MESOSCALE DISCUSSION 0711
   NWS STORM PREDICTION CENTER NORMAN OK
   0746 PM CDT SUN MAY 19 2013
   
   AREAS AFFECTED...CNTRL AND SRN WI INTO NRN IL
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 200046Z - 200145Z
   
   PROBABILITY OF WATCH ISSUANCE...80 PERCENT
   
   SUMMARY...AN INCREASING SEVERE WEATHER THREAT IS ANTICIPATED TO THE
   EAST OF TORNADO WATCHES 180 AND 183 LATE THIS EVENING INTO TONIGHT. 
   THE PRIMARY HAZARDS WILL BE DAMAGING WINDS AND HAIL...THOUGH A
   TORNADO OR TWO WILL BE POSSIBLE  A NEW WATCH WILL LIKELY BE REQUIRED
   WITHIN THE HOUR.
   
   DISCUSSION...THE 00Z DVN AND ILX SOUNDINGS SHOWED THAT THE LOCAL
   ENVIRONMENT REMAINS MODERATELY UNSTABLE THIS EVENING OWING TO STEEP
   LOW TO MIDLEVEL LAPSE RATES AND A MOIST PBL WHERE LOWEST 100-MB
   MEAN-MIXING RATIOS OF AROUND 13.5 G/KG WERE OBSERVED.  THOUGH SFC
   TEMPERATURES WILL START TO COOL...THE MOIST ENVIRONMENT COUPLED WITH
   THE ABSENCE OF ANY APPRECIABLE CAP SHOULD MAINTAIN MODERATE
   INSTABILITY INTO THE OVERNIGHT HOURS.  AS SUCH...EXPECT ONGOING
   BOWING TSTM COMPLEX OVER NWRN IL TO PERSIST...WITH ADDITIONAL STORMS
   DEVELOPING ACROSS DISCUSSION AREA WITHIN THE EXIT REGION OF A 40-50
   KT NOCTURNAL LOW-LEVEL WIND MAXIMUM WHERE WAA AND ISENTROPIC ASCENT
   WILL BE ENHANCED.  GIVEN A STEADY STRENGTHENING TO THE MID AND
   UPPER-TROPOSPHERIC FLOW FIELD...THE ENVIRONMENT WILL BE SUPPORTIVE
   OF EMBEDDED SUPERCELL AND BOWING STRUCTURES CAPABLE DAMAGING
   WINDS...HAIL...AND PERHAPS A TORNADO OR TWO.
   
   ..MEAD/CORFIDI.. 05/20/2013
   
   
   ATTN...WFO...GRB...LOT...ILX...MKX...DVN...ARX...
   
   LAT...LON   41209149 42899142 44019123 44449049 44448946 44108892
               43218874 41818885 41208885 40818957 40889068 41209149