Severe Weather Potential - June 17

The potential is there for significant severe weather across the western half of Iowa this afternoon and into the overnight hours. All modes of severe weather appear possible, including damaging winds, very large hail, and tornadoes. There are two areas of concern for severe weather today, both of which cover western Iowa...

The first and most likely concern will be over much of western Iowa, and likely be during the late evening or overnight hours. This severe weather threat will likely be for damaging winds and large hail, although a risk of tornadoes will exist, a more linear nature of thunderstorms may be expected. These thunderstorms will evolve from central Nebraska this afternoon as they initiate due to a shortwave and frontal system interaction. As the thunderstorms continue to evolve eastward they are likely to congeal into a more linear MCS capable of large hail and damaging winds as they enter into western Iowa.

Another threat for severe weather will exist during the afternoon/evening hours over mainly northwest Iowa, as well as southwest Minnesota. Similar to yesterday afternoon over South Dakota, a weak low pressure system in conjunction with a trough of low pressure and low level convergence may lead to thunderstorm development along a weak wind shift line. With even higher temperatures and dew points this afternoon yielding even higher instability amounts this will come as no surprise to see even stronger supercells off of this setup. These storms will be capable of all modes of severe weather through the evening hours, but similar to yesterday they should begin to weaken after sunset.

Additional updates are likely this afternoon as the severe weather threat evolves, I am watching the potential across northwest Iowa for the tornadic supercells similar to yesterday...