Sunday, August 27

Ernesto could be Category 3 at landfall

Here is the National Hurricane Center's 10 a.m. CDT discussion of Ernesto, which is now on a predicted path well out of the way of Louisiana.


Hurricane ERNESTO Forecast Discussion
HURRICANE ERNESTO DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL052006
1100 AM EDT SUN AUG 27 2006

ERNESTO'S CLOUD PATTERN IS STILL A BIT RAGGED-LOOKING BUT THERE ARE
SOME BANDING FEATURES OVER THE EASTERN SEMICIRCLE...AND CIRRUS
OUTFLOW IS EXPANDING OVER THE WESTERN PART OF THE CIRCULATION. THE
LAST AIRCRAFT-EXTRAPOLATED CENTRAL PRESSURE WAS 997 MB...SUGGESTING
THAT THERE HAS BEEN LITTLE OR NO STRENGTHENING OVER THE PAST
SEVERAL HOURS. WITH THE UPPER-LEVEL CYCLONE SHIFTING WESTWARD
TOWARD YUCATAN...THE SHEAR OVER ERNESTO IS QUICKLY DIMINISHING.
THUS THE PRIMARY CONSIDERATION IN THE INTENSITY FORECAST OVER THE
NEXT COUPLE OF DAYS WILL BE HOW MUCH THE TROPICAL CYCLONE INTERACTS
WITH LAND. ON THE CURRENT FORECAST TRACK...THE CENTER WOULD BE
OVER CUBA FROM HOUR 24 TO 48 HOURS. THIS SHOULD CAUSE SOME
WEAKENING AND THE OFFICIAL WIND SPEED FORECAST FOLLOWS THE DECAY
SHIPS MODEL RATHER CLOSELY. HOWEVER...AFTER THE CENTER MOVES INTO
THE SOUTHEASTERN GULF OF MEXICO...SIGNIFICANT RESTRENGTHENING IS
POSSIBLE. IT SHOULD BE NOTED THAT THE OFFICIAL FORECAST INTENSITY
AT 96 HOURS ASSUMES SOME WEAKENING DUE TO INTERACTION WITH LAND.
HOWEVER....ERNESTO COULD APPROACH CATEGORY 3 STATUS PRIOR TO THE
PROJECTED LANDFALL IN WESTERN FLORIDA.

INITIAL MOTION IS ESTIMATED AT 310/8. A CONTINUED NORTHWESTWARD
TRACK IS INDICATED BY MOST OF THE NUMERICAL GUIDANCE OVER THE NEXT
COUPLE OF DAYS. THIS WOULD TAKE ERNESTO OVER A SIGNIFICANT PORTION
OF CUBA. A MID-TROPOSPHERIC ANTICYCLONE OVER THE SOUTHEASTERN
UNITED STATES IS EXPECTED TO SHIFT EASTWARD AS A SHORTWAVE TROUGH
DROPS INTO THE LOWER MISSISSIPPI IN 3-5 DAYS. THIS SHOULD CAUSE A
MORE NORTHWARD HEADING LATER IN THE FORECAST PERIOD. THE 0600 UTC
RUNS OF THE GFS HAS SHIFTED A LITTLE TO THE WEST OF THE PREVIOUS
RUN BUT THE 0600 UTC NOGAPS HAS SHIFTED TO THE EAST. THE OFFICIAL
FORECAST TRACK IS NUDGED SLIGHTLY MORE TO THE RIGHT TO BE CLOSER TO
THE MODEL CONSENSUS. THIS IS EAST OF THE LATEST GFDL MODEL TRACK.

A TROPICAL STORM OR HURRICANE WATCH MAY BE REQUIRED FOR THE FLORIDA
KEYS AS EARLY AS 2100 UTC TODAY.


FORECAST POSITIONS AND MAX WINDS

INITIAL 27/1500Z 17.6N 73.7W 65 KT
12HR VT 28/0000Z 18.6N 74.9W 75 KT
24HR VT 28/1200Z 20.0N 76.5W 85 KT...INLAND
36HR VT 29/0000Z 21.5N 78.3W 75 KT...INLAND
48HR VT 29/1200Z 23.1N 80.3W 65 KT...INLAND
72HR VT 30/1200Z 25.5N 82.5W 85 KT
96HR VT 31/1200Z 28.0N 82.5W 80 KT...INLAND
120HR VT 01/1200Z 31.0N 81.0W 60 KT

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