WDPN33 PGTW 291500 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W WARNING NR 09// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 291200Z4 AUG TO 031200Z6 SEP 2004. A. TYPHOON (TY) 22W (SONGDA), LOCATED APPROXIMATELY 665 NM EAST OF SAIPAN, HAS TRACKED WEST-NORTHWESTWARD AT 15 KNOTS OVER THE PAST 06 HOURS. THE WARNING POSITION IS BASED ON 291130Z6 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 55 AND 65 KNOTS. B. TY 22W IS FORECAST TO CONTINUE TRACKING WEST-NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF THE LOW TO MID-LEVEL STEERING RIDGE LOCATED NORTH OF THE SYSTEM. THE AVAILABLE DYNAMIC AIDS CONSISTING OF NGPS, GFDN, WBAR, JGSM, JTYM, COAMPS, AFWA MM5, NCEP GFS AND UKMET EGRR ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS FORECAST IS BASED ON A BLEND OF ALL THE AVAILABLE DYNAMIC AIDS. C. TY 22W IS EXPECTED TO INTENSIFY AT A NEAR CLIMATOLOGICAL RATE IN A FAVORABLE ENVIRONMENT OF WEAK VERTICAL WIND SHEAR AND GOOD DIFFLUENCE ALOFT. D. CURRENT AND FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZED SYSTEM. E. THE EXTENDED GUIDANCE INDICATES THAT TY 22W WILL TRACK SLIGHTLY MORE WESTWARD AS THE STEERING RIDGE STRENGTHENS AND BUILDS TO THE WEST. TY 22W IS FORECAST TO WEAKEN SLIGHTLY IN THE LATER TAUS AS IT TRACKS UNDER THE SOUTHEAST QUADRANT OF THE UPPER LEVEL RIDGE AND EXPERIENCES LESS FAVORABLE OUTFLOW CON- DITIONS AND INCREASED EASTERLY SHEAR. 3. FORECAST TEAM: KENDALL/FJELD/VOHS// NNNN