The Storm Prediction Center in Norman, Oklahoma has posted a moderate risk of severe weather for today. Several ingredients have came together for a severe weather outbreak tomorrow with several violent tornadoes, widespread large hail to two inches in diameter, damaging winds, and flash flooding all possible. An upper level trough is expected to move into the four corners region (Arizona, New Mexico, Utah, and Colorado) on Sunday with southwest winds providing moisture for the region. A cold front will be set across the Plains with a warm front across the Mid-Mississippi Valley.

There is one concern that makes this forecast very conditional, and that is whether we get nocturnal thunderstorms overnight and how long the atmosphere will be allowed to destabilize. This could easily switch off any severe weather and this will be further addressed later this morning. Our thinking is that while we expect some thunderstorms in the Plains and Mid Mississippi Valley overnight, we do expect there will be enough time to allow the risk areas to warm and destabilize. This will pave the way for the severe weather threat later today.

Models have come into a lot of agreement on the timing with the majority of Sunday. Widespread thunderstorms are expected to begin developing by late afternoon and will be in a very unstable air mass, and when in combination with deep layer shear, organized severe thunderstorms should begin to develop with all modes of severe weather possible. Several large, violent, and long track tornadoes will be possible across the area along with large hail (potentially greater than two inches in diameter) and damaging winds in excess of 70 MPH. The greatest risk of tornadoes look to be near central Iowa. This will be especially dangerous as, a. it is a large population center and b. there will be a large event going on at the time – LAZERfest in Des Moines.

We strongly advise you to pay VERY close attention to the weather tomorrow. Review your tornado safety rules and what you are going to do with your kids. If there’s a Tornado Warning, remember to seek shelter immediately, get to an interior room on the lowest floor of a building or office. Stay away from windows. In in a mobile home, car, or outside, move to the closest substantial shelter and protect yourself from flying debris.