WDPN32 PGTW 220300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 17W (USAGI) WARNING NR 22// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 17W (USAGI), LOCATED APPROXIMATELY 208 NM EAST OF HONG KONG, HAS TRACKED WEST-NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS A RESURGENCE IN THE EYEWALL DEVELOPMENT OVER THE PAST THREE TO SIX HOURS AS THE SYSTEM HAS STARTED TO APPROACH THE COAST OF CHINA. THE INTENSITY HAS BEEN MAINTAINED AT 100 KNOTS BASED ON THE WEAKENING TREND IN THE FIRST FEW HOURS FROM THE 211800Z FORECAST WITH DVORAK ESTIMATES SUPPORTING THE INTENSITY. UPPER LEVEL ANALYSIS INDICATES THE POINT- SOURCE ANTICYCLONE HAS SHIFTED OVER TOWARDS COASTAL CHINA, TO THE NORTHWEST OF THE SYSTEM, AND IS CREATING A WEAK PRESSURE GRADIENT ALONG THE NORTHERN PORTIONS OF TY 17W. THIS INCREASE IN UPPER LEVEL WINDS ALONG THE NORTHERN HALF OF THE SYSTEM CONTINUES TO HAMPER THE POLEWARD OUTFLOW CHANNEL. THE FAVORABLE EQUATORWARD OUTFLOW HAS BEEN SUPPORTING THE STRONG TYPHOON STRENGTHS OVER THE PAST FEW DAYS. THE CYCLONE CONTINUES TO TRACK ALONG THE SOUTHERN PERIPHERY OF A DEEP- LAYERED SUBTROPICAL RIDGE TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 17W IS FORECAST TO REMAIN ON A WEST-NORTHWESTWARD TRACK TOWARDS HONG KONG, AND IS EXPECTED TO MAKE LANDFALL WITHIN THE NEXT 24 HOURS. THE DECREASING UPPER LEVEL SUPPORT AND INCREASING LAND INTERACTIONS WILL LEAD TO A SLIGHT WEAKENING BEFORE LANDFALL WITH A RAPID WEAKENING AS LOW LEVEL INFLOW IS DISRUPTED BY MAINLAND CHINA. NUMERIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK.// NNNN