at 8:08 AM by Pierce Larkin

Incredible Flooding in Minnesota

On Monday evening, a boundary that was laid across northern Minnesota and Wisconsin by overnight convection was a forcing mechanism and a steering mechanism for heavy rainfall. The region saw multiple rounds of convection throughout the day, and this rainfall trained over the region for hours.

The radar loop from the morning of July 11 to the morning of July 12. h/t UCAR Archive
The radar loop from the morning of July 11 to the morning of July 12. h/t UCAR Archive

The environment was prime for crazy amounts of rainfall across the region. A boundary laid across the region provided additional lift to the ascent within the atmosphere seen within other atmospheric diagnostics.

The black line is boundary across northern Minnesota and northwestern Wisconsin. Looking at the precip analysis, the precip followed this well. h/t SPC
The black line is boundary across northern Minnesota and northwestern Wisconsin. Looking at the precip analysis, the precip followed this well. h/t SPC

This boundary was overlaid by a large pool of highly anomalous precipitable water values going on 2.2″. The evening sounding out of Minneapolis showed PWAT values of 1.98″, and the max moving average for July 12 at 00z is only 1.88″. The atmosphere present across central and northern Minnesota and northwestern Wisconsin was historically anomalous.

The observed sounding from Minneapolis. Note the high values of precipitable water boxed in red. h/t SPC
The observed sounding from Minneapolis. Note the high values of precipitable water boxed in red. h/t SPC
The precipitable water value climatology for Minneapolis. The stats for July 12 at 00z are plotted on there. h/t SPC
The precipitable water value climatology for Minneapolis. The stats for July 12 at 00z are plotted on there. h/t SPC

This led to anomalously high rainfall in a short period of time, but also significant flash flooding. Some of the rainfall in a 24 hour timespan across northern Minnesota and northwestern Wisconsin totaled greater than 10″.

Wow! h/t NWS Duluth
Wow! h/t NWS Duluth

Check out some of the wild images out of the region, and some of the peaks from rivers across the region.

Check out the wild rise in this river in Wisconsin. h/t NWS Duluth
Check out the wild rise in this river in Wisconsin. h/t NWS Duluth
h/t NWS Duluth
h/t NWS Duluth

Flooding events like these are never good, so keep these folks in your thoughts and prayers as they go through it.