WDPN31 PGTW 021500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 16W WARNING NR/ 
02//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 021200Z5 TO 051200Z8 AUG 02.
   A. TROPICAL DEPRESSION (TD) 16W, LOCATED OVER THE SOUTH CHINA 
SEA, HAS TRACKED WEST-NORTHWEST AT 07 KNOTS OVER THE PAST 6 HOURS. 
THE WARNING POSITION IS BASED ON 021130Z7 ENHANCED INFRARED 
SATELLITE IMAGERY AND SURFACE OBSERVATIONS. THE WARNING INTENSITY IS 
BASED ON SHIP REPORTS OF 30 KNOTS. A 021027Z2 SSM/I PASS DEPICTED 
DEEP CONVECTION SURROUNDING THE VORTEX. A BANDING FEATURE EXTENDING 
OVER THE SOUTH QUADRANT IS ALSO VISIBLE. 
   B. A MID LEVEL RIDGE EXTENDING OVER THE EAST CHINA SEA IS 
FORECAST TO WEAKEN WITH AN APPROACH OF A BAROCLINIC LOW AND 
ASSOCIATED TROUGH FROM NORTHEAST CHINA. THIS SHOULD CAUSE TD 16W TO 
TURN INCREASINGLY TO THE NORTHWEST. AVAILABLE DYNAMICAL MODELS 
(NOGAPS, AVN, GFDN, JMA GLOBAL, AND UKMETO) ALL INDICATE POOR 
INITIALIZATION OF THE SYSTEM. FOR EXAMPLE, THE AVN CONTINUES TO 
DEVELOP AND TRACK THE POOR AREA (91W) SOUTHEAST OF TAIWAN RATHER 
THAN THE TROPICAL DEPRESSION. ALL MODELS, HOWEVER, ARE IN AGREEMENT 
WITH THE MID LEVEL RIDGE WEAKENING THROUGH THE PERIOD. BUT, BASED ON 
THE 36 HOUR MODEL RUN TREND AND THE TROPICAL DEPRESSION'S CURRENT 
MOTION, THE CONSENSUS HAS BEEN PREMATURE ON THE NORTHWARD TURN. OUR 
FORECAST IS BASED ON PERSISTENCE, THE MID LEVEL BETA ADVECTION 
MODELS BASED OFF OF THE NOGAPS RUN, AND A BLEND OF NOGAPS, THE 
UKMETO GLOBAL, AND THE JMA GLOBAL.  
   C. AN UPPER LEVEL LOW SITUATED TO THE NORTHWEST OF THE TD OVER 
EASTERN CHINA IS EXPECTED TO ENHANCE THE OUTFLOW ABOVE THE TD OVER 
THE NEXT 6 HOURS. AFTERWARD, NWP AGREES WITH A RAPID FILL AND 
RETROGRADE MOVEMENT. THROUGH THE REMAINDER OF THE PERIOD, LIGHT TO 
MODERATE UPPER NORTHEASTERLIES ARE FORECAST TO ESTABLISH OVER THE 
AREA AS AN UPPER HIGH BEGINS TO BUILD IN FROM CENTRAL CHINA. THIS 
SHOULD INFLUENCE A STEADY TO SLOW DEVELOPMENT RATE.   
   D. THE WIND RADII FORECAST IS BASED ON CLIMATOLOGY FOR AN AVERAGE 
SIZE TROPICAL CYCLONE.
3. FORECAST TEAM: ROBERTS/WARREN/RONSSE/EDBERG/SCHAEFER//