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Tropical Depression EIGHT (Text)

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TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082011
1100 AM EDT FRI AUG 19 2011
 
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT FOUND THAT THE
WELL-DEFINED CENTER OF TROPICAL DEPRESSION EIGHT WAS ABOUT 30 N MI
NORTHEAST OF THE POSITION IN EARLIER ADVISORIES.  HOW MUCH OF THIS
SHIFT IS DUE TO A CHANGE IN THE MOTION AND HOW MUCH IS DUE TO
REFORMATION OF THE CENTER IS NOT OBVIOUS IN THE DATA CURRENTLY
AVAILABLE.  THE AIRCRAFT HAS REPORTED CENTRAL PRESSURES OF
1004-1005 MB...850 MB FLIGHT-LEVEL WINDS OF 40 KT...AND RELIABLE
SFMR SURFACE WIND ESTIMATES OF 30-35 KT.  THESE DATA SUGGEST THAT
THE CYCLONE IS JUST BELOW TROPICAL-STORM STRENGTH...AND THE INITIAL
INTENSITY REMAINS 30 KT.

THE INITIAL MOTION IS A RATHER UNCERTAIN 275/9.  A LOW/MID-LEVEL
RIDGE OVER THE GULF OF MEXICO AND THE NORTHERN GULF COAST IS
EXPECTED TO GRADUALLY STRENGTHEN DURING THE NEXT 48-72 HR...AND
THIS SHOULD STEER THE CYCLONE GENERALLY WESTWARD TO WEST-
NORTHWESTWARD THROUGH ITS LIFETIME.  THE NEW FORECAST TRACK IS
PARALLEL TO...BUT SHIFTED NORTH OF...THE PREVIOUS FORECAST AND LIES
NEAR THE CENTER OF THE TRACK GUIDANCE ENVELOPE.  THE FORECAST TRACK
HAS THE CENTER PASSING NEAR THE BAY ISLANDS OF HONDURAS TONIGHT AND
OVER THE COAST OF BELIZE SATURDAY OR SATURDAY NIGHT.

THE NEW FORECAST TRACK ALLOWS THE CYCLONE TO SPEND MORE TIME OVER
WATER THAN PREVIOUSLY EXPECTED...AND THIS REQUIRES REVISING THE
INTENSITY FORECAST UPWARD.  THE NEW INTENSITY FORECAST CALLS FOR
THE SYSTEM TO BECOME A TROPICAL STORM IN 12 HR OR LESS AND TO REACH
A PEAK INTENSITY OF 45 KT NEAR THE TIME OF LANDFALL IN BELIZE. 
THIS FORECAST IS A COMPROMISE BETWEEN THE WEAKER GFDL/HWRF MODELS
AND THE STRONGER SHIPS/LGEM MODELS.

THE NEW FORECAST REQUIRES SIGNIFICANT CHANGES TO THE WATCHES AND
WARNINGS AT THIS TIME.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  19/1500Z 16.1N  83.7W   30 KT  35 MPH
 12H  20/0000Z 16.3N  85.0W   35 KT  40 MPH
 24H  20/1200Z 16.7N  86.8W   40 KT  45 MPH
 36H  21/0000Z 17.1N  88.6W   45 KT  50 MPH...INLAND
 48H  21/1200Z 17.5N  90.5W   30 KT  35 MPH...INLAND
 72H  22/1200Z 18.0N  94.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  23/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN
 
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