MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 26W (MANGKHUT) WARNING NR 19// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 26W (MANGKHUT), LOCATED APPROXIMATELY 254 NM NORTH OF YAP, FSM, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A SYMMETRIC AND HIGHLY CONSOLIDATED SYSTEM WITH COMPACT FEEDER BANDS SPIRALING TIGHTLY INTO A SHARPLY-OUTLINED 23-NM EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE. THE INITIAL INTENSITY OF 140 KNOTS IS BASED ON EQUIVALENT DVORAK ESTIMATES OF T7.0 FROM PGTW AND RJTD. UPPER LEVEL ANALYSIS INDICATES STY 26W IS IN AN AREA OF LOW VERTICAL WIND SHEAR AND EXCELLENT RADIAL OUTFLOW WITH A STRONG EASTWARD CHANNEL INTO A TUTT CELL. ADDITIONALLY, ALONG TRACK SEA SURFACE TEMPERATURES IN THE PHILIPPINE SEA AT 28-30 CELSIUS ARE HIGHLY CONDUCIVE. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED EAST-WEST ORIENTED SUBTROPICAL RIDGE (STR) TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS WARNING. B. STY 26W WILL TRACK MORE WEST-NORTHWESTWARD AFTER TAU 12 AS THE STR WEAKENS IN RESPONSE TO AN APPROACHING MIDLATITUDE TROUGH. THE FAVORABLE ENVIRONMENTAL CONDITIONS WILL PERSIST AND SUPPORT CONTINUED INTENSIFICATION TO A PEAK OF 150 KNOTS BY TAU 36. AFTERWARD, REDUCED OUTFLOW AS THE SYSTEM MOVES AWAY FROM THE TUTT CELL WILL SLIGHTLY WEAKEN THE SYSTEM TO 135 KNOTS BY TAU 72 AS IT APPROACHES NORTHERN LUZON. CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK REMAINS HIGH BASED ON THE TIGHT GROUPING IN THE NUMERICAL MODEL GUIDANCE. C. AFTER TAU 72, STY MANGKHUT WILL CONTINUE ON A MORE NORTHWESTWARD TRAJECTORY UNDER THE STEERING INFLUENCE OF THE WEAKENED STR. THE CYCLONE WILL ENTER THE LUZON STRAIT AND PASS BETWEEN TAIWAN AND THE PHILIPPINES INTO THE SOUTH CHINA SEA. INTERACTION WITH LAND AND DIMINISHING OUTFLOW WILL PRIMARILY BE RESPONSIBLE FOR ITS GRADUAL DECAY. HOWEVER, BY TAU 120, THE SYSTEM WILL STILL BE A SOLID 80-KNOT TYPHOON WHEN IT MAKES LANDFALL TO THE WEST OF HONG KONG. THE TRACK GUIDANCE REMAINS IN TIGHT AGREEMENT WITH CTCX AS THE LONE LEFT-OF-TRACK OUTLIER. THERE IS ALSO HIGH CONFIDENCE IN THE EXTENDED JTWC FORECAST TRACK THAT IS LAID JUST RIGHT OF MODEL CONSENSUS TO OFFSET THE UNLIKELY CTCX SOLUTION.// NNNN NNNN