Not a lot of updates to share about severe weather on Wednesday with the current forecast, published yesterday, still on track. A pair of low pressure centers in Manitoba and in northern Minnesota with an associated cold front extending into the Upper Mississippi Valley into the Central Plains looks to set the stage for severe weather potential on Wednesday.
The Storm Prediction Center has outlined an elevated risk of severe weather for most areas west of Interstate 35 with a marginal risk for most everywhere else, with the exception being those in the far southeast. Temperatures on Wednesday look to be summer-like with lower 70s across the east to the lower 80s west. There will also be a lot of moisture available to tap into with dew points in the 50s and 60s across the state. There will likely be a cap in place early in the day, but this will erode as we get into the evening hours. When combining with this with moderate instability and decent 30-40 kt shear, large hail and damaging wind potential will exist across the region Wednesday night. The tornado potential is expected to be mitigated with unidirectional (one specific direction) winds aloft.
We expect storms to begin firing up in the early to mid afternoon hours on a diagonal from the Twin Cities area to Hays, Kansas and advance southeast during the evening. Large hail threat will be the primary threat initially before storms begin to become more linear and change over to a damaging wind threat. Approximate timing for cities are listed below:
- Sioux Falls 2-3 PM
- Sioux City 4-6 PM
- Omaha/Council Bluffs 6-7 PM
- Denison 6-7 PM
- DSM/Ames 8-9 PM
- Mason City 8-9 PM
- Waterloo 11 PM-1 AM
- Ottumwa 12-2 AM
- Cedar Rapids/Iowa City 1-3 AM
- Dubuque 2-4 AM
- Quad Cities 5-6 AM (if not dissipated by that point)
The threat of strong to severe storms will exist up until about midnight before it becomes more marginal overnight with only a few localized damaging wind gusts. Storms then look to move into southeast Iowa and far northwest Illinois by the early morning hours Thursday if they have not dissipated by that point.
Stay tuned to the Iowa Weather Network for the latest information!
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