MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 22W (PRAPIROON) WARNING NR 14// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 22W (PRAPIROON), LOCATED APPROXIMATELY 440 NM SOUTH- SOUTHEAST OF KADENA AIR BASE, OKINAWA, JAPAN, HAS TRACKED WEST- NORTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE IMAGERY AND A 101825Z AMSU-B MICROWAVE IMAGE DEPICT A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH TIGHTLY-CURVED BANDING. ANIMATED WATER VAPOR IMAGERY SHOWS RADIAL OUTFLOW CONTINUES TO BE ENHANCED BY STRONG WESTERLY FLOW TO THE NORTH. THE INITIAL INTENSITY IS BASED ON DVORAK INTENSITY ESTIMATES OF 90 KNOTS FROM PGTW, KNES, AND RJTD. THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED ON AN EYE FEATURE IN THE AMSU-B IMAGERY. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS BENEATH A POINT SOURCE ANTICYCLONE IN AN AREA OF LOW (05-10 KNOT) VERTICAL WIND SHEAR (VWS). THE CYCLONE IS TRACKING SLOWLY ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) SOUTH OF JAPAN. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 22W IS EXPECTED TO CONTINUE TRACKING SLOWLY WEST- NORTHWESTWARD THROUGH THE NEXT 12 HOURS. BETWEEN TAUS 12 AND 24 THE WESTERN EXTENT OF THE STR IS EXPECTED TO BREAK DOWN DUE TO A PASSING MID-LATITUDE TROUGH CURRENTLY JUST EAST OF THE KOREAN PENINSULA. THE NEAR EQUATORIAL RIDGE TO THE SOUTHEAST OF TY 22W IS THEN EXPECTED TO BUILD AND BRIEFLY RESULT IN A MORE NORTHERLY TRAJECTORY FOR 22W. AFTER TAU 24, TY 22W WILL THEN SLOWLY RECURVE AROUND THE WESTERN EXTENT OF THE WEAKENED STR TO THE EAST AND TAKE ON A NORTHEASTWARD TRACK THROUGH TAU 72. TY 22W HAS THE POTENTIAL TO INTENSIFY UP TO 110 KNOTS DUE TO LOW VWS, FAVORABLE SEA SURFACE TEMPERATURES, AND FAVORABLE OUTFLOW. DYNAMIC MODEL GUIDANCE IS IN GENERAL AGREEMENT ON THE RECURVATURE BUT REMAINS IN POOR AGREEMENT ON THE SPEED AND TIMING OF THE TURN. IN THE EARLY TAUS, THE JTWC TRACK FORECAST REMAINS EAST OF CONSENSUS TO OFFSET THE UNLIKELY FAR WESTERN JGSM SOLUTION. FROM TAU 36 THROUGH 72 THE FORECAST TRACK IS SLIGHTLY WEST OF CONSENSUS TO OFFSET GFDN, THE RIGHTMOST OUTLIER. C. AFTER TAU 72, TY PRAPIROON IS EXPECTED TO SLOWLY BEGIN ACCELERATING AS IT CONTINUES TO TRACK NORTHEASTWARD ALONG THE NORTHWESTERN PERIPHERY OF THE STR. DECREASING OCEAN HEAT CONTENT AND INCREASING VERTICAL WIND SHEAR WILL RESULT IN A GRADUAL REDUCTION IN INTENSITY. DYNAMIC MODEL GUIDANCE DIVERGES, WITH NOGAPS AND GFDN FAVORING A MUCH FASTER AND MORE EASTERLY TRACK AND JGSM, ECMWF, AND EGRR INDICATING A SLOWER AND MORE WESTERLY TRACK. THE JTWC FORECAST FAVORS THE CONSISTENT GFS SOLUTION AND IS SLOWER THAN THE MULTI- MODEL CONSENSUS TO OFFSET THE FASTEST MODELS.// NNNN NNNN