WDPN32 PGTW 031500 
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W WARNING 
NR 10//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 031200Z6 TO 061200Z9 JUL 01.
   A. TYPHOON (TY) 06W (UTOR), LOCATED APPROXIMATELY 370 NM 
EAST-SOUTHEAST OF PORT SAN VICENTE, LUZON, HAS TRACKED NORTHWESTWARD 
AT 20 KNOTS OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 
031130Z8 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY 
IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 65 KNOTS. 
INFRARED ANIMATION AND A 031138Z6 SPECIAL SENSOR MICROWAVE IMAGER 
(85 GHZ) PASS DEPICT AN INTENSE BANDING FEATURE CONFINED TO THE 
SOUTH SEMI-CIRCLE. APPARENTLY, THE UPPER EASTERLIES ASSOCIATED WITH 
THE UPPER ANTICYCLONE LOCATED EAST OF TAIWAN ARE HAMPERING DEEP 
BANDING DEVELOPMENT OVER THE NORTH SEMI-CIRCLE.
   B. MID-LEVEL HIGH HEIGHT CENTER SITUATED OVER SOUTHERN JAPAN, 
WITH ASSOCIATED RIDGE EXTENDING OVER THE COAST OF CHINA, IS FORECAST 
TO WEAKEN WITH AN APPROACH OF SHORT WAVE TROUGH NEAR THE 36 HOUR 
PERIOD. THEREFORE, TY 06W SHOULD SHOW A SLIGHT STAIR STEP WITHIN THE 
WEAKNESS NEAR TAIWAN BEFORE CONTINUING ON A GENERALLY WEST-
NORTHWESTWARD TRACK TOWARD THE CHINA COAST. THE DYNAMIC MODELS ALL 
AGREE WITH THIS SCENARIO WITH SLIGHT VARIATIONS. NOGAPS, UKMET, THE 
JMA TYPHOON, THE AFWA MESOSCALE (MM5), THE KOREA MET GLOBAL, AND THE 
MRF AVN RUN REVEAL A MORE PRONOUNCED NORTHWESTWARD STAIR STEP. 
BEYOND 48 TAU, THE GEOPHYSICAL FLUID DYNAMICS (NAVY) REGIONAL AND 
THE JMA TYPHOON AND GLOBAL MODELS SHOW A MORE WESTWARD TRACK. THIS 
IS CAUSED BY A COMBINATION OF EXCESSIVE INTERACTION WITH THE MONSOON 
TROUGH OVER THE SOUTH CHINA SEA AND A STRONGER MID-LEVEL RIDGE 
BUILDING IN BEHIND THE SHORT WAVE TROUGH. THE OFFICAL FORECAST IS 
BASED ON PERSISTENCE AND THE FIRST MODEL CLUSTER THAT INDICATES A 
STAIR STEP WITHIN THE WEAKNESS THEN A TRACK INTO CHINA INFLUENCED 
BY AN APPROACHING MID-LAT RIDGE FROM THE NORTHWEST. 
   C. TY 06W SHOULD CONTINUE ON A RAPID INTENSIFICATION SCENARIO 
DURING THE NEXT 12 TO 18 HOURS BASED ON THE POSITION OF THE TUTT TO 
THE NORTHWEST, ANTICYCLONIC OUTFLOW OVER THE LLCC, SEA SURFACE TEMPS 
GREATER THAN 26 CELSIUS, AND, THE PRESENCE OF AN EQUATORWARD OUTFLOW 
CHANNEL. THE DISSIPATION OF THE TUTT, THE INFLUENCE OF STRONGER 
UPPER EASTERLIES ASSOCIATED WITH AN UPPER HIGH SITUATED EAST OF 
TAIWAN, AND THE ABSENCE OF PRONOUNCED CROSS EQUATORIAL OUTFLOW 
SHOULD PROVIDE FOR A MORE CLIMATOLOGICAL TREND BY MID PERIOD.    
   D. THE WIND RADII ARE BASED ON SYNOPTIC DATA, MICROWAVE IMAGERY 
AND CLIMATOLOGY FOR A LARGE-SIZED TROPICAL CYCLONE.
FORECAST TEAM: ROBERTS/BALDINGER/HARRISON/CUTMAN//



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