336 
 WTNT44 KNHC 292036
 TCDAT4
  
 TROPICAL STORM DON DISCUSSION NUMBER   9
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042011
 400 PM CDT FRI JUL 29 2011
  
 SATELLITE IMAGERY SHOWS THAT DON REMAINS A SHEARED SYSTEM THIS
 AFTERNOON...WITH THE LOW-LEVEL CENTER NEAR THE NORTHEASTERN EDGE OF
 A DISORGANIZED MASS OF STRONG CONVECTION.  AN AIR FORCE RESERVE
 HURRICANE HUNTER PLANE MEASURED 56 KT FLIGHT-LEVEL WINDS AT 850 MB
 AND ESTIMATED SURFACE WINDS OF 46 KT WITH THE SFMR...BOTH IN THE
 NORTHEASTERN QUADRANT.  BASED ON THIS...THE INITIAL INTENSITY
 REMAINS 45 KT.  IT SHOULD BE NOTED THAT DOPPLER WIND DISPLAYS FROM
 THE BROWNSVILLE WSR-88D HAVE RECENTLY SHOWN A WELL-DEFINED
 MESOCYCLONE IN A STRONG CONVECTIVE CELL WELL TO THE SOUTHWEST OF
 THE CENTER AND THE PRIMARY CONVECTION.
  
 THE INITIAL MOTION IS 300/14.  DEEP-LAYER RIDGING OVER THE
 SOUTHEASTERN UNITED STATES SHOULD STEER DON GENERALLY
 WEST-NORTHWESTWARD UNTIL DISSIPATION.  THE FORECAST TRACK CALLS FOR
 THE SYSTEM TO MAKE LANDFALL BETWEEN BROWNSVILLE AND CORPUS CHRISTI
 IN THE NEXT 12 HR...FOLLOWED BY A MOTION ACROSS SOUTH TEXAS INTO
 NORTHEASTERN MEXICO.  THIS FORECAST TRACK IS AN UPDATE OF THE
 PREVIOUS TRACK.
  
 EVEN THOUGH THE 12 HR FORECAST POINT SHOWS WEAKENING...THERE IS
 STILL AN OPPORTUNITY FOR DON TO STRENGTHEN A LITTLE IN THE FEW
 HOURS REMAINING BEFORE LANDFALL.  THEREAFTER...THE CYCLONE SHOULD
 STEADILY WEAKEN AS IT CROSSES SOUTHERN TEXAS...AND IT IS FORECAST
 TO DISSIPATE OVER NORTHEASTERN MEXICO BY 48 HR.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  29/2100Z 26.9N  96.2W   45 KT  50 MPH
  12H  30/0600Z 27.5N  98.0W   40 KT  45 MPH...INLAND
  24H  30/1800Z 28.2N 100.6W   30 KT  35 MPH...INLAND
  36H  31/0600Z 28.8N 103.3W   20 KT  25 MPH...POST-TROP/REMNT LOW
  48H  31/1800Z...DISSIPATED
  
 $$
 FORECASTER BEVEN
  
 

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