MESOSCALE DISCUSSION 1076
   NWS STORM PREDICTION CENTER NORMAN OK
   0130 PM CDT FRI JUN 12 2009
   
   AREAS AFFECTED...AR
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 388...
   
   VALID 121830Z - 122000Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 388
   CONTINUES.
   
   THE POTENTIAL FOR WIDESPREAD DAMAGING WINDS AND LARGE HAIL WILL
   CONTINUE THIS AFTERNOON WITH BOW ECHO.
   
   DERECHO-PRODUCING BOW ECHO CONTINUES 285-290/40-45 KT...AND AS OF
   1810Z...THE LEADING EDGE OF SYSTEM WAS LOCATED FROM CARROLL AND
   MADISON COUNTIES INTO LOGAN AND SCOTT COUNTIES AR.  OVER THE PAST
   HOUR...A NEW PRONOUNCED REAR INFLOW NOTCH HAS BECOME ESTABLISHED
   FROM CRAWFORD INTO FRANKLIN COUNTIES WITH AN ASSOCIATED DOWNSTREAM 
   BOWING OF LEADING CONVECTIVE LINE WHICH HAS ACCELERATED TO NEAR 50
   KT.  LATEST VWP DATA FROM FT. SMITH APPEARS TO HAVE SAMPLED THE REAR
   INFLOW JET WITH 50-60 KT WINDS BETWEEN 1-2 KG AGL.
   
   DOWNSTREAM AIR MASS OVER CNTRL AR HAS WARMED THROUGH THE 80S.  WHEN
   COUPLED WITH DEWPOINTS IN THE LOW/MID 70S AND STEEP MIDLEVEL LAPSE
   RATES...ENVIRONMENT IS STRONGLY UNSTABLE WITH MLCAPE OF 3000-4000
   J/KG.  THUS...EXPECT BOW ECHO TO CONTINUE SEWD WITH THE POTENTIAL
   FOR SIGNIFICANT WIND DAMAGE REACHING LITTLE ROCK AROUND 20Z.
   
   ..MEAD.. 06/12/2009
   
   
   ATTN...WFO...MEG...JAN...LZK...SGF...SHV...TSA...
   
   LAT...LON   34569507 35329536 36729460 36989376 36259133 35738978
               34348968 33299064 33099191 33469336 33979432 34569507