It’s a hot one away from Lake Superior this afternoon, check out some of these heat index values from 3 PM Friday, July 24, 2020.
Hallock, MN: 111 F
Madison, MN: 108 F
Crookston, MN: 105 F
Roseau, MN: 105 F
Warroad, MN: 105 F
Fergus Falls, MN: 103 F
Brainerd, MN: 102 F
McGregor, MN: 96 F
Grand Rapids, MN: 95 F
Orr, MN: 94 F
Bigfork, MN: 93 F
Hibbing, MN: 92 F
Heat Advisory in effect until 8 PM this evening for portions of east-central Minnesota including Walker, Cass Lake, Brainerd, Aitkin, McGregor, Hinckley and Pine City. Heat index values of 98 to 102 degrees into early this evening.
Dew point temperatures have climbed into the oppressive range this afternoon with widespread 70-75 degree dew points across Minnesota into western-northern Wisconsin, with even some lower 80s dew points showing up in northwestern Minnesota this afternoon, incredible!
Looks dry across the Northland tonight, but some showers and thunderstorms could work their way into north-central Minnesota overnight. Severe weather is not expected tonight, but some lightning and downpours will be possible with the storms in northern Minnesota late tonight. A warm night away from Lake Superior with lows tonight in the 60s and 70s.
Things just aren’t lining up for much of a severe threat for Saturday despite all the warm and humid air. Some rain will likely continue into Saturday morning across parts of the Northland with maybe an isolated thunderstorm as well, but for the most part this looks like a light to moderate rain, but it’s also possible that a lot of the rain will fall apart as it moves farther east out of northern and central Minnesota Saturday morning.
Saturday afternoon into Saturday night will feature lingering cloud cover which will limit how warm and unstable we get, thus really limiting the potential for strong to severe thunderstorms across the Northland.
Will probably see scattered showers and storms redevelop in northeast Minnesota and northwest Wisconsin Saturday afternoon or Saturday evening with downpours and lightning being the main hazards from this activity.
Highs on Saturday will be in the 70s and 80s, but a few 90s are certainly possible especially over northwest Wisconsin.
As for rainfall totals this weekend – Looks like much of the Northland has a chance to get around a half inch of rain, but a corridor from east-central Minnesota into northwest Wisconsin has a chance to get over an inch of rain. Note: Locally higher rainfall amounts are possible in and near thunderstorms.
The actual cold front won’t be moving through the Northland until Sunday morning or early Sunday afternoon, a bad time for a front to come through if you want storms, so outside of a few showers in eastern Minnesota and northwest Wisconsin on Sunday, most of the day looks dry at the moment, and there will be a big drop in dew points on Sunday once the cold front passes, going from 65-75 degree dews ahead of the front, down to the 50s once the cold front moves through. Highs on Sunday are forecast to range from the upper 70s to middle 80s.
Check out the drier air (much less humid conditions) which moves SE across the Northland Sunday afternoon as shown by the blue and light yellow colors on the animation below which represent dew points in the upper 40s to around 60 degrees!
Source: 18z NAM 3km model 7/24/2020; https://weathermodels.com/
Saturday is going to be a soupy day meaning the atmosphere is going to be loaded with moisture!
Check out the Precipitable water values forecast for Saturday afternoon per European computer model, incredibly high values, probably will be at or near record levels for July 25th at some soundings across the upper Midwest.
Any thunderstorm that develops on Saturday will be able to produce a lot of rain in a short amount of time given the amount of moisture available in the atmosphere, luckily the computer models aren’t showing any signs of training convection across the Northland which should limit the threat for widespread flooding on Saturday, but localized flash flooding is still possible in parts of the Northland on Saturday, especially over east-central Minnesota and northwest Wisconsin.
18z NAM 3km model simulated radar forecast valid from 7 PM this evening to 7 AM Sunday.
Thanks for reading!