A major severe weather outbreak is now expected over parts of northeast Iowa, southeast Minnesota and western Wisconsin. The Storm Prediction Center has expanded the moderate risk slightly into northeast Iowa today. Some of the hottest weather we’ve seen this year could be experienced over parts of the state today with a heat advisory in place for many areas.
This will set up a showdown between the humid air mass and a cold front expected to move through the state. All that warm air will develop a strong cap in the atmosphere that will prevent thunderstorms development for several hours this afternoon. But that cap should begin to break down sometime around 4pm, prime time for severe thunderstorm development.
Storms are expected to first develop in southern Minnesota and spread southward into Iowa. Once things get going, there are some doubts as to the main mode of severe weather. Take a look at the graphic to the right. It indicates the threat of tornadoes today. You can see a maxed out area over southern Minnesota and northeast Iowa. This is the area where isolated supercells could form. If one of these monster storms breaks away and gets out on its own, it would become a prime candidate to produce a strong, long-tracked tornado.
This is an EXTREMELY dangerous situation and I advise everyone under the slight and moderate risk areas today to keep up to date with the latest forecast. Things are expected to take a sudden and violent turn once these storms develop and once they fire, time will not be on the side of those caught in their path.
Turning to the potential for a different kind of outbreak, the Storm Prediction Center has posted the highest possible risk for damaging wind. Extremely strong winds are expected with the storms that develop in this area today. You can see the area outlined in the graphic to the left. If a line of storms quickly forms into an organized system, wind and not tornadoes could become the primary threat over a large area.
All in all this could turn into one of the biggest outbreaks the Upper Midwest has seen all year. Again, I want to stress to everyone to please stay up to date with what’s going on this afternoon as much as possible. We will provide as many updates as we can from the road and pass along what we see as we venture out. Despite our chase, we are going to attempt to launch the live chat at noon today to provide updates. Right now our plan is to begin the day near or just east of the Mason City area. It looks to be a long and very bump day for northeast Iowa.