WDPN31 PGTW 170300 
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 31W (FAXAI) WARNING NR 
22//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 170000Z8 TO 200000Z2 DEC 01.
   A. TROPICAL STORM (TS) 31W (FAXAI), LOCATED APPROXIMATELY 80 NM 
WEST-NORTHWEST OF THE ISLAND OF KOSRAE, HAS REMAINED QUASI-
STATIONARY OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 
162330Z5 INFRARED AND VISIBLE SATELLITE IMAGERY, RECENT MICROWAVE 
SATELLITE IMAGERY, AND SYNOPTIC DATA. THE WARNING INTENSITY IS BASED 
ON SATELLITE CURRENT INTENSITY ESTIMATES OF 35 AND 45 KNOTS. 
ANIMATED INFRARED AND VISIBLE SATELLITE IMAGERY INDICATES CYCLING 
CONVECTION OVER THE LOW LEVEL CIRCULATION CENTER (LLCC). 
   B. TS 31W REMAINS EMBEDDED IN A WEAK STEERING ENVIRONMENT WITHIN 
THE HORIZONTAL SHEAR OF THE SUBTROPICAL NORTHEASTERLIES AND 
EQUATORIAL WESTERLIES. THE SYSTEM IS EXPECTED TO REMAIN IN THIS 
ENVIRONMENT, THEREFORE IT SHOULD CONTINUE TO TRACK IN A GENERAL 
WEST-NORTHWESTWARD DIRECTION WITH SHORT TERM FLUCTUATIONS. THE 
AVAILABLE MODELS OF AVN, GFDN, NOGAPS, JGSM, AND THE UKMET (EGRR) 
ARE IN FAIR AGREEMENT, TRACKING THE SYSTEM WEST-NORTHWESTWARD. THE 
MODELS VARY SLIGHTLY IN SPEED OF MOTION. GFDN AND NGPS TRACK THE 
SYSTEM QUICKER THAN THE REMAINING MODELS. OUR FORECAST IS BASED ON 
PERSISTENCE, AND A BLEND OF THE AFOREMENTIONED MODELS, WITH A SLOWER 
SPEED OF ADVANCE.
   C. 200 MB ANALYSIS INDICATES THE REGION IS IN A WEAK TO MODERATE 
VERTICAL WIND SHEAR ENVIRONMENT WITH FAIR OUTFLOW ALOFT. CONDITIONS 
SHOULD IMPROVE LATER IN THE PERIOD, THEREFORE, THE SYSTEM IS 
EXPECTED TO SLOWLY INTENSIFY.  
   D. WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGED SIZE 
SYSTEM. 
FORECAST TEAM: MAZANY/JACOBS/LAM/SHERRY/KUMAGA//