824 
 WTNT44 KNHC 291433
 TCDAT4
  
 TROPICAL STORM DON DISCUSSION NUMBER   8
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042011
 1000 AM CDT FRI JUL 29 2011
  
 SATELLITE IMAGES SHOW THAT DON HAS BECOME A LITTLE BETTER ORGANIZED
 THIS MORNING WITH INCREASED CONVECTIVE BANDING AROUND THE CENTRAL
 CONVECTION...ESPECIALLY IN THE SOUTHERN SEMICIRCLE.  HOWEVER...THE
 STORM CONTINUES TO EXPERIENCE 10-15 KT OF NORTHERLY VERTICAL WIND
 SHEAR...WITH AN ELONGATED OVERALL CLOUD PATTERN AND A STREAM OF ARC
 CLOUDS IN THE EASTERN AND NORTHEASTERN QUADRANTS OF THE CYCLONE.
 AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT HAS REPORTED 850 MB
 FLIGHT-LEVEL WINDS OF 51 KT...AND THE CENTRAL PRESSURE ESTIMATED
 FROM THE AIRCRAFT DATA IS NEAR 1002 MB.  THE INITIAL INTENSITY
 REMAINS 45 KT.
  
 THE INITIAL MOTION IS NOW 300/12.  DEEP-LAYER RIDGING OVER THE
 SOUTHEASTERN UNITED STATES SHOULD STEER DON GENERALLY
 WEST-NORTHWESTWARD UNTIL THE CYCLONE DISSIPATES OVER LAND IN
 36-48 HR.  THE NEW FORECAST TRACK HAS CHANGED LITTLE FROM THE
 PREVIOUS TRACK AND IS NEAR THE CENTER OF THE TRACK GUIDANCE
 ENVELOPE.
  
 DON SHOULD CONTINUE TO EXPERIENCE MODERATE SHEAR UNTIL THE CENTER
 MAKES LANDFALL IN ABOUT 18 HR.  IN ADDITION...WATER VAPOR IMAGERY
 AND MICROWAVE PRECIPITABLE WATER DATA SHOW DRY AIR CLOSE TO THE
 WESTERN SIDE OF DON.  THIS COMBINATION SHOULD CONTINUE TO IMPEDE
 SIGNIFICANT STRENGTHENING BEFORE LANDFALL...AND THUS THE INTENSITY
 FORECAST SHOWS ONLY SLIGHT STRENGTHENING.  DON SHOULD WEAKEN
 STEADILY AFTER LANDFALL...AND THE SYSTEM IS EXPECTED TO DISSIPATE
 COMPLETELY BY 48 HR IN AGREEMENT WITH THE DYNAMICAL MODEL GUIDANCE.
  
 INTERESTS IN EXTREME NORTHEAST MEXICO SHOULD CONTINUE TO CLOSELY
 MONITOR THE PROGRESS OF DON. ANY SMALL DEVIATION TO THE SOUTH OF
 THE FORECAST TRACK COULD NECESSITATE THE ISSUANCE OF WARNINGS FOR
 THE EXTREME NORTHEASTERN COAST OF MEXICO.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  29/1500Z 26.2N  94.9W   45 KT  50 MPH
  12H  30/0000Z 26.8N  96.7W   50 KT  60 MPH
  24H  30/1200Z 27.7N  99.1W   35 KT  40 MPH...INLAND
  36H  31/0000Z 28.3N 101.6W   25 KT  30 MPH...INLAND
  48H  31/1200Z...DISSIPATED
  
 $$
 FORECASTER BEVEN