MESOSCALE DISCUSSION 0580
   NWS STORM PREDICTION CENTER NORMAN OK
   0734 PM CDT MON APR 25 2011
   
   AREAS AFFECTED...PORTIONS AR...EXTREME SRN IL...NE TX...EXTREME SWRN
   INDIANA...NWRN MS...SERN MO...NRN LA...WRN KY...WRN TN.
   
   CONCERNING...TORNADO WATCH 205...206...
   
   VALID 260034Z - 260230Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 205...206...CONTINUES.
   
   THREAT FOR SIGNIFICANT TORNADOES AND DAMAGING WIND CONTINUES ACROSS
   WWS ALONG AND E OF PRIMARY CONVECTIVE COMPLEX THAT EXTENDS FROM NEAR
   CGI THROUGH LIT-TXK CORRIDOR AND JUST N TYR AS OF 00Z.  ENVIRONMENT
   WILL BECOME MORE FAVORABLE OVER AR/LA BORDER REGION EWD TO DELTA
   REGION...FROM WRN TN SWD TO NEAR LA BORDER THROUGH REMAINDER
   EVENING.
   
   AS OF 00Z...TORNADIC SUPERCELLS WITH HISTORY OF DAMAGE OVER HOT
   SPRINGS AREA...INCLUDING APPARENT DEBRIS SIGNATURE OVER SRN CONWAY
   COUNTY...ARE PROCEEDING NEWD ACROSS CENTRAL AR...FOLLOWED BY
   INCREASINGLY WELL-ORGANIZED BOW ECHO MOVING NEWD ABOUT 60 KT TOWARD
   LIT METRO AND CAPABLE OF SIGNIFICANT-SVR WIND.  SUPERCELLS WILL BE
   MOVING NEWD ABOUT 40 KT...REMAINING AHEAD OF BOW FOR ANOTHER 1-2
   HOURS.  ALL THIS ACTIVITY WILL REMAIN WITHIN BAROCLINIC GRADIENT
   FROM CENTRAL-NERN AR AND WILL REMAIN CAPABLE OF SIGNIFICANT
   TORNADOES...WITH PROXIMITY 00Z LZK RAOB SHOWING 0-1 KM SRH APCHG 400
   J/KG.  BLEND OF SUPERCELL AND BOW MODES IS POSSIBLE FARTHER S IN
   CONVECTIVE COMPLEX...AS ACTIVITY MOVES FROM NE TX AND SWRN AR ACROSS
   REMAINDER OF ARKLATEX REGION AND OVER SRN AR AND EXTREME NRN LA. 
   SERN MO/SRN IL ACTIVITY WILL MOVE INTO PROGRESSIVELY MORE STABLE
   AIR...BUT REMAINS CAPABLE OD DAMAGING WIND.
   
   STRONG PRESSURE FALLS ARE ANALYZED OVER SERN AR...MAINTAINING BACKED
   SFC WINDS WITH 300-500 J/KG OF 0-1 KM SRH.  AS LLJ STRENGTHENS
   DURING NEXT 2-3 HOURS...LOW-LEVEL HODOGRAPHS SHOULD ENLARGE FURTHER
   ACROSS SRN AR...NRN LA EWD TOWARD NWRN MS AND WRN TN. RELATED WAA
   AND MOISTURE TRANSPORT MAY DISPERSE RELATIVE DRY POCKETS NOW
   ANALYZED AT SFC OVER PORTIONS NRN LA AND WRN MS...LEADING TO MORE
   UNIFORM FIELD OF MLCAPE RANGING FROM 500 J/KG OVER ERN AR TO 2000
   J/KG IN NRN LA...AMIDST 60-70 KT EFFECTIVE SHEAR MAGNITUDES.
   
   ..EDWARDS.. 04/26/2011
   
   
   ATTN...WFO...OHX...PAH...MEG...JAN...LSX...LZK...SHV...FWD...
   
   LAT...LON   32999541 33519381 34689281 35439224 35779089 36859029
               38028972 38138772 37588747 33978933 33119109 32469274
               32999541