MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 26W (MANGKHUT) WARNING NR 34// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 26W (MANGKHUT), LOCATED APPROXIMATELY 246 NM NORTH- NORTHWEST OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED ON RECENT FIXES FROM RJTD AND PGTW WITH HIGH CONFIDENCE. THE INTENSITY IS CONSISTENT WITH A CONSENSUS OF SUBJECTIVE DVORAK AND OBJECTIVE INTENSITY ESTIMATES FROM MULTIPLE REPORTING AGENCIES. TY 26W HAS REORGANIZED A BIT OVER THE PAST SIX HOURS AFTER EMERGING INTO THE NORTHERN PORTION OF THE SOUTH CHINA SEA FOLLOWING PASSAGE OVER THE ISLAND OF LUZON. THE LARGE SYSTEM IS TRACKING WEST-NORTHWESTWARD ALONG THE PERIPHERY OF A DEEP-LAYERED SUBTROPICAL STEERING RIDGE TO THE NORTH. 3. FORECAST REASONING. A. NEAR-TERM FORECAST INTENSITIES HAVE BEEN REDUCED FROM THE PREVIOUS WARNING, CONSISTENT WITH NUMERICAL MODEL GUIDANCE, AND THE TRACK HAS SHIFTED SLIGHTLY TO THE NORTH. HOWEVER, THERE IS NO SIGNIFICANT CHANGE TO THE OVERALL FORECAST PHILOSOPHY. B. TY 26W WILL CONTINUE TO TRACK WEST-NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE TO THE NORTH THROUGHOUT THE 72 HOUR FORECAST PERIOD. ALTHOUGH THE PREVIOUSLY-DISRUPTED CIRCULATION IS CONTINUING TO RECONSOLIDATE, LOW VERTICAL WIND SHEAR, FAVORABLE UPPER-LEVEL OUTFLOW AND PASSAGE OVER WARM WATER SHOULD ENABLE THE SYSTEM TO MAINTAIN INTENSITY IN THE NEAR-TERM. THE SYSTEM IS EXPECTED TO WEAKEN DUE TO LAND INTERACTION, LIKELY BEGINNING AROUND TAU 24. PASSAGE OVER LAND IN THE MEDIUM RANGE WILL RESULT IN DISSIPATION BY TAU 72. NUMERICAL MODELS ARE IN VERY GOOD AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC TRACK.// NNNN NNNN