WDPN33 PGTW 200300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (FRANCISCO) WARNING 
NR 5//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 200000Z2 TO 230000Z5 SEP 01.
   A. TROPICAL STORM (TS) 22W, LOCATED APPROXIMATELY 880 NM EAST-
NORTHEAST OF GUAM HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS DURING 
THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 192330Z8 
INFRARED AND VISIBLE SATELLITE IMAGERY. THE WARNING INTENSITY IS 
BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 35 KNOTS. ALTHOUGH 
VISIBLE ANIMATION DEPICTS LITTLE IMPROVED ORGANIZATION OVER THE PAST 
6 HOURS, DEEP CONVECTION COVERAGE CONTINUES TO INCREASE.  
   B. TS 22W IS FORECAST TO TRACK WITHIN THE MID-LEVEL EASTERLY FLOW 
PATTERN ASSOCIATED WITH THE SUBTROPICAL HIGH SITUATED EAST OF JAPAN 
DURING THE NEXT 48 HOURS. AFTERWARD, A MAJOR SHORT WAVE TROUGH 
MOVING OVER JAPAN SHOULD BEGIN TO WEAKEN THE EASTERN EXTENT OF THE 
RIDGE CAUSING TS 22W TO TAKE A MORE NORTHWESTWARD TRACK. THE 
NUMERICAL MODELS (NOGAPS, AVN, GFDN, COAMPS, JMA GLOBAL AND 
TYPHOON,) ARE IN AGREEMENT WITH THE AFOREMENTIONED SCENARIO. THERE 
IS AN OUTLIER, (UKMET-O SPECTRAL) HOWEVER, WITH RESPECT TO SPEED OF 
MOTION (SOA). THE UKMET MODEL AGGRESSIVELY MERGES THE TC WITH A MID-
LEVEL LOW/TROUGH (POSSIBLE MONSOON TROUGH REFLECTION) WEST OF THE 
MARIANA ISLANDS. THIS ERRONEOUS INTERACTION CREATES A FASTER SOA 
COMPARED TO THE ABOVE MODEL CLUSTER. OUR FORECAST IS BASED ON 
PERSISTENCE AND A BLEND OF NOGAPS, AVN, GFDN, COAMPS, AND THE JMA 
GLOBAL AND TYPHOON RUN.
   C. A TROPICAL UPPER TROPOSPHERIC LOW SITUATED NORTH-NORTHEAST OF 
THE MARIANA ISLANDS, IS ENHANCING THE OUTFLOW OVER THE SYSTEM. THE 
UPPER LOW IS FORECAST TO RETROGRADE WHICH IN TURN SHOULD PROVIDE A 
DIFFLUENT WIND FIELD ALOFT THROUGH THE PERIOD. AS A RESULT, TS 22W 
SHOULD INTENSIFY OVER THE FORECAST. 
   D. WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE 
TROPICAL CYCLONE.
FORECAST TEAM: ROBERTS/BALDINGER/HARRISON//