The weather during the day on Monday looks fine in northeast Minnesota and northwest Wisconsin with a cool start to the day, but temperatures will warm into the 70s Monday afternoon as southerly winds increase.
There could be some rain Monday night into early Tuesday morning as a potent system digs SE into the Northland. Will see those southerly winds on Monday advect some moisture northeastward into our area ahead of Monday night’s system, and this combined with some lift accompanying a surface low, warm front and cold front should be enough to cause some showers and thunderstorms across the Northland by mid or late Monday evening and continuing into the overnight hours.
Chances for a few showers or thunderstorms will continue Tuesday as the Northland will remain under a NW flow aloft while a strong trough continues to affect the area.
18z NAM model 500mb vorticity forecast valid from 7 PM Monday to 7 PM Tuesday.
Forecast map valid for late Monday afternoon.
A rather strong SW low level jet is forecast to develop Monday evening across the the Northland which should help pull some of that higher CAPE in west-central Minnesota northeast into parts of northeast Minnesota and northwest Wisconsin by late Monday night, with elevated CAPE possibly reaching 750-1500 J/kg in our area by late Monday night, this combined with steepening mid level lapse rates, strong winds aloft and strong wind shear could lead to a few severe thunderstorms in our area by late Monday evening or overnight, with large hail being the main threat due to little surface-based instability which should lessen the potential for damaging wind gusts.
The Storm Prediction Center has put northern Minnesota and far northern Wisconsin in a Marginal Risk (dark green) for Severe Thunderstorms Monday night, while non-severe thunderstorms are possible in the light green area.
12z European model radar forecast valid from 7 PM Monday to 7 AM Tuesday.
Note: Showers and thunderstorms are possible in Duluth and Superior starting ~9 to 11 PM Monday.
18z NAM 3km model radar forecast valid from 7 PM Monday to 7 AM Tuesday.
This model is somewhat slower than the European model, and shows most of the showers and storms occurring around or after Midnight Monday night/Tuesday morning.