textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

* Strong to severe storms may develop along and south of I-70 later tonight. The strongest storms can produce large hail (2 to 3.5 inches), damaging winds, and an isolated tornado is possible in the vicinity of and south/southeast of the Kansas City metro.

* Rounds of showers and thunderstorms continue through Monday morning.

* Hot and humid conditions barge in this afternoon and linger through Monday.

DISCUSSION

Issued at 217 PM CDT Sun May 31 2026

A lee shortwave combined with a highly negatively titled upper level trough ushered in a complex of showers and thunderstorms through the morning hours. These storms set up a one two punch for today starting with an incredibly saturated low layer leading to dew points in the mid 70s combined with that warm southerly advection likely pushing temperatures into the 80s results in a hot, soupy, and sticky afternoon. These preceding showers also dramatically affect the potential for showers and thunderstorms later this afternoon and evening. Ironically, these morning storms will act as the greatest uncertainty while also presenting the greatest clarity in further expectations.

Let's start with what is apparent. Water vapor satellite imagery shows a strong upper level trough across the northern Rocky Mountains. 500mb height analysis shows several shortwave perturbations progressing across the SW CONUS ejecting into the central CONUS. Surface obs and 850mb analysis show a lee trough centered across SW KS coarsely spreading warm fronts across NE KS and into western OK. The wake air of the morning convection muddies the observations as you get further east of TOP. However, water vapor imagery also shows strong southwesterly flow into the central CONUS. This warm air and moisture advection, accelerated by the kinematics of the lee surface low and a high pressure off the SE TX coast, looks to quickly destabilize the air behind these morning storms. Unfortunately, this will be felt as hot, sticky, and generally unpleasant air out there this afternoon. Temperatures reach into the 80s for most, but dew points are expected to rise into the low to mid 70s (especially south of the MO River) which pushes heat index values toward the upper 90s.

This moisture rich warm air creates a notably unstable environment through the afternoon and into the evening. A critical uncertainty for this second round of storms is where any outflow boundary from this morning's storms will develop which will likely act as the necessary nudger to get storms going. With the further than anticipated southern coverage of storms. This boundary stalled out near Pittsburg KS into south central MO. It has since retreated progressed northward with the ambient warm air advection this afternoon pushing it to near Nevada, MO at the time of writing. Lee cyclogenesis continues across western KS and OK while 500mb shortwaves simultaneously pass overhead. This is likely going to result in concentrated areas of lift that look to initiate convection along this outflow boundary or close to the center of the low across eastern KS. Once that cap is broken, storms are expected to quickly develop.

Timing and location of initiation remains uncertain. CAMs spread from isolated development starting during the late afternoon 4-6 PM likely in south central and SE KS to southern MO more rapid development around 8-10 PM closer to the I-70 corridor. Morning storms stuck around for about an hour more than anticipated which does lean more toward the later start time. In reality, convective initiation will depend on when the right ingredients come together and when there is something to spark off storms. CAM guidance suggests pretty much anytime after 3-4 PM today being ripe for initiation. Although surface obs show temperatures and dew points are not ascending as fast as anticipated (likely due to the delayed start). As the evening goes on, the environment does continue to destabilize and generally move northward toward the I-70 corridor.

Regardless of timing and location, the expectation remains that storms will start as discrete likely with some supercells presenting all severe hazards (large hail, damaging winds, and tornadoes). Storms then evolve into a large scale complex which pushes its way through the remainder of MO through the night. Once again, large hail and damaging winds remain the primary hazards; however, heavy rainfall becomes more widespread. PWAT values above 1.5 inches (especially south of the MO River) combined with robust updrafts open up the potential for heavy rainfall. Heightening this concern are the storm motion vectors with the more discrete cell vectors orienting NW to SE, but the downshear vector forming straight W to E. This increases the concern for training storms and potential flooding as this storm motion could be parallel to the boundary. When compounded upon the rainfall and runoff of the past several days, the potential for both flash and river flooding continue through the overnight into Monday morning. Some rivers may stay near to above flood stage into Tuesday depending on continued rainfall.

Monday morning paints a similar picture to this morning; however, upper level ridging follows the storms. Highly saturated air from the overnight storms helps dew points reach the low to mid 70s resulting in another sticky soupy day. Heat index values push into the 90s and approach triple digits to our south. The good news is northwest flow from a digging trough across the NE CONUS keep potential precipitation to the south given us some more time to dry out from recent rain. An embedded ridge in the flow brings relatively cooler and drier air pushing dew points back into the 50s making the mid to late week feel much more comfortable. The pattern does look to become more active again presenting returning precipitation chances toward the end of the week and into next weekend.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 612 PM CDT Sun May 31 2026

Storms are expected to impact the corridor of terminals later this evening. Isolated storm development could occur as early as 01Z or 02Z, but the higher likelihood window is between 04Z and 07Z, offset about an hour earlier to the south and an hour later to the north. Initially discrete cells are expected to congeal into a larger cluster of storms as they move east and away from the terminals. In the hours surrounding sunrise Monday, patchy fog may be able to develop with diminishing cloud cover and lightening winds, but confidence is too low to be included in the TAF at this time.

EAX WATCHES/WARNINGS/ADVISORIES

MO...None. KS...None.