-NORTHWESTWARD OVER THE NEXT 24 HOURS AND THEN 
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE. 
THE AVAILABLE DYNAMIC AIDS CONSIST OF THE NCEP AVIATION (AVN), 
NOGAPS, GFDN, COAMPS, AND THE JAPANESE GLOBAL (JGSM) MODELS. ALL 
AIDS ARE IN GOOD AGREEMENT WITH THIS SCENARIO, BUT HAVE BEEN 
CONSISTENTLY BIASED POLEWARD OF THE STORM TRACK. BASED ON THIS BIAS, 
OUR FORECAST IS SLIGHTLY EQUATORWARD OF A BLEND OF ALL AVAILABLE 
DYNAMIC AIDS.
   C. TY 10W IS EXPECTED TO AT A NEAR CLIMATOLOGICAL RATE OVER THE 
NEXT 48 HOURS WHILE THE SYSTEM REMAINS SOUTH OF THE RIDGE AXIS WITH 
ENHANCED EQUATORWARD OUTFLOW INTO THE UPPER LEVEL RIDGE LOCATED OVER 
NEW GUINEA. AFTERWARDS, TY 10W WILL WEAKEN SLOWLY AS THE SYSTEM 
TRACKS INTO A LESS FAVORABLE UPPER LEVEL ENVIRONMENT.
   D. CURRENT WIND RADII ARE BASED ON A RECENT QUICKSCAT PASS AND 
SYNOPTIC DATA. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN 
AVERAGE-SIZED SYSTEM. 
3. FORECAST TEAM: WINGEART/PIVIN/LAM/KUMAGA/STATEN//
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