ACUS11 KWNS 191402 SWOMCD SPC MCD 191401 NEZ000-191600- Mesoscale Discussion 2038 NWS Storm Prediction Center Norman OK 0901 AM CDT Wed Aug 19 2026 Areas affected...parts of central and eastern Nebraska Concerning...Severe potential...Watch possible Valid 191401Z - 191600Z Probability of Watch Issuance...40 percent SUMMARY...An isolated supercell structure, perhaps with some upscale growth into a small organizing cluster, may be maintained at least into the 11 AM-1 PM CDT time frame, posing a continuing risk for large hail and locally strong to severe gusts while moving south-southeastward. It is not yet certain that this will require a severe weather watch, but trends are being monitored for this possibility. DISCUSSION...Downstream of a low amplitude short wave trough, digging within broader cyclonic northwesterly mid-level flow, at least a localized area of stronger forcing for ascent (largely associated with warm advection centered near/below the 700 mb level) is maintaining isolated vigorous convection now propagating slowly southeastward to the west and southwest of O'Neill. Strong shear within the convective layer is contributing to a sustained supercell structure, which still appears rooted above a relatively cool/stable near surface layer. Based on forecast soundings, convection appears based around 850 mb, where a narrow corridor of higher moisture content may be supporting updraft inflow of air characterized by most unstable CAPE on the order of 1500-2000 J/kg. It appears that this could be maintained at least into the 17-18Z time frame, as the stronger forcing for ascent develops south-southeastward toward the Columbus and Grand Island vicinities. ..Kerr/Smith.. 08/19/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OAX...GID...LBF... LAT...LON 42249883 42399849 41939743 41489698 40939724 41179803 41779905 42059923 42249883 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN