Tropical Storm MANGKHUT Advisory Fri Sep 14

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 26W (MANGKHUT) WARNING
NR 29//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   SUPER TYPHOON (STY) 26W (MANGKHUT), LOCATED APPROXIMATELY 350 NM
EAST-NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED NORTHWESTWARD AT
12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY INDICATES STY 26W HAS MAINTAINED ITSELF REMARKABLY WELL,
WITH VERY LITTLE CHANGE OVER THE PAST SIX HOURS. THE SYSTEM RETAINS
A 39 NM EYE FEATURE WHICH HAS BECOME MORE SYMMETRICAL SINCE THE
PREVIOUS ANALYSIS. DEEP CONVECTION COMPLETELY SURROUNDS THE EYE,
THOUGH THE CONVECTIVE SIGNATURE ON THE NORTHWEST SIDE OF THE CENTER
IS SLIGHTLY LESS INTENSE THAN THE OTHER QUADRANTS. A 132232Z SSMIS
89GHZ COLOR COMPOSITE IMAGE DEPICTS A VERY STRONG, SYMMETRIC EYEWALL
AND EXCELLENT SPIRAL BANDING. THE INITIAL POSITION IS PLACED WITH
HIGH CONFIDENCE BASED ON THE LARGE EYE FEATURE. THE INITIAL
INTENSITY IS ASSESSED WITH HIGH CONFIDENCE AT 150 KNOTS BASED ON A
BLEND OF DVORAK INTENSITY ESTIMATES RANGING FROM T7.0 (140 KNOTS) TO
T7.5 (155 KNOTS), AS WELL AS A SATELLITE CONSENSUS ESTIMATE OF 152
KNOTS. ENVIRONMENTAL ANALYSIS SHOWS THAT THE SYSTEM CONTINUES TO LIE
IN A FAVORABLE ENVIRONMENT WITH STRONG RADIAL OUTFLOW, THOUGH THE
PREVIOUS TAP INTO A TUTT CELL TO THE EAST APPEARS TO HAVE WEAKENED
OVER THE PAST SIX HOURS. ADDITIONALLY, A WEAK UPPER-LEVEL
ANTICYCLONE HAS DEVELOPED TO THE NORTHWEST OF THE SYSTEM, SLIGHTLY
IMPINGING OUTFLOW IN THIS QUADRANT, AS EVIDENCED BY THE WEAKER
CONVECTIVE SIGNATURE IN THIS QUADRANT. VWS REMAINS LOW AND SSTS AND
OHC REMAIN SUPPORTIVE. STY 26W CONTINUES TRACKING 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 THE STR TO THE NORTHEAST. THE SYSTEM IS FORECAST TO
MAKE LANDFALL AS A VERY INTENSE SUPER TYPHOON ALONG THE NORTHEAST
COAST OF LUZON NEAR TAU 20. SLIGHT WEAKENING IN THE NEAR-TERM IS
EXPECTED AS RECENT MICROWAVE IMAGERY AND EXPERIMENTAL MODEL PRODUCTS
ARE SHOWING AN INCREASING CHANCE OF ANOTHER EYEWALL REPLACEMENT
CYCLE (ERC) OCCURRING PRIOR TO LANDFALL. AFTER MAKING LANDFALL, THE
SYSTEM WILL WEAKEN SIGNIFICANTLY AS IT INTERACTS WITH THE TERRAIN
FEATURES OF NORTHERN LUZON. STY 26W WILL REEMERGE INTO THE SOUTH
CHINA SEA NEAR TAU 30 AS A 110 KNOT SYSTEM. A PERIOD OF SLOW
INTENSIFICATION IS FORECAST IN THE SCS BETWEEN TAUS 36 AND 48 AS THE
SYSTEM MOVES OVER WARM WATERS, FREE OF TERRAIN INFLUENCES. THE UPPER
LEVEL ENVIRONMENT REMAINS GENERALLY FAVORABLE THROUGH TAU 72.
DYNAMIC MODEL GUIDANCE IS IN EXTREMELY TIGHT AGREEMENT THROUGH TAU
72, WITH LESS THAN 25NM SPREAD AT LANDFALL, INCREASING TO 115NM AT
TAU 72, LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST.
   C. AFTER TAU 72, STY MANGKHUT WILL CONTINUE ON A WEST-
NORTHWESTWARD TO WESTWARD TRACK UNDER THE STEERING INFLUENCE OF THE
AFOREMENTIONED STR. THE SYSTEM WILL TRACK ACROSS THE SCS JUST SOUTH
OF HONG KONG MAKING LANDFALL OVER SOUTHERN CHINA PRIOR TO TAU 72.
THE SYSTEM WILL WEAKEN RAPIDLY AS IT TRACKS ACROSS NORTHERN VIETNAM
AND MYANMAR BY TAU 120. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT
IN THE LATER TAUS, PARTICULARLY AFTER TAU 96, WITH MANY MODELS
LOSING THE VORTEX COMPLETELY WHILE OTHERS TAKE THE SYSTEM EITHER
NORTHWEST OR NORTH. OVERALL HOWEVER, THERE IS HIGH CONFIDENCE IN THE
OFFICIAL FORECAST THROUGH TAU 96, WITH LOW CONFIDENCE THEREAFTER.//
NNNN
NNNN