ZCZC SPCSWOMCD ALL ACUS11 KWNS 221728 SPC MCD 221728 SDZ000-NDZ000-221930- MESOSCALE DISCUSSION 1357 NWS STORM PREDICTION CENTER NORMAN OK 1228 PM CDT FRI JUL 22 2016 AREAS AFFECTED...PORTIONS OF SRN ND...NRN SD CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 221728Z - 221930Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...THE AREA IS BEING MONITORED FOR INCREASING SVR-TSTM POTENTIAL EARLY THIS AFTERNOON. WHILE NOT IMMEDIATELY LIKELY...IT IS POSSIBLE THAT WW ISSUANCE MAY BECOME NECESSARY DURING THE NEXT COUPLE OF HOURS. LATER THIS AFTERNOON...WW PROBABILITIES MAY INCREASE. DISCUSSION...WATER-VAPOR LOOPS INDICATE A SUBTLE...LOW-AMPLITUDE... MID-LEVEL SPEED MAX CRESTING THE N-S MID-LEVEL RIDGE POSITIONED OVER THE GREAT PLAINS. WITH POCKETS OF INSOLATION OCCURRING AMIDST THE VERY MOIST BOUNDARY LAYER IN ADVANCE OF THE SPEED MAX -- E.G. SFC DEWPOINTS IN THE LOWER/MIDDLE 70S -- MLCINH IS ERODING. MEANWHILE...THERE HAS BEEN AN INCREASE IN CONVECTIVE COVERAGE/INTENSITY ACROSS PORTIONS OF FAR S-CNTRL ND. MLCAPE DOWNSTREAM OF THIS ACTIVITY HAS INCREASED TO AROUND 2500-5000 J/KG...AND WILL PROMOTE THE POTENTIAL FOR ROBUST CONVECTION -- ESPECIALLY IF IT WERE TO BECOME SFC-BASED. HOWEVER...GIVEN THE RELATIVELY EARLY CONVECTIVE DEVELOPMENT WITHIN THE DIURNAL HEATING CYCLE...AND GIVEN THE SUBTLE CHARACTER OF THE MECHANISMS FAVORING LARGER-SCALE ASCENT...THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE SVR POTENTIAL DURING THE NEXT FEW HOURS. REGARDLESS...THE AFOREMENTIONED BUOYANCY COMBINED WITH 35-45 KT OF EFFECTIVE SHEAR SUGGESTS THAT AT LEAST ISOLATED SVR HAIL/WIND WILL BE POSSIBLE...AS CONVECTION POTENTIALLY TRANSITIONS FROM INGESTING ELEVATED INFLOW TO SFC-BASED INFLOW. IF CONVECTIVE UPSCALE GROWTH WERE TO YIELD A MORE SVR WIDESPREAD RISK -- PERHAPS EMANATING FROM A MORE PROMINENT TSTM/SUPERCELL CLUSTER AND/OR MCS -- WW ISSUANCE MAY NEED TO BE CONSIDERED IN THE NEXT COUPLE OF HOURS. LATER THIS AFTERNOON...WITH ADDITIONAL SFC HEATING/DESTABILIZATION...WW PROBABILITIES MAY BE INCREASING. ..COHEN/WEISS.. 07/22/2016 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FGF...ABR...BIS... LAT...LON 46479930 46399800 45879707 45269697 44979731 44949886 45459996 46030007 46479930 NNNN