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