286 ACUS11 KWNS 182007 SWOMCD SPC MCD 182007 OKZ000-TXZ000-182200- Mesoscale Discussion 0776 NWS Storm Prediction Center Norman OK 0307 PM CDT Mon May 18 2026 Areas affected...Western Oklahoma into Northwest Texas Concerning...Severe potential...Watch possible Valid 182007Z - 182200Z Probability of Watch Issuance...40 percent SUMMARY...Though quite uncertain, storm development along the dryline is possible late this afternoon. All severe hazards would be possible if storms can form and mature. Convective trends will be monitored for a possible watch. DISCUSSION...Observations from the West Texas Mesonet show 100+ F temperatures within the eastern Panhandle/South Plains. Cumulus along the dryline have showed some increase in agitation in southwest Oklahoma resulting from the strong dryline circulation. While the 18Z OUN sounding did show a capping inversion, a more recent TAMDAR sounding from OKC did show very modest cooling/lifting of that inversion. Those signs of larger-scale lift may be all that will be observed for the remainder of the afternoon/evening. Model guidance shows modest mid-level height rises are forecast to occur. There is low confidence in storms being able to initiate/mature. If a storm or two can form, the environment would support all hazards. Convective trends will continue to be monitored. ..Wendt/Hart.. 05/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN... LAT...LON 33879923 33699954 33749970 33939990 34159976 34759961 35729962 36189988 36379984 36419938 36169888 35219877 34259902 33879923 MOST PROBABLE PEAK TORNADO INTENSITY...120-145 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  679 ACUS11 KWNS 182029 SWOMCD SPC MCD 182029 IAZ000-MOZ000-KSZ000-NEZ000-182230- Mesoscale Discussion 0777 NWS Storm Prediction Center Norman OK 0329 PM CDT Mon May 18 2026 Areas affected...Portions of Mid-Missouri Valley Region Concerning...Severe potential...Watch likely Valid 182029Z - 182230Z Probability of Watch Issuance...80 percent SUMMARY...The threat for severe storms will increase into the evening. Tornadoes will remain possible along the Iowa/Missouri border with hail becoming the primary hazard with northward extent. One or more watches will be needed this afternoon. DISCUSSION...At least modest airmass recovery has occurred along the Iowa/Missouri border region. Dewpoints have risen into the mid 60s to low 70s F in some locations. North of the boundary, steep mid-level lapse rates are in place per the 18Z OAX sounding. As the shortwave trough moves into the area, additional storm development is likely. This is already occurring in eastern Nebraska. Furthermore, additional theta-e advection ahead of the ongoing supercells in north-central Kansas and southeast Nebraska will allow a tornado threat to persist northeast of PDS WW 222. One or more watches will be needed this afternoon. The tornado threat will be maximized south of the boundary with a transition to more of a hail threat with elevated storms to the north. ..Wendt/Hart.. 05/18/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DMX...EAX...OAX...TOP...GID... LAT...LON 40569724 41199752 41659722 41989617 41969535 41769429 41399360 40759341 40029371 39529415 39589472 39809501 40569724 MOST PROBABLE PEAK TORNADO INTENSITY...140-170 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.00-3.50 IN