ZCZC SPCSWOMCD ALL ACUS11 KWNS 242055 SPC MCD 242055 KSZ000-NEZ000-COZ000-242300- Mesoscale Discussion 1846 NWS Storm Prediction Center Norman OK 0355 PM CDT Sat Aug 24 2019 Areas affected...portions of southwest and south-central Nebraska...central and northwest Kansas and east-central Colorado Concerning...Severe potential...Watch likely Valid 242055Z - 242300Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorms are expected to develop and increase in intensity after 4 to 5 pm CDT with large hail and damaging winds likely, and a tornado or two possible. Trends are being monitored and a watch is likely prior to 6 pm CDT/23Z. DISCUSSION...A gradually-deepening cumulus field was noted on visible satellite imagery across western portions of the KS/NE border at 2045Z. This area is on the southern periphery of a mid-level convectively-enhanced vortex, and in advance of a compact upstream impulse over northeast CO/NE Panhandle. Low-level moisture advection beneath steepening mid-level lapse rates have contributed to MLCAPE of 1500-2000 J/kg, and with additional diurnal heating some further increase in surface-based instability is likely. Mid-level northwesterly flow should increase slightly through this evening, resulting in effective shear averaging 35-45 kts. Thunderstorms are expected to develop over northern/western portions of the discussion area over the next few hours in the presence of negligible CINH and weakly confluent low-level flow. Initial mode will include supercells, with large hail, possibly significant, and damaging winds the primary threats. Notable low-level veering/curved hodographs in RAP forecast soundings, primarily across the KS portion of the discussion area, suggests some potential for low-level rotation and perhaps one or two tornadoes with more discrete storms in the first couple of hours after initiation. With time, upscale growth is anticipated as a cold pool organizes and the convective complex moves southeast this evening aided by modestly increasing low-level warm advection. Damaging winds should become the dominant threat, with large hail remaining possible with the strongest updrafts. Trends are being monitored and a watch is likely prior to 23Z. ..Bunting/Thompson.. 08/24/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ICT...GID...LBF...DDC...GLD... LAT...LON 40270164 40610078 40710029 40679983 40339925 39989870 39369837 38839833 38379842 37779894 37690023 38740226 39140235 39740226 40270164 NNNN