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Tropical Storm DON (Text)

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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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