000
WTNT42 KNHC 271431
TCDAT2
TROPICAL STORM EARL DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST FRI AUG 27 2010
 
THE OVERALL PATTERN HAS NOT CHANGED MUCH DURING THE PAST SEVERAL
HOURS. EARL CONTINUES TO HAVE A LARGE CIRCULATION...MODERATE BANDS
OF DEEP CONVECTION AND FAIR OUTFLOW. DVORAK SATELLITE ESTIMATES
STILL SUPPORT AN INITIAL INTENSITY OF 40 KNOTS. THE OCEAN AND THE
ATMOSPHERE APPEAR TO BE FAVORABLE FOR INTENSIFICATION...AND THIS IS
REFLECTED IN THE INTENSITY GUIDANCE WHICH ARE ALL SHOWING
STRENGTHENING. IN FACT...BOTH GFDL AND HWRF ARE AGGRESSIVE IN
MAKING EARL AN INTENSE HURRICANE IN 5 DAYS.  ACCORDINGLY...THE
OFFICIAL FORECAST SHOWS EARL BECOMING A MAJOR HURRICANE BY THE END
OF THE FORECAST PERIOD.
 
EARL IS MOVING TOWARD THE WEST OR 270 DEGREES AT 15 KNOTS EMBEDDED
WITHIN THE EASTERLY FLOW AROUND THE SOUTH SIDE OF A NARROW
SUBTROPICAL RIDGE.  THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR
THE NEXT DAY OR TWO. THEREAFTER...THE CYCLONE WILL BEGIN TO
APPROACH A WEAKNESS IN THE SUBTROPICAL RIDGE AND SHOULD BEGIN TO
TURN MORE TO THE WEST-NORTHWEST AND NORTHWEST WITH A DECREASE IN
FORWARD SPEED. THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST FOR
THE FIRST 48 HOURS SINCE THE STEERING CURRENTS ARE WELL
ESTABLISHED. ONCE THE CYCLONE BEGINS TO APPROACH 60 DEGREES WEST...
THE TRACK MODELS ARE IN LESS AGREEMENT AND THERE IS LESS CONFIDENCE
IN THE FORECAST. THE OFFICIAL FORECAST IS IN BETWEEN THE GFS AND
THE ECMWF AND IS A LITTLE BIT SOUTH OF THE PREVIOUS ONE.
 
A DEVIATION TO THE SOUTH OF THE CURRENT FORECAST TRACK COULD BRING
EARL INTO THE NORTHERN LEEWARD ISLANDS. WITH THE WEEKEND
COMING...RESIDENTS IN THESE ISLANDS SHOULD CLOSELY MONITOR THE
PROGRESS OF EARL.
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/1500Z 15.7N  43.6W    40 KT
 12HR VT     28/0000Z 15.8N  45.8W    45 KT
 24HR VT     28/1200Z 16.3N  49.5W    50 KT
 36HR VT     29/0000Z 16.8N  53.0W    60 KT
 48HR VT     29/1200Z 17.5N  56.0W    70 KT
 72HR VT     30/1200Z 18.8N  60.5W    80 KT
 96HR VT     31/1200Z 21.5N  64.0W    90 KT
120HR VT     01/1200Z 25.0N  67.0W   100 KT
 
$$
FORECASTER AVILA