MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 21W (DOKSURI) WARNING NR 13// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 21W (DOKSURI), LOCATED APPROXIMATELY 100 NM NORTH- NORTHEAST OF DA NANG, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION OF THE LOW LEVEL CIRCULATION CENTER (LLCC) IS BASED ON A 141800Z INFRARED IMAGE AND RECENT SATELLITE FIXES FROM PGTW AND RJTD. THE CURRENT INTENSITY OF 90 KNOTS IS BASED ON A DVORAK ESTIMATE OF T5.0 (90 KNOTS) FROM PGTW. TY 21W HAS CONTINUED TO STEADILY INTENSIFY WHILE TRACKING WEST- NORTHWESTWARD ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE (STR). ANIMATED INFRARED SATELLITE IMAGERY SHOWS PERSISTENT DEEP CONVECTION ALONG THE SOUTHERN AND EASTERN PORTIONS OF THE LLCC. DOKSURI CONTINUES TO HAVE EXCELLENT EQUATORWARD UPPER LEVEL OUTFLOW. POLEWARD UPPER LEVEL OUTFLOW IS NOT AS IMPRESSIVE. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY DOKSURI WILL CONTINUE TRACKING GENERALLY WEST-NORTHWESTWARD ALONG THE PERIPHERY OF THE CURRENT STEERING RIDGE THROUGHOUT THE FORECAST PERIOD. LOW VERTICAL WIND SHEAR (10-15 KNOTS), FAVORABLE EQUATORWARD OUTFLOW IN THE UPPER LEVELS AND HIGH SEA SURFACE TEMPERATURES (30-31 CELSIUS) WILL SUPPORT MAINTAINING CURRENT INTENSITY THROUGH TAU 12. TY 21W WILL MAKE LANDFALL SHORTLY BEFORE TAU 12 AND WILL DISSIPATE STEADILY AND SLOW IN FORWARD SPEED AS IT MOVES INLAND. NUMERICAL MODELS ARE IN GOOD AGREEMENT, AND THE CURRENT JTWC OFFICIAL FORECAST LIES NEAR THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE.// NNNN NNNN