MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 17W (PEIPAH) WARNING NR 07// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 17W (PEIPAH), LOCATED APPROXIMATELY 152 NM EAST-SOUTHEAST OF IWO TO, HAS TRACKED NORTH-NORTHWESTWARD AT 28 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A DEGRADED LOW LEVEL CIRCULATION CENTER (LLCC) LOCATED TO THE NORTHEAST OF THE ASSOCIATED CONVECTION, WHICH IS BEING SHEARED TO THE SOUTHWEST, SUPPORTING HIGH CONFIDENCE IN THE INITIAL POSITION. A 152335Z METOP-C ASCAT PASS DEPICTS AN AREA OF 30-35 KT WINDS TO THE EAST OF THE LLCC. THE INITIAL INTENSITY OF 30 KTS IS BASED ON THE AFOREMENTIONED ASCAT PASS AND MULTI-AGENCY DVORAK ESTIMATES OF T1.5 (25 KTS). DESPITE STRONG EQUATORWARD OUTFLOW AND WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURE (SST), THE HIGH (40-50 KNOTS) VERTICAL WIND SHEAR AND WEAK DIVERGENCE ALOFT PLACE TD 17W IN AN INCREASINGLY HOSTILE ENVIRONMENT. TD 17W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A NORTH-SOUTH ORIENTED SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. FOR THE DURATION OF THE FORECAST, TD 17W WILL TRACK NORTH-NORTHWESTWARD ALONG THE PERIPHERY OF THE STR. DISSIPATION WILL OCCUR BETWEEN TAU 24 AND 36 DUE TO THE UNFAVORABLE ENVIRONMENT. MODEL GUIDANCE IS IN GOOD AGREEMENT LENDING GOOD CONFIDENCE TO THE JTWC FORECAST TRACK, WHICH CLOSELY FOLLOWS CONSENSUS.// NNNN NNNN