MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (CHAMPI) WARNING NR 43// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 25W (CHAMPI), LOCATED APPROXIMATELY 444 NM EAST- NORTHEAST OF IWO TO, HAS TRACKED NORTHEASTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS AN ELONGATED AND RAGGED EYE FEATURE WITH CONTINUED DETERIORATION OF THE CONVECTIVE STRUCTURE, SPECIFICALLY ON THE WESTERN SIDE, AS IT BECOMES FURTHER ELONGATED TO THE NORTHEAST. A 231605Z AMSU-B IMAGE SHOWS ALL CONVECTION SHEARED TO THE NORTHEAST WITH AN ELONGATED LLCC. THE OVERALL SIGNATURE OF THE SYSTEM INDICATES THAT IT IS CURRENTLY GOING ETT. UPPER LEVEL ANALYSIS INDICATES A POOR ENVIRONMENT WITH VERTICAL WIND SHEAR IN EXCESS OF 30 KNOTS WITH NEAR DUAL CHANNEL OUTFLOW, WITH THE POLEWARD OUTFLOW ENHANCED BY THE MID- LATITUDE ZONAL FLOW. TY 25W IS TRACKING ALONG THE POLEWARD SIDE OF THE STR TO THE SOUTHEAST. 3. FORECAST REASONING. A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 25W WILL TRACK NORTHEASTWARD ALONG THE NORTHERN PERIPHERY OF THE STR THROUGHOUT THE FORECAST PERIOD. INCREASING VWS AND DECREASING SSTS WILL CONTINUE TO ERODE THE TYPHOON AS IT GAINS LATITUDE. TY CHAMPI WILL CONTINUE ETT AS IT EMBEDS IN THE BAROCLINIC ZONE AND WILL COMPLETE ETT BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE REMAINS IN VERY TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN