ZCZC SPCSWOMCD ALL
ACUS11 KWNS 281836 
SPC MCD 281836 
ILZ000-MOZ000-IAZ000-282030-

MESOSCALE DISCUSSION 1219
NWS STORM PREDICTION CENTER NORMAN OK
0136 PM CDT SUN JUN 28 2015

AREAS AFFECTED...MUCH OF CNTRL INTO ERN MO...WRN IL...

CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY 

VALID 281836Z - 282030Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...A FEW SUPERCELLS ARE EXPECTED TO DEVELOP IN THE 20-21Z
TIME FRAME FROM CNTRL MO INTO WRN IL. TORNADOES AND LARGE HAIL ARE
EXPECTED. THE ST. LOUIS AREA IS IN THE HIGHEST THREAT CORRIDOR.

DISCUSSION...A WELL-DEFINED SHORTWAVE TROUGH CONTINUES TO MOVE SWD
ACROSS THE MID MS VALLEY WITH SURFACE LOW OVER CNTRL IA AT 18Z.
SURFACE OBSERVATIONS INDICATE A WIND SHIFT EXTENDING SWWD FROM THE
LOW...WITH AN EFFECTIVE WARM FRONT/OUTFLOW NEAR THE MS RIVER IN
ASSOCIATION WITH AN ONGOING AREA OF SHOWERS AND STORMS.

VISIBLE IMAGERY SHOWS STRONG HEATING AND MIXING HAS COMMENCED
UPSTREAM OF THE AREA...WITH A PLUME OF STEEP LOW-LEVEL LAPSE RATES
FROM KS INTO WRN MO. MODIFIED FORECAST SOUNDINGS INDICATE LITTLE CIN
REMAINING AS TEMPERATURES RISE INTO THE MID 80S F. 

AS THE SURFACE LOW TRAVELS SEWD...LOW-LEVEL WINDS JUST AHEAD OF IT
WILL REMAIN BACKED...WITH A ZONE OF ENHANCED LOW-LEVEL SHEAR ALONG
THE RESIDUAL OUTFLOW BOUNDARY. THE STRONG FORCING FOR ASCENT COUPLED
WITH FAVORABLY VEERING WIND SHEAR PROFILES WITH HEIGHT WILL STRONGLY
FAVOR SUPERCELLS...AND A FEW TORNADOES ARE ANTICIPATED.

ACTIVITY IS EXPECTED TO INITIATE NEAR THE OUTFLOW BOUNDARY...WITH
STORMS MATURING AS THEY TRAVEL SEWD. OTHER CELLS WILL FORM LATER IN
THE AFTERNOON ALONG THE ADVANCING WIND SHIFT WITH A HAIL AND TORNADO
THREAT.

..JEWELL/HART.. 06/28/2015

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...ILX...LSX...DVN...SGF...DMX...EAX...

LAT...LON   38438974 38269045 38249236 38469294 38739314 39409284
            39949286 40649258 40899188 40659094 40089047 39268982
            38698959 38438974 

NNNN