textproduct: Kansas City/Pleasant Hill

KEY MESSAGES

- Severe Storms Friday Late Afternoon Through Evening

- Additional Flooding Possible With Heavy Rainfall

- Cooler Over the Weekend, Start of Next Week

DISCUSSION

Issued at 1137 PM CDT Thu Apr 2 2026

Surface low and associated mid-level short-wave trough has moved into the Great Lakes Region, and the trailing cold front has pushed southeastward toward the Interstate 44 corridor. Low-level stratus and lingering moisture primarily across Iowa and northern Missouri will result in low stratus and fog potential mainly across our northern zones this evening. The front should stay outside of the forecast for most of the evening. Elevated convection may develop along the front closer to Interstate 44 as the low-level jet intensifies this evening. This activity is expected to miss our southern and southeastern zones.

The quiet weather conditions will be short-lived, a stronger mid- level trough and strong vorticity maxima, currently working across the Intermountain West eventually ejects out of the Front Range and lifts into the Plains. Stronger dCVA over the past 18-24 hours developing another strong surface cyclone over the Front Range and High Plains, and this will begin to push eastward. Surface pressure falls expand eastward mainly along the stalled cold front by Friday morning. Low-level flow turns southerly and will push the boundary back northward as a warm front. Dewpoints have not drastically decreased on the backside of this boundary, and continued moisture transport throughout Friday will foster dewpoint temperatures likely into the mid and upper 60s in the warm sector of this system. Given the setup, would expect strong isentropic ascent, leading to increasing cloud cover, showers, and if any kind of mid-level perturbation moves through, perhaps elevated convection. The 00z HRRR hints at isolated to scattered elevated shower/storm activity on the cool side of the effective warm front starting late morning and continuing through the early afternoon. While some small hail could be possible with this, most of this activity should be weak. Heading into the afternoon, most CAMs are in decent agreement on the warm front surging into central Iowa, with the tighter moisture gradient positioned in southern Iowa. The WAA and theta-e transport will provide MUCAPE pushing upwards of 2500 J/kg through the afternoon. A big question for afternoon instability will be if cloud cover breaks apart at any point. Given the amount of moisture still present even on the cool side of the boundary, it may take a notable compact ridge axis or some other kind of sharp but short-lived shot of subsidence to clear things out. With the moisture content on the boundary layer and even up through about 850mb, boundary layer mixing may not be as robust throughout the warm sector if dense cloud cover remains in place. RAP and HRRR soundings so far for Friday afternoon, while higher in CAPE values, are not overly impressive with lapse rates. The other thermodynamic factor, will be the trend of mid-level lapse rates. Most model guidance depicts the H5 short-wave trough closing up, with a lot of the mid-level vorticity being wrapped around over the Central Plains, while the surface low still moves eastward. As a result, H5 cooling above the warm-sector will not be as prominent immediately above the surface warm sector as it would be if the wave remained open and negatively titled. This disconnect in kinematics is the complicating factor for Friday's forecast because it lowers confidence in storm mode evolution through the event.

Starting with the mid to late afternoon time frame, when most of the forecast area is well within the warm sector, temperatures in the mid to upper 70s and dewpoints in the mid to upper 60s. With the right combination of surface pressure falls and convergence especially near the warm front, there may be some lift for discrete activity between 19-21z, probably some where along or north of Hwy. 36. Current CAM guidance does not depict anything robust initiating on the warm side of this boundary, and a look at model soundings near the warm front show that even with lower LCLs, the level of free convection for parcels is still fairly high. In order to get anything during the afternoon, we may need some kind of mid-level vort maxima to provide that extra lift, which will be hard to come by if the H5 wave closes off. Now if the forcing is there to get an updraft, and storm motion can keep it from crossing to the cool side, the low-level shear environment is quite impressive, with 0- 1km bulk shear values upward of 40 kts and low-level SRH values pushing above 150 m^2/s^2, and the structure of the model hodographs do show strong cyclonic curvature, especially in the axis of surface pressure falls where surface winds back through the afternoon. This could help to sustain a low-level mesocyclone. However, the deep layer shear over the warm sector could be a problem. The stronger H5 height gradient and associated jet streak is shaping up to be well displaced northwest of the surface warm sector. So while raw values of 0-6km bulk shear are showing 40+ kts, most of that is occurring within the first 0-2km. Current HRRR sounding hodographs actually show backing between 3-6km, as the mid-level flow is not substantially faster than the lower-level flow. Initial cells that would move with the mean wind may actually experience some suppression. For deep convection to be fully supported by the wind shear, a left-mover would have the best kinematic support for sustaining development, but that would also be more likely to take its motion across the boundary to the cool side. Therefore, if initiation happens near the warm front in the afternoon and deviates left, will have potential to produce larger hail, perhaps above 2 inches. Limiting factor would be the lapse rates as currently progged, but just enough CAPE through the hail growth zone may still be present. The low-level SRH and hodograph shape would suggest some tornado potential with discrete convection on the warm side of the boundary as low-level mesocyclone development could be favored, especially with any rightward motion. However, unsure if the deeper layer shear would be able to sustain such an updraft for a long enough period that allow the low-level meso to persist. Any discrete convection on the warm side would also present a wind threat, especially if a supercell mode could be achieved. This afternoon development is the lower confident part of the forecast with uncertainty if things will even initiate, and then will it have what it needs to be sustained. Watching the wind profile and tracking areas of clearing will be the main mesoanalysis task through Friday morning and early afternoon.

Later into the afternoon and evening, surface cyclone moves eastward, and may deepen some but the main dCVA displaced northwest may prevent further deepening by the evening hours. Attention will then turn to the cold front and increasing convergence along it, and the potential for a triple point if the cyclone begins to occlude. This would likely develop in north-central Missouri. Deep layer shear should increase some through the evening in close proximity to the cold front, though a lot of it may be confined behind the cold front as the closed H5 low moves eastward, allowing for better mid- level flow heading into the evening (compared to the afternoon). While convergence increases, there may a brief window between 22z- 00z where a discrete updraft could take on a supercellular mode with its inflow taking advantage of the warm-sector, presenting all severe hazards. Larger hail should be supported with better lift, and perhaps better mid-level lapse rates. Mid-level shear should also be better that would not suppress updraft development in the same way that the warm front setup could earlier in the day (along with favorable storm motion toward the warm sector). Low-level SRH values will still be high and low-level hodographs could still be curved cyclonically enough to support a tornado threat with a discrete storm, especially along a triple point if surface winds can remain backed. As of right now, this corridor would probably be along or north of Hwy. 36 if a triple point develops. Along the rest of the cold front and remainder of the warm sector south of Hwy. 36, surface winds may veer, which would reduce SRH quite a bit. As the low-level jet then cranks up, most of the cold front should fill in, eventually leading to an MCS and QLCS of some kind. With decent 0- 3km bulk shear, a well organized QLCS may not be out of the question, but just depends on how rapidly the upscale growth occurs. As this develops, damaging winds become the primary threat. If a strong QLCS mode is realized, the kinematics may be there to support mesovortex generation along the leading edge of the line. This may require notable surges and rear-inflow jets to develop for this to be achieved though. Most CAMs are fairly progressive with this front, having the system past Hwy. 63 in Central Missouri between 04- 05z. We will see if this changes with subsequent model runs, especially with that mid-level wave closing off, that may delay the propagation of the cold front.

With the amount of moisture transport across the warm sector, PWATs are progged to reach around 1.75 inches along portions of the expected QLCS or MCS and with enough MUCAPE into evening, may lead to efficient rainfall rates. This system though is expected to be more progressive than the Wednesday system though, which should help to limit training storms. But, for our eastern and southeastern forecast zones that are still seeing lingering flooding, may be augmented once again even if event total QPF is no more than 2 inches. At this point, have not issued a flood watch yet, but as 06z guidance comes in, a flood watch may become necessary for the southeastern third or even two-thirds of the forecast area. River and creeks throughout central Missouri may continue to see rises as this system passes through.

After this system passes into the Great Lakes Region Saturday morning, amplified ridge over the western CONUS will provide mid- level northwesterly flow across our area through much of the weekend, providing an AVA regime and surface anticyclone development. This will keep temperatures cooler through Monday. Weak perturbation through the flow may provide some shower activity into portions of Monday and Tuesday. By the middle of next week, surface high pressure moves eastward, low-level returns southerly and should push temperatures back into the upper 60s and lower 70s.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 641 AM CDT Fri Apr 3 2026

MVFR cigs will prevail thru 05Z-06Z before cigs become VFR. Showers and thunderstorms will be poss at the terminals btn 21Z-01Z reducing vis to 4SM-5SM. Winds to begin he TAF pd will be out of the SE btn 12-18kts with gusts to 20-25kts but will become southerly aft 16Z-17Z at 15-20kts with gusts around 25kts. A cold front will move thru the TAF sites btn 00Z-01Z shifting winds to the WNW btn 10-15kts with gusts to 20kts which will diminish to 5-10kts aft 05Z-06Z.

EAX WATCHES/WARNINGS/ADVISORIES

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