MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 26W (MANGKHUT) WARNING
NR 24//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUPER TYPHOON (STY) 26W (MANGKHUT), LOCATED APPROXIMATELY 668 NM
EAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 15 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS A 200NM DIAMETER CONVECTIVE CORE WITH A 27NM ROUND EYE AND
BANDING FEATURE. A 121709Z AMSR2 89GHZ IMAGE INDICATES AN ONGOING
EYEWALL REPLACEMENT CYCLE (ERC) WITH CONCENTRIC EYEWALLS AND
DISTINCT MOAT FEATURE EVIDENT. DESPITE THE ERC AND SLIGHT EROSION OF
THE INNER EYEWALL OVER THE NNE QUADRANT, THE SYSTEM HAS INTENSIFIED
SLIGHTLY TO 155 KNOTS, BASED ON A PGTW DVORAK ESTIMATE OF 7.5 (155
KNOTS) AND A RECENT SATCON ESTIMATE OF 156 KNOTS. UPPER-LEVEL
ANALYSIS CONTINUES TO INDICATE A VERY FAVORABLE ENVIRONMENT WITH
RADIAL OUTFLOW, ENHANCED BY A TUTT CELL TO THE EAST, AND LOW
VERTICAL WIND SHEAR. ADDITIONALLY, WARM SST (29-30C) AND HIGH OCEAN
HEAT CONTENT VALUES ARE VERY FAVORABLE. STY 26W IS TRACKING WESTWARD
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 THE FORECAST
PERIOD WITH LANDFALL ALONG THE NORTHEAST COAST OF LUZON BY TAU 48.
STY 26W WILL MAINTAIN STY INTENSITY THROUGH TAU 48 UNDER VERY
FAVORABLE ENVIRONMENTAL CONDITIONS. AFTER TAU 48, STY 26W WILL
WEAKEN SIGNIFICANTLY AS IT TRACKS OVER THE MOUNTAINOUS REGION OF
LUZON, RE-EMERGING OVER THE SOUTH CHINA SEA (SCS) NEAR TAU 60 NEAR
110 KNOTS.
C. AFTER TAU 72, STY MANGKHUT WILL CONTINUE ON A WEST-
NORTHWESTWARD TRAJECTORY UNDER THE STEERING INFLUENCE OF THE STR.
THE SYSTEM WILL TRACK ACROSS THE SCS JUST SOUTH OF HONG KONG MAKING
LANDFALL OVER SOUTHERN CHINA NEAR TAU 96. THE SYSTEM WILL WEAKEN BY
TAU 96 DUE TO INTERACTION WITH LAND WITH MORE RAPID WEAKENING AS IT
TRACKS INTO NORTHERN VIETNAM BY TAU 120. THE DYNAMIC MODEL GUIDANCE
AND ENSEMBLE MODEL GUIDANCE REMAINS IN EXCEPTIONALLY TIGHT AGREEMENT
LENDING HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.//
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