Good evening everyone! A cluster of showers and storms still persist across northern MO into southwestern IA as of 4:40pm CDT. Over the course of the next few hours, we expect these storms to slowly weaken while leaving room for additional strong storm development across IA, northern MO, most of NE and northern/western KS. Some isolated strong storms have also developed in central NE.
Areas of convection persisting across portions of the area today is likely limiting some of the storm development that is expected to develop over the next few hours. Regardless, some destabilization of the atmosphere along with decent wind shear, instability and low-level moisture will all aid in strong storm development, especially across IA, this evening into tonight. The potential exists for damaging wind and large hail to accompany these storms as they push eastward. A couple isolated tornadoes cannot be ruled out given the dynamics at play. A disturbance pushing into the Western Plains this evening/tonight will also spark scattered strong storms.
Here’s a brief synopsis of what to expect heading through the remainder of the evening. Remaining areas of showers and storms across IA and MO will continue to drift eastward and weaken. Some isolated storms have developed across north-central NE and while this model does not pick up on that energy, isolated damaging winds and large hail may accompany these storms over the next several hours before convective inhibition (negating factor for storm development) increases and likely weakens this area of storms. Elsewhere, a new disturbance will lift into the Western Plains this evening while a complex of strong to severe storms is expected to fire east of there in the vicinity of eastern NE, western IA, far northeastern KS and far northwestern MO. These areas will progress eastward overnight with the eastern area likely having upscale growth in coverage.
By 7am CDT Saturday morning, a couple complexes of storms will likely be persisting across the state of IA with storm coverage still persisting across portions of northern MO and eastern NE. More isolated development is likely to hang back further southwest into northern and western KS. Here’s a look at what to expect:
Simulated radar through 7am CDT Saturday morning: Areas of showers and storms in IA and MO will continue to weaken through the evening. Replacing it will be a complex of storms that is expected to fire in the next few hours across far eastern NE, southwestern IA, northeastern KS and far northwestern MO. Upscale growth is likely into western and central IA during the late evening and overnight hours, slowly pushing eastward as well. Strong isolated storms in north-central NE will drift eastward this evening, likely fading as support decreases. The Western Plains disturbance will lift into the area over the next few hours as well, pushing east across the state of NE through the overnight hours. Heading into tomorrow morning, areas of strong storms are likely in IA, northern MO and eastern NE with isolated showers and storms across northern/western KS.
The severe weather threat for Saturday looks to shift slightly further south. We feel that portions of the “marginal” risk could be upgraded to a slight risk given the parameters. The biggest strong storm threat will come during the evening and overnight hours, however strong storms with hail and damaging winds can’t be ruled out with any storm in the region throughout the day. A couple tornadoes are also possible.
Upper-level energy will align along a almost stationary frontal boundary tomorrow afternoon and evening. With upper-air flow nearly parallel to this boundary, the storms that develop in the circled region tomorrow evening likely will train over similar areas, increasing the flood threat. This energy will lift northeastward as well during the overnight hours, bringing heavier storms to northern IA as well.
Simulated radar from 7am CDT Saturday through 7am CDT Sunday: Areas of heavy, strong storms over IA will lift eastward through the morning. Trailing energy will continue storm chances in IA, southern NE, northwest MO, and KS during the early afternoon hours before an additional round of heavy, strong storms ignite along the frontal boundary from southern IA, southern NE, northern/western KS, and northern MO after 4pm CDT Saturday. These storms will likely trail in a line through the evening and early overnight hours across these areas, increasing the concern for heavy rainfall amounts. The energy will begin to lift northward overnight, slowly migrating these rains further north with northern IA possibly being impacted. Another wave lifting into western KS overnight Saturday into Sunday will continue to bring storm chances. By Sunday morning, most convection will be confined to portions of IA and NE, but with energy remaining and a decent low-level jet persisting, I can’t rule out more coverage than what is shown across southwestern NE and western KS.
Total rainfall through 7am CDT Sunday: A swath of heavy rain is likely to setup across southern IA into portions of eastern NE and far northern MO. Widespread rainfall amounts of 1-3″ are likely, especially in southern IA with localized pockets of 3-5″ not out of the question. A corridor of heavy rain along the frontal boundary is also possible stretching from northeastern to southwestern KS. Localized 1-3″ of rain is possible in these areas. It will likely remain drier across southeastern KS into the southern half of MO.
If you have any questions do not hesitate to reach out! Have a great Labor Day Weekend!