WDPN31 PGTW 251500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL//JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (KONG-REY) WARNING NR 18// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 251200Z0 TO 281200Z3 JUL 01. A. TYPHOON (TY) 09W (KONG-REY), LOCATED APPROXIMATELY 450 NM SOUTH OF TOKYO, JAPAN, HAS TRACKED NORTHWARD AT 06 KNOTS OVER THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 251130Z2 INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON CURRENT INTENSITY ESTIMATES OF 77 AND 90 KNOTS. ANIMATED INFRARED SATELLITE IMAGERY DEPICTS A 26 NM IRREGULAR EYE. A 250825Z2 SPECIAL SENSOR MICROWAVE IMAGER PASS DEPICTS TIGHTLY-WRAPPED CONVECTIVE BANDING SOUTH OF THE SYSTEM CENTER. ANIMATED WATER VAPOR IMAGERY SHOWS VERY GOOD OUTFLOW ENHANCED BETWEEN THE MID-LATITUDE WESTERLIES NORTH OF THE SYSTEM AND A TROPICAL UPPER LOW CENTERED SOUTHEAST OF TY 09W, NEAR 21N3 151E7. B. THE MID-LEVEL RIDGE EAST OF TY 09W REMAINS THE DOMINANT STEERING MECHANISM. THIS PERIPHERAL RIDGE HAS STRENGTHENED JUST EAST OF TY 09W, WHILE THE HIGH CENTER NEAR 34N7 154E0 HAS ELONGATED AND WEAKENED IN RESPONSE TO A WEAK MID-LATITUDE TROUGH DIGGING EAST OF NORTHERN HONSHU. THE DYNAMIC AIDS ARE IN INCREASINGLY POOR AGREEMENT WITH TWO POSSIBLE ERROR MECHANISMS CLEARLY INDICATED IN THE FIELDS. THE JMA GLOBAL SPECTRAL MODEL (JGSM) AND TYPHOON MODEL (JTYM) INITIALIZE THE SYSTEM CENTER ABOUT 60 NM WEST OF THE ACTUAL POSITION. ADDITIONALLY, THE JTYM TRACK HAS REMAINED ERRATIC AND TRACKS THE SYSTEM NORTHWARD THROUGH THE FORECAST PERIOD. THE GEOPHYSICAL FLUID DYNAMIC-NAVY MODEL INDICATES ERRONEOUS INTERACTION AND MERGER WITH THE MID-LATITUDE TROUGH AFTER 24 HOURS, RESULTING IN A FASTER SPEED OF ADVANCE AND A MORE EAST-NORTHEASTWARD TRACK. THE NOGAPS MODEL INDICATES ERRONEOUS INTERACTION WITH THE LOW CENTER NEAR 14N5 134E8, RESULTING IN A CYCLONICALLY-CURVED TRACK AFTER 48 HOURS. THE OFFICIAL FORECAST FAVORS THE DYNAMIC AID CONSENSUS, AND INDICATES A MORE NORTHWARD TRACK THROUGH 24 HOURS DUE TO THE DEVELOPING PERIPHERAL RIDGE, THEN A GRADUAL TURN NORTHEASTWARD. THIS TRACK CORRESPONDS WELL WITH THE JGSM MODEL, WHICH DOES NOT HAVE ANY INDICATIONS OF APPARENT ERROR MECHANISMS IN THE FIELDS. DUE TO THE POOR AGREEMENT IN DYNAMIC AIDS, THERE IS SOME UNCERTAINTY IN THE FORECAST TRACK AFTER 48 HOURS. C. TY 09W IS EXPECTED TO MAINTAIN INTENSITY OVER THE NEXT 24 HOURS, THEN IS EXPECTED TO WEAKEN UNDER MODERATE WESTERLY FLOW UNTIL EXTRA-TROPICAL TRANSITION IS COMPLETED NEAR THE 72 HOUR POINT. D. THE WIND RADII ARE BASED ON RECENT MICROWAVE DATA, AND HAVE BEEN ADJUSTED AFTER 36 HOURS TO ACCOUNT FOR INCREASING GRADIENT WINDS IN THE NORTHERN SEMI-CIRCLE. FORECAST TEAM: BARLOW/VILPORS/WAUGAMAN/SHERRY// NNNN