6:00 PM Monday, September 11, 2023
An upper-level low and upper trough covered the upper Midwest and western Great Lakes today, and this system combined with colder temperatures aloft (500mb temps around -20C) and some warmer air near the surface led to the development of scattered showers and a few thunderstorms in northeast Minnesota and northwest Wisconsin today with heavy downpours in some locations. Note — There have also been a few reports of small hail with the strongest storms this afternoon especially around the Brainerd Lakes area with a couple reports of hail up to half inch and nickel size.
Additional rainfall amounts in the Northland tonight and Tuesday are forecast to range from around 0.10″ to 0.25″ with locally higher amounts upwards of 0.50″ to 0.75″.
Radar loop ending 4:05 PM CT, Monday, September 11, 2023.
Goes-16 water vapor loop from Monday, September 11, 2023 (loop time ends 4:01 PM CT)
Scattered rains will continue in the Northland tonight and Tuesday although the coverage of the rain should be on a diminishing trend once we get to Tuesday afternoon.
NAM 3km model radar forecast through 7 PM Tuesday.
We did see one batch of heavy downpours and thunderstorms move through Duluth between 2-3 PM this afternoon with some parts of Duluth picking up around an inch of rain per radar estimates.
Rainfall Reports from Monday, September 11, 2023
Source: MesoWest
Note — Totals below are through 5 PM Monday.
Saginaw, MN: 0.61″
Deer River, MN: 0.44″
Brainerd, MN: 0.16″
Barnes, WI: 0.15″
Washburn, WI: 0.15″
Isabella, MN: 0.14″
Hayward, WI: 0.14″
Duluth Airport: 0.11″
Longville, MN: 0.10″
Poplar, WI: 0.09″
French River, MN: 0.08″
Solon Springs, WI: 0.07″
Cass Lake, MN: 0.06″
McGregor, MN: 0.05″
Grand Rapids, MN: 0.04″
Duluth Sky Harbor Airport: 0.03″
Walker, MN: 0.03″
International Falls, MN: 0.03″
Bigfork, MN: 0.02″
Ely, MN: 0.02″
Hill City, MN: 0.01″
Clam Lake, WI: 0.01″
Siren, WI: 0.01″
Moose Lake, MN: 0.01″
Minong, WI: 0.01″
***FROST POTENTIAL LATE TUESDAY NIGHT/EARLY WEDNESDAY MORNING***
Chances that we see the first widespread frost event of the season are increasing in much of the Northland late Tuesday night/early Wednesday morning with temperatures dropping into the 30s with even a few 20s possible in a few locations. Note — Warmer temperatures are expected closer to Lake Superior with no frost the way it looks now.
Cooler than average temperatures will continue in the Northland through midweek followed by warmer temperatures late this week, especially for Thursday and Friday when we should see widespread 70+ degree temperatures during the afternoon.
Long range computer models are showing a potential for above to even well above average temperatures in the Northland for next week, so it doesn’t look like we’re done yet with 70-degree temperatures for the year.
GEFS model agrees with the EPS model on the temperature forecast next week.
Oldest run is days 10-14 on the loop below, and the newest run is days 8-12.
Orange and reds on the loop below represent above average temperatures.
Last week was very wet in parts of the Northland especially near Lake Superior where rainfall totals for the week were some 200 to 300% or more above average.
Rainfall total at the Duluth Airport from September 3rd through the 9th was 3.10 inches. Normal rainfall during that period is 0.83 inches. The Airport was +2.27″ above average in rainfall last week, and we saw 373% of our normal rainfall, or in other words well above average.
Thanks for reading!
Tim