The 4 a.m. Global Tracks Software model shows hurricane force winds up into the piney woods of East TexasThe Hurricane Center 4 a.m. Houston time statement:
...RITA HAS TURNED A LITTLE TO THE RIGHT DURING THE PAST SEVERAL HOURS
AND THE INITIAL MOTION IS NOW 285/8. RAWINSONDE DATA SHOWS A
STRONG MID-LEVEL RIDGE CENTERED OVER TEXAS. LARGE-SCALE MODELS
FORECAST THIS RIDGE TO SHIFT EASTWARD INTO THE SOUTHEASTERN STATES
AND THE EASTERN GULF OF MEXICO DURING THE NEXT 48 HR. THIS SHOULD
ALLOW RITA TO TURN MORE NORTHWARD WITH TIME. THE TRACK GUIDANCE IS
NOW CLUSTERED AROUND A LANDFALL BETWEEN THE SABINE RIVER AND
MATAGORDA TEXAS IN 48-60 HR...WITH A NET EASTWARD SHIFT OF THE
GUIDANCE SINCE THE LAST PACKAGE. THE NEW FORECAST TRACK IS ALSO
SHIFTED EASTWARD ABOUT 30 N MI...CALLING FOR LANDFALL NEAR THE
BOLIVAR PENINSULA AND GALVESTON BAY. HOWEVER...IT SHOULD BE NOTED
THAT THE NEW TRACK IS ALONG THE LEFT OR WEST SIDE OF THE ENVELOPE OF
GUIDANCE.
THE INTENSITY FORECAST REMAINS SOMEWHAT PROBLEMATIC. FIRST...THE
MORE NORTHERLY TRACK WILL LIKELY KEEP RITA OVER THE LOOP CURRENT
LONGER THAN PREVIOUSLY EXPECTED...SO THE EFFECT OF LOWER OCEAN HEAT
CONTENT MAY BE SOMEWHAT LESS THAN PREVIOUSLY EXPECTED IN THE FIRST
24 HR OR SO. SECOND...THE GFS AND SHIP MODELS FORECAST SIGNIFICANT
SHEAR OVER RITA AFTER 24 HR...WHICH RESULTS IN SHIPS CALLING FOR
SIGNIFICANT WEAKENING. SHEAR ANALYSES FROM CIMSS AT THE UNIVERSITY
OF WISCONSIN SHOW ABOUT 12 KT OF SOUTHERLY SHEAR CAUSED BY AN
UPPER-LEVEL ANTICYCLONE EAST OF RITA...AND THE LARGE-SCALE MODELS
SUGGEST THIS PATTERN WILL CONTINUE UNTIL LANDFALL. HOWEVER...THE
GFS AND SHIPS MAY BE OVERDOING THE SHEAR. FINALLY...THERE WILL BE
AT LEAST ONE AND POSSIBLE MORE CONCENTRIC EYEWALL CYCLES BEFORE
LANDFALL. THE INTENSITY FORECAST IS BASED ON THE PREMISE THAT
SHEAR AND REDUCED OUTFLOW WILL CAUSE A GRADUAL WEAKENING...
ESPECIALLY AFTER RITA MOVES WEST OF THE LOOP CURRENT IN 24-36 HR.
SUPERIMPOSED ON TOP OF THIS WILL BE FLUCTUATIONS CAUSED BY
CONCENTRIC EYEWALL CYCLES. THE NEW INTENSITY FORECAST IS AN UPDATE
OF THE PREVIOUS FORECAST...CALLING FOR SLOW OVERALL WEAKENING BUT
NOT AS MUCH AS SHOWN BY SHIPS.
Comments
Post a Comment