936 
 WTNT42 KNHC 281436
 TCDAT2
 TROPICAL STORM EARL DISCUSSION NUMBER  13
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
 1100 AM AST SAT AUG 28 2010
  
 ALTHOUGH THE CIRCULATION CONTINUES TO BE LARGE AND VIGOROUS AND THE
 AMOUNT OF DEEP CONVECTION HAS INCREASED SINCE YESTERDAY...VISIBLE
 IMAGES INDICATE THAT CENTER HAS BECOME EXPOSED AND IS LOCATED ON
 THE NORTHWESTERN SIDE OF THE DEEP CONVECTION. THIS HAS RESULTED
 FROM SOME MODEST NORTHERLY SHEAR CAUSED BY THE OUTFLOW OF LARGER
 HURRICANE DANIELLE. ALTHOUGH THE CYCLONE IS LESS ORGANIZED THAN
 EARLIER TODAY...T-NUMBERS HAVE NOT CHANGED MUCH AND THE INITIAL
 INTENSITY IS KEPT AT 50 KNOTS...BUT THE INTENSITY COULD BE LOWER. 
 THE CURRENT NORTHERLY SHEAR IS EXPECTED TO ABATE SOON AS DANIELLE
 MOVES NORTHWARD AND...IN FACT...MOST OF THE GLOBAL MODELS SHOW THE
 UPPER-LEVEL FLOW BECOMING MORE FAVORABLE FOR INTENSIFICATION BY
 SUNDAY.  THIS FLOW PATTERN...IN COMBINATION WITH A WARM OCEAN ALONG
 THE TRACK...WOULD RESULT IN INTENSIFICATION. EARL IS FORECAST TO
 BECOME A HURRICANE BY SUNDAY WITH A STEADY INTENSIFICATION
 THEREAFTER.
  
 EARL IS MOVING TOWARD THE WEST OR 275 DEGREES AT ABOUT 16 OR 17
 KNOTS STEERED BY THE FLOW TO THE SOUTH OF A SUBTROPICAL RIDGE.
 HOWEVER...IN A DAY OR SO...EARL WILL BE APPROACHING THE WESTERN
 EDGE OF THE RIDGE AND THE CYCLONE SHOULD BEGIN TO TURN MORE TO THE
 WEST-NORTHWEST AND NORTHWEST. THE TRACK MODELS DIVERGE BEYOND 48
 HOURS BUT ONCE AGAIN...THE OFFICIAL FORECAST AND THE GUIDANCE
 ENVELOPE HAVE SHIFTED A LITTLE BIT SOUTHWARD AND WESTWARD.
 NEVERTHELESS...THE EXPECTED STEERING PATTERN STILL FAVORS A
 GRADUAL TURN TO THE WEST-NORTHWEST DURING THE NEXT DAY OR TWO. AT
 THIS TIME...IT IS NOT NECESSARY TO CHANGE THE TROPICAL STORM WATCH
 FOR THE NORTHERN LEEWARD ISLANDS BUT A DEVIATION OF THE TRACK TO
 THE WEST WOULD REQUIRE ADDITIONAL WATCHES OR WARNINGS.
  
 A NOAA-P3 AIRCRAFT RESEARCH MISSION WILL PROBABLY CHECK THE SYSTEM
 LATER TODAY WHILE A NOAA GULFSTREAM JET SAMPLES THE ENVIRONMENT.
 THE FIRST AIR FORCE RECONNAISSANCE AIRCRAFT INTO EARL IS SCHEDULED
 FOR EARLY SUNDAY.
  
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      28/1500Z 16.0N  51.8W    50 KT
  12HR VT     29/0000Z 16.1N  54.3W    55 KT
  24HR VT     29/1200Z 17.0N  57.5W    65 KT
  36HR VT     30/0000Z 17.8N  60.0W    75 KT
  48HR VT     30/1200Z 18.7N  62.0W    85 KT
  72HR VT     31/1200Z 21.5N  66.0W    95 KT
  96HR VT     01/1200Z 25.0N  69.0W   100 KT
 120HR VT     02/1200Z 30.0N  71.0W   100 KT
  
 $$
 FORECASTER AVILA