WDPN31 PGTW 060300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (KROSA) WARNING NR 
10//
RMKS/
1. FOR METEOROLOGISTS.
2. PROGNOSTIC REASONING FOR 060000Z6 TO 090000Z9 OCT 01.
   A. TYPHOON (TY) 24W (KROSA), LOCATED APPROXIMATELY 355 NM 
WEST-SOUTHWEST OF IWO JIMA, HAS TRACKED NORTHWESTWARD AT 09 KNOTS 
DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 052330Z3
VISIBLE AND INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS 
BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 90 TO 102 KNOTS. 
ANIMATED SATELLITE IMAGERY INDICATES THAT THE SYSTEM HAS WEAKENED 
SLIGHTLY, LOSING ITS EYE OVER THE PAST 6 HOURS. A RECENT SPECIAL 
SENSOR MICROWAVE IMAGER (SSMI) PASS DEPICTS WEAKENING OF THE DEEP 
CONVECTION. ANIMATED WATER VAPOR IMAGERY SHOWS GOOD OUTFLOW POLEWARD 
OF THE CENTER.
   B. TY 24W IS FORECAST TO TRACK GENERALLY NORTHWARD UNDER THE 
STEERING INFLUENCE OF THE MID-LEVEL SUBTROPICAL RIDGE LOCATED TO THE 
NORTHEAST THROUGH 36 HOURS. AFTER THAT, THE SYSTEM SHOULD BEGIN TO 
TRACK MORE NORTHEASTWARD AS IT INTERACTS WITH THE MID-LATITUDE 
WESTERLIES NORTH OF THE SUBTROPICAL RIDGE. THE AVAILABLE DYNAMIC 
AIDS OF NOGAPS (NGPS), AVIATION (AVN), JMA TYPHOON (JTYM), 
GEOPHYSICAL FLUID DYNAMICS-NAVY (GFDN), AND THE UKMET-OFFICE GLOBAL 
(EGRR) MODELS ARE IN GOOD AGREEMENT ON TRACK. HOWEVER, THE GUIDANCE 
VARIES IN SPEED WITH JGSM TRACKING THE SYSTEM VERY SLOWLY NORTH, AND 
THE OTHER MODELS INDICATING FASTER ACCELERATION TO THE NORTHEAST. 
JTWC ATTRIBUTES THE SLOW TRACK OF JGSM TO EXCESSIVE INTERACTION WITH 
A MONSOON TROUGH EXTENDING SOUTHWESTWARD OVER THE SOUTH CHINA SEA. 
THE NUMERICAL CONSENSUS CONSISTS OF FIVE MODELS (NGPS, GFDN, JGSM, 
JTYM, AND EGRR). THE OFFICIAL FORECAST IS BASED ON THE SELECTED 
CONSENSUS THAT EXCLUDES JGSM.
   C. TY 24W IS EXPECTED TO SLOWLY WEAKEN AS IT TRACKS INTO 
INCREASING SHEAR AND STRONGER MID-LATITUDE WESTERLIES. 
   D. WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZE 
SYSTEM.
FORECAST TEAM: COX/LEEJOICE/WAUGAMAN/SHERRY//