Major flooding about to return to the Midwest

[PurdueWx80]

A classic mid-summer pattern is about to set up, with a broad ridge building over much of the country. It appears a major and extended flooding event will return to the Midwest in this pattern, starting tonight and lasting well into next week. Tropical moisture will gradually build along the northern edge of this ridge, where a quasi-stationary frontal boundary will waver back and forth through the period. It's a worrisome pattern, especially given already soaked soils and high streamflow from June. At this point, tropical moisture from the Gulf will be fairly slow to return because of the ridging/upper-low setup over the Gulf and South, but as the ridge builds further into the East early next week, deep southerly flow will have no trouble setting up. Until then, evapotranspiration will gradually build atmospheric moisture to impressive levels (surface dewpoints rising well into the 70s, perhaps low 80s, by late this week).

Specific flash flooding threats are hard to pick out at this point and will be until mesoscale details are more certain, but at this time it looks like MN, IA, WI and IL will see the bulk of the flooding once again, which will set the stage for perhaps major flooding along the Mississippi and its tributaries in a couple of weeks. This all starts tomorrow in MN, the way it appears now.

Severe weather will be a secondary concern, but the more impressive pieces of energy traveling across the region will obviously lead to more widespread events.

[RL3AO]

Not good for those in Iowa and further south. Anyway, 5-day QPF.

[Stephanie]

I hope that isn't correct for Iowa and the rest of the soaken Midwest. I do, however, hope that the numbers are right for the East Coast. We're beginning to bake folks.