Wednesday Severe Weather

A strong lee cyclone will continue to move eastward tonight and through tomorrow, situating itself near the Nebraska/South Dakota border by mid-afternoon. This low will begin to occlude with the development of a potential secondary low near the KS/NE borders tomorrow afternoon as well. As the low occludes, it will begin to move off to the northeast into central Minnesota by Thursday night. As the low slowly moves off to the east/northeast, a secondary trough may slide through the state and allow more rain, possible snow showers for Thursday night into Friday.

As for the severe weather threat, it appears the timing of the frontal passage will be too late for Iowa to see a significant severe weather threat. However, the western half of the state will still likely be in a slight risk for severe weather as the late evening and early overnight thunderstorms that move into the state will be capable of damaging winds and large hail. The tornado threat will be there tomorrow, but will likely be along and just west of the I-29 corridor including southeast South Dakota, eastern Nebraska, and points southward. These storms that develop/evolve into the state during the evening hours may be capable of a tornado or two by the forecasts at this point, however the main threats for the western half of the state will be for damaging winds and some marginally large hail.

Just to the south of the state, a large squall line may evolve along the I35 corridor in KS/MO and even further southward. This line may move northeast, and according to some weather models this line may move into central Iowa from the south giving mainly a threat at significant rainfall. This potential line, along with other showers and thunderstorms from the west will move over the state throughout the nighttime hours. As the low occludes, we will likely see a dry slot move into the state and allow us to at least be dry for most of the day on Thursday. As mentioned with the additional trough moving in Thursday night, additional chances for a mix of rain/snow will come with it. More updates are possible tomorrow afternoon on the evolution of a potential severe weather threat.