Strong to severe t-storms possible in parts of the Northland through late tonight

…There is a chance for strong to severe thunderstorms in Northeast Minnesota and Northwest Wisconsin from late this afternoon through late tonight…

The Storm Prediction Center has put most of the Northland in a Slight Risk for severe thunderstorms through tonight per their update from late Wednesday morning.

One round of showers with embedded thunderstorms has been lifting east/northeast across northeast Minnesota into far northwest Wisconsin this morning/early this afternoon. Heavy downpours and occasional lightning has occurred with this activity.

Note: Radar loop below ending at 12:45 PM Wednesday.

Where storms develop later today is still somewhat uncertain, but I think the corridor in between the two red lines on the image below has the greatest chance for possible severe weather later this afternoon into this evening. This area will be located just north of the cap which will be in place in southern Minnesota. Storms tend to follow the +10 to +12C 700mb temperature contour, anything around or warmer than +12C at 700mb is often too warm for thunderstorms.

Stronger mid to upper level winds of 40-60 knots currently over the Northern Plains will spread into the upper Midwest by this evening while skies clear in wake of the MCS (Mesoscale Convective System) which is rolling east/southeast through Iowa early this afternoon. The atmosphere is forecast to become very unstable by late this afternoon across western and southern Minnesota, and possibly a little farther north as well. The combination of strong instability, a very warm and humid airmass, stronger winds aloft and favorable amounts of wind shear will be in place for possible severe thunderstorms capable of producing large hail and damaging winds, and possibly a few tornadoes due to the amount of wind shear that is in place.

Heavy rainfall is a threat as well where these storms setup through tonight with pockets of 1 to 3 inch plus rainfall totals possible. Flash flooding could develop in some parts of the area if thunderstorms move across the same location for a few hours.

Image below is from the HREF model.


And this image is from the NAM-WRF model from Wednesday morning showing potential rainfall totals through 7 AM Thursday.


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