Additional severe weather is possible today as the Storm Prediction Center has posted two elevated risks of severe weather over Iowa. The first risk is across northwest and north central Iowa. Storms are expected to move into that area late tonight and pose a threat for large hail, damaging winds, and a tornado. There’s a lot of uncertainties with this with the primary one revolving around a very strong cap that will be in place for most of the afternoon. This could hinder storm initiation in the Northern Plains and change the forecast dramatically.

Strong shear and moderate instability will be plenty enough to get storms going initially as discrete supercells (and have best tornado threat with it.) However, most of this activity should remain in the Plains. The worry about our neck of the woods is what will happen as a strong low level jet increases overnight. There’s multiple possibilities about what could happen with this, however the current expectation is that it will cause cells to grow into an upscale mesoscale convective system and last long into the night diurnally.

The second risk are across southern Iowa is moreso for our standard summer time flare up thunderstorms that may produce some quarter size hail and damaging winds. There is no real organized severe weather threat here. However, as showers develop, there is some environment for severe weather, hence the reason for the elevated risk of severe weather.

Additional severe weather is possible on Monday, primarily across Wisconsin and Michigan, where an enhanced risk of severe weather exists. This does have the potential to be significant for these areas, however uncertainties is preventing categorical upgrades. A continuing full force upper-level trough will move eastward Monday with a very strong mid-level jet in addition to that. A low pressure center will move into the Great Lakes region with an extending cold front, which will likely serve as the focal point for storms on Monday. Very muggy dew points in the 70s with warm temperatures will create a classic severe weather “feeling” type of day in the region. This will lead to moderate-to-strong instability. Combined with the upper-level features interacting with the mid-level jet, organized shear – Monday could be a potentially significant day in this area.

The uncertainties involved with this day is how the morning storms will interact with things later in the day. The current expectation is that the previous days MCS should be out of the way by early afternoon and allow for development to occur in southeastern Minnesota and norhteastern Iowa before intensifying as moving east. High instability and very strong shear in some places will lead to a large hail, damaging wind, and tornado threat. The tornado threat would be enhanced with strong, long track tornadoes possible with the high-end shear. Some other solutions also have this as a high-end severe MCS that would produce damaging winds.

Either way, it would be a good idea to keep an eye on the weather over the next few days. Stay tuned to the Iowa Weather Network for the latest information!