930 
 WTNT42 KNHC 312043
 TCDAT2
 HURRICANE EARL DISCUSSION NUMBER  26
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
 500 PM AST TUE AUG 31 2010
  
 ALTHOUGH THE SATELLITE PRESENTATION IS NOT AS IMPRESSIVE AS IT WAS
 EARLIER...A RECONNAISSANCE PLANE AROUND 1700 UTC REPORTED A MINIMUM
 PRESSURE OF 940 MB AND MAXIMUM FLIGHT-LEVEL WINDS OF 128 KNOTS.
 THESE DATA SUPPORT AN INITIAL INTENSITY OF 115 KNOTS.
 CURRENTLY...THERE IS SOME SOUTHWESTERLY SHEAR DISRUPTING THE
 UPPER-LEVEL OUTFLOW OVER THE WESTERN SEMICIRCLE OF EARL.  THIS SHEAR
 IS CAUSED BY A WEAK UPPER-LOW OR TROUGH OVER THE EASTERN BAHAMAS AS
 OBSERVED ON WATER VAPOR IMAGES.  HOWEVER...MODELS WEAKEN THE UPPER
 LOW AS EARL MOVES AROUND IT...RESULTING IN A MORE FAVORABLE
 ENVIRONMENT. EARL IS EXPECTED TO MAINTAIN ITS CATEGORY FOUR
 INTENSITY FOR THE NEXT DAY OR TWO.
  
 EARL HAS BEGUN TO MOVE TOWARD THE NORTHWEST OR 305 DEGREES AT 12 OR
 13 KNOTS DURING THE PAST FEW HOURS. THE SUBTROPICAL HIGH THAT IS
 STEERING EARL TOWARD THE WEST-NORTHWEST OR NORTHWEST IS FORECAST TO
 GRADUALLY SHIFT EASTWARD AS A BROAD TROUGH BECOMES ESTABLISHED OVER
 THE EASTERN UNITED STATES. THIS PATTERN WILL FORCE EARL ON A MORE
 NORTHWESTERLY AND NORTHERLY TRACK FOR THE NEXT DAY OR TWO.
 THEREAFTER...EARL WILL REACH THE BASE OF THE MID-LATITUDE WESTERLIES
 AND WILL LIKELY TURN SHARPLY TO THE NORTHEAST WITH AN INCREASE IN
 FORWARD SPEED.  THIS IS THE SOLUTION UNANIMOUSLY PROVIDED BY TRACK
 GUIDANCE.  ONCE AGAIN THE OFFICIAL FORECAST HAS BEEN SHIFTED A FEW
 MILES TO THE WEST BEFORE 48 HOURS FOLLOWING THE TRENDS OF THE ECMWF
 AND THE GFS.
 
 GIVEN THE LARGE AREA OF TROPICAL STORM FORCE WINDS ASSOCIATED WITH
 EARL...AND THE NEW DEFINITION OF WATCHES AND WARNINGS...A HURRICANE
 AND TROPICAL STORM WATCH HAS BEEN ISSUED FOR A PORTION OF THE MID-
 ATLANTIC COAST.
 
 INTERESTS FROM VIRGINIA NORTHWARD TO NEW ENGLAND SHOULD MONITOR THE
 PROGRESS OF EARL. 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      31/2100Z 22.0N  68.8W   115 KT
  12HR VT     01/0600Z 23.3N  70.5W   115 KT
  24HR VT     01/1800Z 25.6N  72.8W   115 KT
  36HR VT     02/0600Z 28.0N  74.5W   115 KT
  48HR VT     02/1800Z 31.0N  75.5W   115 KT
  72HR VT     03/1800Z 36.0N  73.5W    95 KT
  96HR VT     04/1800Z 44.0N  65.0W    75 KT
 120HR VT     05/1800Z 56.0N  55.0W    50 KT...POST-TROP/EXTRATROP
  
 $$
 FORECASTER AVILA