6:21 PM Sunday, April 27, 2025
Scattered showers and thunderstorms are expected in the Northland late tonight and into Monday morning, possibly bringing heavy rain, lightning, and small hail under 1 inch in diameter.
Additional showers and storms are expected on Monday afternoon and evening.
Rainfall of up to an inch or more is expected across the Northland by early Tuesday morning.
Scattered strong to severe thunderstorms are possible in all of northeastern Minnesota and northwestern Wisconsin on Monday into early Monday evening, according to the Storm Prediction Center.
The chances for severe weather appear highest across southern areas of the Northland on Monday, with lower chances in northern Minnesota.
The Storm Prediction Center in Norman, Oklahoma, will update the outlooks below by 1 AM Monday, with further updates around 8 AM, 11:30 AM, and 3 PM.
Tornado chances in the Northland, particularly from east-central Minnesota into parts of northwest Wisconsin, will be dictated by storm mode as well as the northward extent of warm and humid air Monday afternoon.
If the storm mode is messy, meaning more of a line vs. scattered activity, this may lessen the tornado risk, and if storms linger throughout the day, this will probably restrict the northward advancement of enough warm and humid air to support a chance for tornadoes later Monday afternoon.
Note: I think the chance for any tornadoes will stay south of the Duluth Area late Monday afternoon to early evening.
Hail up to the size of golf balls or larger is possible with some of the storms in the Northland on Monday.
Winds of up to 60 mph may occur with some storms in northeast and east central Minnesota and northwest Wisconsin on Monday.
Here’s the SREF model’s calibrated probability of severe thunderstorms for 7 PM Monday, rated on a scale from 3 to 15, where 3 is low and 15 is high.
Parts of central and eastern Minnesota, as well as far western Wisconsin, have values between 7 and 13 on Monday afternoon and evening, with values dropping to around 5 for Duluth and northwest Wisconsin, and around 3 for the North Shore.
One thing I like to do is show different model outcomes when it pertains to thunderstorm forecasts.
Here’s the RRFS-A model valid 1 AM Monday to 10 PM Monday.
And here’s the NAM 3km model valid 1 AM Monday to 10 PM Monday.
Both models include morning activity, but they differ in the afternoon and evening. The RRFS-A model is the stronger option for storms during Monday afternoon and evening.
A strong jet streak of around 70 knots or greater will spread northeast through the upper Midwest on Monday ahead of an approaching upper-level trough. The strong winds aloft and the approaching trough should create quite a bit of lift in the atmosphere, while the strong winds aloft also aid in the potential for severe thunderstorm development in parts of the upper Midwest.
The euro model strongly pushes warmer air north into southern parts of the Northland on Monday afternoon, with temperatures reaching the 60s and 70s, while other models keep the warmer air further south.
Note the 80s in southwest Minnesota as that will be part of an elevated mixed layer (EML) that will help to enhance the mid-level lapse rates on Monday, which could increase the risk for storms to be efficient lightning producers and hail producers.
Typically for severe thunderstorms, dew points should be around 55 to 60 or higher. Dew points of at least 60 are expected to reach central Minnesota by early Monday afternoon and may extend further east-northeast later in the afternoon.
Upper low is moving northeast over the southern Rockies today with lower 500mb heights.
As the trough moves toward the Northland, it will lower the 500mb heights, and southerly winds will bring more moisture into our area on Monday.
Goes-16 enhanced water vapor loop ending 6:06 PM CT Sunday, April 27, 2025.
Surface map for early Monday afternoon shows low pressure over northeast South Dakota, which will continue to lift northeast through Monday evening, with a warm front (red) advancing northeast while a cold front (blue) heads east.
Thanks for reading!
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