ACUS11 KWNS 040149

SWOMCD

SPC MCD 040149 

ILZ000-MOZ000-040345-



Mesoscale Discussion 0637

NWS Storm Prediction Center Norman OK

0849 PM CDT Sun May 03 2026



Areas affected...portions of western and central Missouri into

Illinois



Concerning...Severe potential...Watch unlikely 



Valid 040149Z - 040345Z



Probability of Watch Issuance...20 percent



SUMMARY...Isolated to scattered high-based storms are expected to

develop this evening across parts of MO and IL. Very steep mid-level

lapse rates and moderate vertical shear could promote a few strong

to severe storms with hail and damaging gusts. A WW is unlikely.



DISCUSSION...As of 0145 UTC, regional WV imagery showed mid-level

ascent associated with an upper-level shortwave trough that was

observed moving out of the northern Plains/Rockies into parts of the

central US near a slow-moving cold front. As mid-level ascent

continues eastward, it will overspread a warm and modestly moist air

mass along and south of the front. Temperatures in the 70s with

dewpoints in the 40s and 50s amid mid-level lapse rates of 8.5-9

C/km are supporting around 1000 J/kg of MUCAPE (TOP RAOB). Strong

mid-level flow associated with the trough is also in place with

deep-layer shear of 40-50 kt.



Night time microphysics and IR imagery showed deepening ACCAS across

north-central MO and west-central IL associated with the cold front

and increased 850 mb low-level jet. Observational trends and CAM

guidance shows initially isolated high-based thunderstorm

development will likely increase in coverage this evening. Despite

limited buoyancy, the very steep lapse rates and strong vertical

shear may promote some organized supercell structures capable of

hail or damaging gusts.



Given the limited instability and more isolated nature of the severe

risk, a WW appears unlikely this evening. However convective trends

will be monitored.



..Lyons/Hart.. 05/04/2026



...Please see www.spc.noaa.gov for graphic product...



ATTN...WFO...PAH...ILX...LSX...DVN...SGF...EAX...



LAT...LON   38069196 38169303 38759402 39209411 39819384 40259236

            40399100 40208988 39938866 39308793 38788811 38398844

            38088900 38058977 38009074 38069196 



MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH

MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN