6:55 PM Sunday, May 8, 2022
-An active week ahead with chances for showers and thunderstorms on Monday, Wednesday night-early Thursday, with possibly some more rain at times next weekend.
-Much of the Northland will warm into the 70s and maybe even into the 80s on a few days this week (days this week with greatest shot of 80+ degree temps include Monday, Thursday and Friday). Closer to Lake Superior the warmest days this week look to be on Tuesday, and possibly again on Friday, those days could have temperatures well into the 70s even by the big lake!
-We should get our first 70 of the year in Duluth this week, if it doesn’t happen on Monday, then Tuesday would be our next shot of hitting 70 degrees. The average date for first 70-degree high temperature at Duluth is April 23rd.
-A pattern change is possible early next week which could lead to some snow or a rain/snow mix in the Arrowhead of Minnesota.
Isolated strong to severe thunderstorms are possible in the Northland on Monday especially in the dark green area on the map below.
A round of showers and thunderstorms could affect parts of the Northland Monday morning (after 7 AM) with storms moving from southwest to northeast. This round of convection would be associated with a northward moving warm front while a strong low-level jet advects warm and humid air with increasing amounts of elevated CAPE into our area. Hail, heavy downpours and lightning would be the main threats if storms develop Monday morning with a chance for a few severe storms capable of producing large hail of quarter size to ping pong ball size (1.00″-1.50″ diameter).
What happens late Monday afternoon through Monday evening is uncertain as it will depend on the amount of clearing that takes place Monday afternoon and the timing of a cold front which approaches from the west. Very warm temperatures will spread in aloft leading to a capped atmosphere with 700mb temperatures as warm as +14C, and if forcing isn’t strong enough with the cold front, then it’s unlikely will see any additional thunderstorms develop later Monday afternoon. There is also some uncertainty on the timing of higher quality moisture (dew points 55 F or greater) and if there will be enough recovery time for instability to rebuild later in the day on Monday. However, if things do come together in time, then we could see a few strong to severe thunderstorms redevelop late Monday afternoon through Monday evening mainly from northeast into far eastern Minnesota and in northwest Wisconsin.
Winds aloft look very strong on Monday with 500mb winds approaching 120 knots over northwest Minnesota while 850mb winds (lower levels of the atmosphere) range from around 40 to 60 knots across the Northland. 0-6 KM Bulk Shear is forecast to range from 50 to 70 knots with Effective Bulk Shear up to 40 knots. All of these ingredients are very sufficient for severe weather, but with Monday’s setup it’ll come down to whether or not the cap can break, how warm we get and if enough clearing can occur to build up enough instability later Monday afternoon.
A few different computer model simulated radar forecasts
NAM 3km model valid Midnight tonight through 7 PM Monday.
HRRR model valid Midnight tonight thru 10 PM Monday.
Currently the HRRR model is much more bullish compared to the NAM 3km model with a second round of storms firing up late Monday afternoon in parts of the Northland.
Rainfall Totals for Sunday, May 8, 2022 (thru 6 PM)
Bigfork, MN: 0.43″
Orr, MN: 0.34″
International Falls, MN: 0.33″
Isabella, MN: 0.30″
Saginaw, MN: 0.29″
Duluth Airport: 0.27″
Hibbing, MN: 0.25″
Littlefork, MN: 0.25″
Two Harbors, MN: 0.24″
Cass Lake, MN: 0.24″
Walker, MN: 0.22″
Cloquet, MN: 0.21″
Brainerd, MN: 0.17″
Hill City, MN: 0.13″
Minong, WI: 0.13″
Hinckley, MN: 0.12″
Pine River, MN: 0.10″
Duluth Sky Harbor Airport: 0.09″
Superior Airport: 0.08″
Ely, MN: 0.07″
Moose Lake, MN: 0.06″
Siren, WI: 0.06″
Solon Springs, WI: 0.05″
Hayward, WI: 0.03″
Grand Marais, MN: 0.01″
Heavy rain may lead to flash flooding tonight through Monday evening for parts of eastern North Dakota into northwest and possibly into north-central Minnesota.
A very wet spring with more rain on the way this week will lead to more river flooding or continued river flooding in northern parts of the upper Midwest.
-Significant River Flooding is occurring in red.
-Significant River Flooding is likely in orange and is possible in yellow.
Sometimes on the north side of an approaching thermal ridge you’ll get some thunderstorms to develop, and this is why there is a possibility for a few storms in the Northland Monday morning.
South of the aforementioned thermal ridge temperatures will be very warm with strong southerly winds on Monday. This thermal ridge along with its very warm temperatures will be spreading farther north/east into parts of the Northland Monday afternoon.
Temperatures near the Iowa border (along Interstate 90) could flirt with 90 degrees Monday afternoon, with 80s as far north as the Brainerd Lakes to Hinckley to Siren areas. 60s and 70s are forecast farther north on Monday with much cooler temperatures near Lake Superior.
Note: The warmest temperatures on Monday might not arrive until later in the afternoon (after 2-3 PM) in much of the Northland.
Another round of showers and thunderstorms with a threat for heavy rain is possible Wednesday night into Thursday morning as a warm front lifts north out of Iowa.
Looks like we may see a pretty drastic shift in the pattern from this week to next week.
This week’s pattern is all about the massive upper-level ridge stretching from the southern Plains to the Midwest, Great Lakes, and eastern Canada with upper-level lows west and east of the upper ridge.
Here’s the temperature anomaly forecast based on the expected pattern this week.
As we get into next week there are signs showing up in model forecasts for a change in the pattern once again with more of a NW flow possibly setting up from the Midwest to the Great Lakes into the northeast U.S. while an upper-level ridge develops over the southwest U.S.
Here’s the temperature anomaly forecast for next week based on how the pattern evolves next week.
There’s even a possibility that we may see a little snow, or a rain/snow mix in far northeastern Minnesota early next week (around May 16-17).
Thanks for reading!
Tim