WDPN32 PGTW 201500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 13W WARNING 
NR 09//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 201200Z3 TO 231200Z7 JUL 02.
   A. TROPICAL STORM (TS) 13W, APPROXIMATELY 66 NM SOUTH OF 
MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 06 KNOTS 
DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 201130Z7 
ENHANCED INFRARED SATELLITE IMAGERY AND SYNOPTIC REPORTS IN THE 
PHILIPPINE ISLANDS. THE WARNING INTENSITY IS BASED ON SATELLITE 
CURRENT INTENSITY ESTIMATES OF 35 KNOTS AND SYNOPTIC REPORTS. 
   B. A LOW LEVEL CIRCULATION LOCATED APPROXIMATELY 24.0N6 142.0E7 
IS EXPECTED TO INTENSIFY AND TRACK WEST-NORTHWESTWARD AND INTERACT 
WITH TS 13W BY THE END OF THE FORECAST PERIOD. TS 13W IS FORECAST TO 
TRACK WEST-NORTHWESTWARD THROUGH 12 HOURS AND THEN NORTH-
NORTHWESTWARD AS THE SYSTEM BEGINS TO INTERACT WITH THE LOW LEVEL 
CIRCULATION TO THE NORTHEAST. THE AVAILABLE DYNAMIC AIDS CONSISTING 
OF NOGAPS, GFDN, COAMPS, AFWA MM5, UKMET GLOBAL (EGRR), NCEP 
AVIATION (AVN), AND THE JAPANESE GLOBAL (JGSM) MODELS ARE IN POOR 
AGREEMENT. WITH THE EXCEPTION OF JGSM, ALL THE AIDS KEEP TS 13W WEAK 
AND GENERALLY INDICATE THAT THE SYSTEM WILL RECURVE SHARPLY AND 
TRACK OVER THE PHILIPPINE SEA BUT VARY SPEED AND TIME OF 
RECURVATURE. OTHER THAN AVN, THESE AIDS HAVE CONSISTENTLY HAD A 
WESTWARD BIAS. GFDN, COAMPS, MM5, AND EGRR DISSIPATE THE SYSTEM 
WITHIN 48 HOURS, WHILE NOGAPS, JGSM, AND AVN CONTINUE TO TRACK THE 
SYSTEM THROUGH 72 HOURS. ALL AIDS INDICATE SOME INTERACTION WITH THE 
LOW LEVEL CIRCULATION. OUR FORECAST IS BASED ON PERSISTENCE AND THE 
AVN MODEL.
   C. TD 13W IS NOT EXPECTED TO INTENSIFY SIGNIFICANTLY OVER THE 
NEXT 24 HOURS WHILE INTERACTING WITH THE CENTRAL PHILIPPINE ISLANDS. 
AFTERWARDS, TD 13W IS EXPECTED TO SLOWLY INTENSIFY AS IT TRACKS OVER 
THE EAST CHINA SEA.
   D. FORECAST WIND RADII IS BASED ON CLIMATOLOGY FOR AN AVERAGE-
SIZED SYSTEM. 
3. FORECAST TEAM: WINGEART/LAM/KUMAGA/STATEN