Updraft® - Minnesota Weather News

Heat wave builds next weekend

More 90s ahead. But forecast models vary on heat intensity and duration.

Forecast high temperatures Saturday
Forecast high temperatures Saturday.
NOAA

It’s mid-August. We’re getting into the time of year when weather whiplash can spike temperatures dramatically lower, or higher.

The peak of summer’s heat is generally behind us now. The first anemic cold fronts can bring a September preview. But late-summer sunshine and August air masses are still capable of punching temperatures well into the 90s.

This week brings a temperature roller coaster. Our brisk Monday gives way to sunshine Tuesday with temperatures reaching the 80s once again by Tuesday afternoon.

Forecast high temperatures Tuesday
Forecast high temperatures Tuesday.
NOAA

Highs Wednesday will approach 90 degrees again in southern Minnesota.

Forecast high temperatures Wednesday
Forecast high temperatures Wednesday.
NOAA

The next cool front blows in another day of 70s Thursday.

Heat builds this weekend

The major forecast models have been battling about just how hot it will get this weekend. And for just how long it will say hot.

The European and Canadian models seem to agree on highs in the mid-90s for the weekend across southern Minnesota. Note the heat dome building to the west with temperatures above 100 degrees in South Dakota by Friday.

Forecast high temperatures Friday
Forecast high temperatures Friday.
NOAA

NOAA’s GFS model, on the other hand, seems completely out of control posting temperatures around 110 degrees across southern Minnesota this weekend.

NOAA GFS temperature forecast
NOAA GFS temperature forecast for Sunday, August 20.
NOAA via tropical tidbits

Most meteorologists I speak with assess the GFS model grossly overestimates temperatures in these situations. (You can imagine the back channel banter with Sven, Ron, Bill and me this week.)

NOAA supercomputer
NOAA supercomputers
NOAA

Why is my weather app saying 108 degrees?

The GFS is probably why some weather apps may be cranking out temperatures well above 100 degrees as we move into next week.

Keep in mind that different weather apps use different forecast models or ensembles. I get this question a lot. The best thing to remember is that forecast models are just like people. Most of us are right most of the time, but we’re all wrong sometimes.

Weather forecast models have different biases just like people. Some of us handle certain situations better than other situations. You have to know who to trust in certain situations. The same goes for forecast models.

So it’s usually best to ask a meteorologist who knows the ways different forecast models work and skew about your local forecast. At least in 2023 anyway. Who knows what AI will do for and to weather forecasting in the next 10 years?

Stay tuned.