MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 26W (MANGKHUT) WARNING NR 30// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON 26W (MANGKHUT), LOCATED APPROXIMATELY 297 NM EAST- NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT 15 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES CLOUD TOPS IN STY 26W HAVE WARMED SLIGHTLY OVER THE PAST SIX HOURS, AND THE SYSTEM HAS BECOME OBLONG, WITH A THINNER BAND OF CONVECTION TO THE NORTHWEST. A 140444Z AMSR2 89GHZ MICROWAVE IMAGE REVEALS CONCENTRIC EYEWALLS AND THE BEGINNING OF ANOTHER EYEWALL REPLACEMENT CYCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE 30NM EYE. THE INITIAL INTENSITY IS ASSESSED AT 145 KNOTS, BETWEEN THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T7.5 (155 KTS), THE RJTD ESTIMATE OF T7.0 (140 KTS), AND THE KNES ESTIMATE OF T6.5 (127 KTS), BASED ON THE WARMING CLOUD TOPS AND INITIATION OF THE ERC, WHICH WILL LEAD TO WEAKENING AS THE PRIMARY EYEWALL IS STARVED OF INFLOW AND THE OUTER RING FURTHER FROM THE CENTER BECOMES THE DOMINANT EYEWALL. A 140459Z SATCON ESTIMATE OF 142 KTS SUPPORTS THE INTENSITY ASSESSMENT. ENVIRONMENTAL ANALYSIS SHOWS THAT THE SYSTEM CONTINUES TO LIE IN A FAVORABLE ENVIRONMENT WITH STRONG RADIAL OUTFLOW, BUT THE TUTT CELL FAR TO THE EAST IS NO LONGER ENHANCING ITS OUTFLOW. ADDITIONALLY, A WEAK UPPER-LEVEL ANTICYCLONE CONTINUES TO IMPINGE UPON OUTFLOW IN THE NORTHWESTERN QUADRANT. VERTICAL WIND SHEAR REMAINS LOW AND SSTS AND OHC REMAIN SUPPORTIVE. STY 26W CONTINUES TO TRACK TO THE NORTHWEST UNDER THE STEERING INFLUENCE OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. STY 26W WILL TRACK WEST-NORTHWESTWARD THROUGH TAU 72 UNDER THE INFLUENCE OF THE STR TO THE NORTHEAST. THE SYSTEM IS FORECAST TO MAKE LANDFALL AS A VERY INTENSE SUPER TYPHOON ALONG THE NORTHEAST COAST OF LUZON JUST AFTER TAU 12. ADDITIONAL NEAR-TERM WEAKENING IS POSSIBLE BEFORE LANDFALL AS STY 26W PROCEEDS THROUGH ITS EYEWALL REPLACEMENT CYCLE. AFTER MAKING LANDFALL, THE SYSTEM WILL WEAKEN SIGNIFICANTLY AS IT INTERACTS WITH THE MOUNTAINOUS TERRAIN OF NORTHERN LUZON. STY 26W WILL REEMERGE INTO THE SOUTH CHINA SEA (SCS) JUST PRIOR TO TAU 24 AS A 105 KT SYSTEM. A PERIOD OF SLOW INTENSIFICATION IS FORECAST IN THE SCS BETWEEN TAUS 24 AND 48 AS THE SYSTEM MOVES OVER WARM (28-29 CELSIUS) WATERS AND UPPER LEVEL OUTFLOW REMAINS FAVORABLE. STY 26W IS FORECAST TO MAKE LANDFALL BETWEEN HONG KONG AND THE LEIZHOU PENINSULA AFTER TAU 48, WITH HWRF THE NORTHERN OUTLIER MAKING LANDFALL CLOSER TO HONG KONG. DYNAMIC MODEL GUIDANCE IS IN EXTREMELY TIGHT AGREEMENT THROUGH TAU 72, WITH LESS THAN 15NM SPREAD AT LANDFALL, INCREASING TO 79NM AT TAU 48, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. C. AFTER TAU 72, STY 26W WILL CONTINUE ON A WEST-NORTHWESTWARD TO WESTWARD TRACK UNDER THE STEERING INFLUENCE OF THE AFOREMENTIONED STR, WEAKENING RAPIDLY OVER THE MOUNTAINOUS TERRAIN OF NORTHERN VIETNAM, CHINA, AND NORTHERN MYANMAR, DISSIPATING BY TAU 120. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT IN THE LATER TAUS, WITH SOME MODELS LOSING THE SYSTEM AND OTHERS BRINGING IT TO THE NORTHWEST. OVERALL HOWEVER, THERE IS HIGH CONFIDENCE IN THE OFFICIAL FORECAST THROUGH TAU 96, WITH LOW CONFIDENCE THEREAFTER.// NNNN NNNN