The Labor Day weekend will start with a threat for severe weather in the Upper Midwest and the Great Lakes. Strong jet stream energy coupled with increasing humidity will provide the right ingredients for severe storms to develop.  Warm temperatures and ample moisture will lead to substantial instability, maintaining severe thunderstorm growth.

On Saturday, the risk area is focused from eastern South Dakota to near the Mississippi River in Iowa and Illinois. There is en enhanced risk (level 3 out of 5) in Southwestern Minnesota, and a slight risk for severe thunderstorms in southwestern Minnesota and northern Iowa.  Large hail, greater than two inches in diameter, is the biggest threat. A few strong wind gusts over 60 mph are also possible.

Development will be slow throughout the afternoon, with a few storms forming along a warm front in the evening. Storm development will increase in the late night and overnight and may continue into early Sunday morning before diminishing. Along with the severe threat, thunderstorms may produce very heavy rain.

As the storm system continues to move to the southeast, a few severe thunderstorms are possible on Sunday. There is a marginal risk for severe weather from eastern Iowa and southeastern Minnesota through southern Lower Michigan and far northwestern Ohio. A slight risk has been issued between Cedar Rapids and Southwestern Michigan.

Storms on Sunday will also be capable of producing damaging winds and large hail. Some isolated severe storms will be possible early Sunday, leftover from Saturday nights convection, through the bulk of the severe weather threat will occur late in the day and overnight again as the cold front moves across Lake Michigan and toward Lake Erie.

WeatherNation will keep you up-to-date on the severe weather risk for the Labor Day weekend on-air and online.