Colder Alaskan air may reach Minnesota late next week

Have you looked at the calendar lately?

It’s hard to believe, but September arrives a week from Sunday. How did that happen, exactly? It seems like the Fourth of July was just last week.

Many of us do this every year in Minnesota. We savor the last days of summery bliss. We ignore the calendar as it inexorably creeps toward September. We act as if summer will linger for at least another month.

But the weather maps don’t lie. The jet stream is creeping slowly southward once again, and it’s already snowing in Alaska.

Which brings me to the point of this post. There are signs the first real fall cold front of the season may sweep through Minnesota in about 10 days.

The National Oceanic and Atmospheric Administration’s Global Forecast System model upper-air pattern shows the trend. The forecast model loop below runs between Saturday and Friday, Aug. 30.

See the transition from warmer ridging this weekend to a cold pool of air racing southeastward from Canada by late next week?

Now, the Global Forecast System model could be overdoing this trend. It’s notorious for being overly extreme in the one to two-week range. But the typically trusty European Centre for Medium-Range Weather Forecasts model also suggests much cooler temperatures late next week.

Tuesday morning’s European model run suggests temperatures in the 50s north and 60s south by early evening next Thursday, Aug. 29.

NOAA’s eight to 14-day temperature outlook favors near-normal temperatures. I won't be surprised to see the map below updated in the coming days to include some blue areas of cooler-than-normal temperatures for late next week.

The normal high and low temperatures for the first week of September in the Twin Cities are 77 and 59 degrees.

We may be feeling the first true taste of fall in about 10 days!

Stay tuned.