Our active weather pattern will stretch into the end of the memorial day weekend. With warm and humid conditions over Iowa, center of low pressure and a cold front are expected to serve as the focal point for severe thunderstorm development on Sunday. An outbreak is possible over portions of Nebraska, Minnesota, South Dakota and western Iowa. Although 5 forecast periods out, you can see the area already highlighted by the Storm Prediction Center in the graphic above.
A “triple point” scenario is expected to setup somewhere near the border of South Dakota and Nebraska, just west of Iowa. The final placement of this storm system will greatly impact the final placement of the greatest threat for a tornado outbreak. I do expect some modifications in the forecast as this storm system draws near. That low pressure center should drift well north of Iowa during this event, but that won’t be the end of our severe weather chances.
As I said, a warm and humid air mass will produce some of the most oppressive weather conditions of the season across Iowa on Sunday. With that “loaded” atmosphere, a strong cold front will sweep through the state on Monday, undoubtedly bringing a threat of strong to severe weather. Although too far out to pinpoint an exact threat, this setup has all the hallmarks of a “classic” summer storm system which would indicate an enhanced threat for strong winds. We hope to get a better handle on the threats to Memorial Day as it draws closer.