WDPN31 PGTW 100300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 06W (NOUL) WARNING NR 29// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 06W (NOUL), LOCATED APPROXIMATELY 196 NM NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTH-NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS THE SUPER TYPHOON HAS MAINTAINED A SHARP WELL- DEFINED 20-NM EYE WHICH SUPPORTS THE CURRENT POSITION WITH HIGH CONFIDENCE. THE INITIAL INTENSITY HAS BEEN INCREASED TO 140 KNOTS BASED ON CONSENSUS DVORAK INTENSITY ESTIMATES OF T7.0 (140 KNOTS) FROM ALL REPORTING AGENCIES. UPPER-LEVEL ANALYSIS CONTINUES TO SHOW RADIAL OUTFLOW WITH LOW VERTICAL WIND SHEAR (VWS) WHICH, COMBINED WITH SEA SURFACE TEMPERATURES (SST) ABOVE 30 CELSIUS, IS CREATING A FAVORABLE ENVIRONMENT FOR THE CURRENT INTENSIFICATION. STY NOUL IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP LAYERED SUB- TROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. FAVORABLE ENVIRONMENTAL CONDITIONS WILL PERSIST OVER THE NEXT 06 TO 12 HOURS; HOWEVER, DUE TO FRICTION EFFECTS AS THE SYSTEM SWIRLS OFF THE NORTHEASTERN TIP OF LUZON, STY 06W IS EXPECTED TO MAINTAIN THE CURRENT SUPER TYPHOON STRENGTH AND WILL SLOWLY BEGIN ITS WEAKENING TREND BY TAU 12. CONCURRENTLY, THE SYSTEM IS FORECAST TO TURN POLEWARD AS AN APPROACHING MID-LATITUDE TROUGH WEAKENS THE STEERING STR. BY TAU 24, THE COMBINED EFFECTS OF INCREASING VWS AND DECREASING SST WILL ERODE THE CONVECTIVE STRUCTURE AND FURTHER WEAKEN THE SYSTEM. AS STY 06W ACCELERATES AND BECOMES FURTHER EMBEDDED INTO THE MID-LATITUDE WESTERLIES, THE SYSTEM WILL BROADEN AND GAIN FRONTAL CHARACTERISTICS AS IT BEGINS EXTRA-TROPICAL TRANSITION (ETT) AFTER TAU 48. THE SYSTEM IS FORECAST TO COMPLETE ETT BY TAU 72. C. IN THIS EXTENDED PERIOD, DUE TO UNFAVORABLE UPPER-LEVEL ENVIRONMENT AND EXPECTED ETT, THE SYSTEM IS FORECAST TO GENERALLY WEAKEN AS THE STRONGEST WINDS ASSOCIATED WITH THE SYSTEM MIGRATE FROM THE CENTER OF THE SYSTEM INTO THE DEVELOPING FRONTS. THE SYSTEM IS EXPECTED TO BECOME A GALE FORCE, MID-LATITUDE LOW BY THE END OF FORECAST PERIOD AS IT TRACKS ALONG THE SOUTHERN COAST OF CENTRAL JAPAN AND FURTHER ON INTO THE NORTHWESTERN PACIFIC OCEAN.// NNNN