ACUS11 KWNS 172230 SWOMCD SPC MCD 172229 NEZ000-172330- Mesoscale Discussion 2016 NWS Storm Prediction Center Norman OK 0529 PM CDT Mon Aug 17 2026 Areas affected...portions of western into central Nebraska Concerning...Severe potential...Watch likely Valid 172229Z - 172330Z Probability of Watch Issuance...80 percent SUMMARY...The risk for severe hail and wind is increasing across portions of western and central Nebraska. A WW issuance will be issued soon. DISCUSSION...A mature supercell is approaching NE from extreme southwestern SD, with additional storms developing along the higher terrain along the NE/CO border. The storms in far northwestern NE are traversing a diffuse baroclinic boundary, where relatively richer moisture (i.e. mid 60s F surface dewpoints) is in place. 22Z mesoanalysis also depicts 7.5-8 C/km mid-level lapse rates overspreading this moisture, yielding 2500+ J/kg MLCAPE. Furthermore, a 500 mb mid-level impulse is glancing the region to the north, encouraging modest upper support and 45 kts of effective bulk shear. The current thinking is that supercell development may continue across western and central NE this evening. Storms closer to the NE/CO border are overspreading a drier, mixed boundary layer, casting some uncertainty to their longevity given weaker forcing farther south. However, the storms traversing the aforementioned boundary/richer moisture will have the best chance at maintaining intensity and producing severe gusts as well as large hail (a stone or two of which could exceed 2 inches in diameter). A Severe Thunderstorm Watch is likely given increasing storm coverage and intensity. ..Squitieri/Gleason.. 08/17/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...CYS... LAT...LON 42890403 42910176 42580009 42159926 41429916 41199935 41039990 41070124 41040305 41260363 42890403 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN