Good afternoon everyone! We are still tracking the threat for strong to severe thunderstorms stretching from far southern MN through central and eastern IA into northern MO. A more isolated strong storm risk remains across southern MO, though forcing remains very questionable at this time. Greater forcing exists north of there, especially in southeast IA and northeast MO. Shown below is an updated Severe Storm Outlook for the region containing the main timeframe and threats.
While a Severe Thunderstorm Watch remains unlikely to be issued across southern MN and northern IA this evening, a few of the scattered storms in the area may become strong to severe with marginal hail being the main threat.
With just a few hours of lead time remaining, the models are still struggling to grasp the evolution of these storms this evening into tonight. With energy in the area, a warm front lifting north into the region and a strengthening low-level jet, I suspect the NAM3km model (simulated radar shown below through 1pm CDT Saturday) has the best handle for the storms this evening and tonight. Scattered storms wrapping around the low pressure system in MN and northern IA will slowly lift eastward through central/southern MN and northern IA through the evening and early overnight hours before gradually fading as the storm system exits the state. An isolated shower or two may remain into the late overnight hours. Further south along the warm front, a broken line of strong storms is expected to develop in southeastern IA after 6pm CDT this evening before pushing along the temperature gradient southeastward that was left behind from this morning’s convection and the warm front to the west. Northern MO will work in this broken line of storms shortly after initiation with eastern MO likely receiving these storms late this evening into the early overnight hours. The severe weather threat will diminish as the night progresses. By 7am CDT Saturday morning, the remnants of these storms will be working into southern MO, though they will be more isolated in nature at this point. It is important to keep reiterating the uncertainty with this event as other high-resolution model guidance suggests a majority of northern and eastern MO miss out on these storms overnight. I find this solution to be less likely, however.
Here’s a look at total rainfall through 10am CDT Saturday: Model guidance remains all over the place regarding these storms and their subsequent rainfall. Where it storms, which is favored most in southeast IA into northeast/east-central MO, a quick 0.5-1″ of rain is likely with locally higher amounts possible in the heaviest storms. The NAM3km’s western extent of these storms is questionable and likely overdoing rainfall amounts in central MO.
Most of MN, IA, and MO will stay dry late tomorrow morning through the evening hours. A new disturbance lifting into the Northern Plains will be a caveat to this as energy brought with it will provide shower and storm risks, possibly strong, to northwest MN Saturday afternoon and eventually the rest of the state heading into the late evening and overnight hours. Localized gusty winds and small hail are possible with these storms. It appears only isolated rain chances appear likely at this time in IA and MO, especially Saturday night into Sunday morning. Simulated radar from 1pm CDT Saturday through 1am CDT Sunday:
If you have any questions do not hesitate to reach out! Have a great evening!