MESOSCALE DISCUSSION 0165
   NWS STORM PREDICTION CENTER NORMAN OK
   0105 AM CST MON FEB 28 2011
   
   AREAS AFFECTED...NERN AR/WRN TN N/NEWD TO WRN KY AND FAR SRN IND
   
   CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 
   
   VALID 280705Z - 280730Z
   
   A NEW TORNADO WATCH WILL BE COORDINATED SOON FOR NERN AR...WRN TN
   N/NEWD TO WRN KY AND FAR SRN IND.
   
   A STRONG SWLY LLJ EXTENDING FROM THE LOWER MS TO LOWER OH VALLEYS IS
   MAINTAINING MOIST...MODERATELY UNSTABLE AIR MASS IN ADVANCE OF THE
   QLCS EXTENDING FROM THE SRN HALF OF IL TO NRN/WRN AR.  REGIONAL
   RADAR IMAGERY SHOWED TWO FAST MOVING BOWS...1. OVER SERN IL AND 2.
   OVER SERN MO WITH BOTH FEATURES TRACKING EWD AT 55-60 KT.  GIVEN
   THESE FAST FORWARD SPEEDS AND DOWNSTREAM DESTABILIZING AIR
   MASS...THESE BOWS WILL LIKELY EXIT WW 25 AND SRN EXTENT OF WW 27 BY
   09Z AND 08Z RESPECTIVELY.
   
   HEIGHT FALLS...ATTENDANT TO A PAIR OF PROGRESSIVE SHORTWAVE
   TROUGHS...1. OVER IL/IND AND 2. MOVING EWD ACROSS OK...WILL CONTINUE
   TO SPREAD EWD ATOP THE MOIST/UNSTABLE WARM SECTOR AND SUSTAIN THE
   ONGOING QLCS AS IT ADVANCES EWD OVERNIGHT.
   
   FARTHER S...SPECIAL 06Z SOUNDING AT LZK INDICATED A STRENGTHENING
   CAP AROUND 850 MB SINCE 03Z.  ALTHOUGH THIS CAP MAY LIMIT SUSTAINED
   UPDRAFTS/OVERALL CONVECTIVE COVERAGE...FURTHER MOISTENING OF THE
   DOWNSTREAM AIR MASS MAY SUPPORT EFFECTIVE INFLOW PARCELS THAT HAVE
   THE POTENTIAL TO REMAIN SURFACE BASED.
   
   ..PETERS.. 02/28/2011
   
   
   ATTN...WFO...LMK...OHX...PAH...MEG...LZK...
   
   LAT...LON   35259137 36629059 37908796 38638621 38618546 36738679
               35198843 35078923 35069102 35259137