000
WTNT42 KNHC 291457
TCDAT2
HURRICANE EARL DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL072010
1100 AM AST SUN AUG 29 2010
 
EARL HAS BECOME MUCH BETTER ORGANIZED IN SATELLITE IMAGERY WITH
SEVERAL BANDS OF THUNDERSTORMS WRAPPING AROUND THE CENTER AND A
DEVELOPING CDO.  AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
FOUND 850 MB FLIGHT-LEVEL WINDS OF 81 KT AND SFMR SURFACE WINDS OF
64 KT EARLIER THIS MORNING.  THESE MEASUREMENTS SUPPORTED THE
EARLIER UPGRADE TO HURRICANE STATUS. 
 
NORTHEASTERLY SHEAR SHOULD CONTINUE TO DECREASE TODAY...AND THE
UPPER-LEVEL ENVIRONMENT APPEARS QUITE FAVORABLE FOR INTENSIFICATION
DURING THE NEXT FEW DAYS.  THE SHIPS...LGEM...AND GFDL MODELS
SUPPORT STEADY STRENGTHENING...AND THE OFFICIAL FORECAST IS NEAR
THE HIGH END OF THE GUIDANCE THROUGH 36 HOURS...PREDICTING THAT
EARL WILL ATTAIN MAJOR HURRICANE DURING THAT TIME.  THEREAFTER...
THE NHC FORECAST IS CLOSE TO A BLEND OF THE MORE AGGRESSIVE GFDL
AND THE LOWER SHIPS/LGEM MODELS.
 
THE HURRICANE IS STILL MOVING WESTWARD OR 280/15 KT.  EARL IS
EXPECTED TO TURN WEST-NORTHWESTWARD AND SLOW DOWN AS IT APPROACHES
THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE DURING THE NEXT DAY
OR SO. THE HURRICANE IS FORECAST TO TURN NORTHWESTWARD IN 2-3 DAYS
AS IT ROUNDS THE RIDGE. LATE IN THE FORECAST PERIOD...A TROUGH IS
FORECAST TO MOVE ACROSS THE GREAT LAKES....WHICH SHOULD RESULT IN 
A NORTHWARD MOTION.  THE TRACK GUIDANCE IS IN GOOD AGREEMENT...BUT
THE GLOBAL MODELS ARE MUCH FASTER THAN THE REGIONAL HURRICANE
MODELS AT DAYS 4 AND 5.  THE NHC TRACK IS ALONG THE SOUTHERN SIDE
OF THE GUIDANCE ENVELOPE FOR THE FIRST 36 HOURS AND LEANS TOWARD
THE FASTER SOLUTION OF THE GLOBAL MODELS AT DAYS 4 AND 5. 

PERSONS IN THE LEEWARD ISLANDS SHOULD REMEMBER THAT THE HURRICANE IS
NOT A POINT SINCE HAZARDS EXTEND WELL AWAY FROM THE CENTER. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/1500Z 17.2N  58.4W    65 KT
 12HR VT     30/0000Z 17.6N  60.4W    75 KT
 24HR VT     30/1200Z 18.5N  62.7W    90 KT
 36HR VT     31/0000Z 19.6N  64.5W   100 KT
 48HR VT     31/1200Z 21.1N  66.3W   105 KT
 72HR VT     01/1200Z 25.2N  69.8W   110 KT
 96HR VT     02/1200Z 31.0N  72.0W   110 KT
120HR VT     03/1200Z 37.0N  71.5W   100 KT
 
$$
FORECASTER BROWN/BERG