ZCZC SPCSWOMCD ALL ACUS11 KWNS 131752 SPC MCD 131752 ILZ000-IAZ000-MOZ000-KSZ000-NEZ000-131945- MESOSCALE DISCUSSION 0623 NWS STORM PREDICTION CENTER NORMAN OK 1252 PM CDT FRI MAY 13 2016 AREAS AFFECTED...PORTIONS OF ERN KS...NRN MO...SRN IA...FAR WRN IL CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 131752Z - 131945Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...SEVERE THUNDERSTORMS WILL DEVELOP AHEAD OF A COLD FRONT BY MID-AFTERNOON FROM SOUTHERN IA THROUGH EASTERN KS. DAMAGING WIND AND HAIL WILL BE POSSIBLE WITH THESE STORMS. A SEVERE THUNDERSTORM WATCH WILL LIKELY BE NEEDED AROUND 19Z. DISCUSSION...ELEVATED THUNDERSTORMS DEVELOPED THIS MORNING IN THE VICINITY OF A PREFRONTAL TROUGH AND ENHANCED DEEP LAYER NORTHWESTERLY FLOW. THIS EARLY CONVECTION MAY CONTINUE TO PRODUCE MARGINALLY SEVERE HAIL AS IT TRACKS EASTWARD ACROSS PARTS OF SRN IA AND NE KS. OTHERWISE...A MORE SUBSTANTIAL/WIDESPREAD SEVERE THREAT WILL DEVELOP THIS AFTERNOON AHEAD OF THE SOUTHEASTWARD SURGING COLD FRONT FROM SRN IA INTO CNTRL/ERN KS. SURFACE DEWPOINTS CURRENTLY RANGE FROM THE UPPER 40S TO LOW 50S...BUT ARE NOT EXPECTED TO INCREASE MUCH MORE. DESPITE POOR BOUNDARY LAYER MOISTURE...STEEP MIDLEVEL LAPSE RATES GREATER THAN 7.0 DEG C/KM AND WEAK TO MODERATE INSTABILITY WILL OVERSPREAD THE MCD AREA THIS AFTERNOON. AS OF 18Z...VISIBLE SATELLITE IMAGERY SHOWED CU FIELD BUBBLING BENEATH RAPIDLY ERODING CAP ACROSS CNTRL INTO NE KS AHEAD OF THE SURFACE BOUNDARY AND MORE WIDESPREAD DEVELOPMENT IS EXPECTED WITHIN THE NEXT COUPLE OF HOURS. VERTICAL WIND PROFILES WILL REMAIN MAINLY UNIDIRECTIONAL WITH SOME BACKING FLOW NEAR THE SURFACE. A FEW SUPERCELL STRUCTURES WILL BE POSSIBLE BUT A QUICK PROGRESSION TOWARD BOWING LINE SEGMENTS IS EXPECTED. GIVEN THE LARGE TEMPERATURE-DEWPOINT SPREAD /DCAPE AROUND 1000-1500 J PER KG/ RESULTING IN ENHANCEMENT OF DOWNDRAFTS AND FAVORING COLD POOL DEVELOPMENT...DAMAGING WIND WILL BE THE MAIN CONCERN. HOWEVER...THE PRESENCE OF STEEP LAPSE RATES COULD ALSO ALLOW FOR SOME LARGE HAIL...ESPECIALLY EARLY IN STORM DEVELOPMENT OR WITH ANY CELLS THAT REMAIN MORE ISOLATED. THE THREAT WILL SPREAD EASTWARD INTO NRN MO/WRN IL LATER THIS AFTERNOON AS THE MAIN UPPER IMPULSE SHIFTS SOUTHWARD THROUGH THE UPPER MS VALLEY. A WATCH WILL LIKELY BE NEEDED FOR PORTIONS OF THE MCD AREA AROUND 19Z. ..LEITMAN/GOSS.. 05/13/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ILX...LSX...DVN...DMX...EAX...OAX...TOP...ICT... DDC... LAT...LON 40729492 41319278 41329171 41189084 40799052 40399066 39699133 39109253 38449402 37899546 37709615 37609712 37629731 37709797 38099855 38349868 38529860 38899835 39279784 40109620 40729492 NNNN