Twin Cities growing season hangs by a thread, frosty week ahead

We're on the board for the  first snow and snowmen and women of the season in many central and northern Minnesota communities.

Sunday's snowy greeting brought 1" to 2" to Sartell, St. Cloud, Mille Lacs into northern Wisconsin Sunday. An isolated 5 inch snowfall total came in from Askov in Pine County.

A few flakes found their way into the north metro Sunday but most of the Twin Cities was spared the drama of October snow, at least  for now. Still Saturday's mini sleet storm had to get your attention. It sleeted long enough and hard enough to cover the deck at the weather lab in the west metro with ice pellets.

It's a reminder that the season is changing, and wintery weather is never too far away in Minnesota.

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55 degrees average high for the Twin Cities this week

37 degrees average low at MSP Airport this week

-10 to -15 temps vs. average this week in Minnesota

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Image: Twin Cities NWS

Cool week ahead

The week ahead channels November in Minnesota. The weather on.off switch is on again, and the late summer warmth of the first 12 days of October has been kicked to the proverbial weather curb. Temps will run at least 10 degrees below average this week.

The La Crosse NWS does a nice job of explaining the Midwest upper air pattern this week in today's 'Weather Story.'

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Image: La Crosse NWS

Growing season ends

Temps bottomed out at or below 32 degrees in most of Minnesota over the weekend. The only exception is the inner metro core, where the urban heat island has kept away the first freeze so far. That won't last as a string of nights in the upper 20s takes hold this week. There will be no doubt by later this week that the growing season has ended, even in the downtowns.

Here's the Euro model look at temps this week.

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Image: Weatherspark

It look like we'll finally hit 32 degrees Tuesday morning at MSP. If we do that will be 181 days between the last 32 degree temp on April 24th and the first 32 degree shot this fall. That's about 2 weeks longer than the 30-year average of 167 days for the growing season at MSP.

The Minnesota Climate Working Group elaborates on the usefulness of 'growing season' data.

The dates of the last freezing temperatures of the spring and the first freezing temperatures of the fall are of great importance to home gardeners, commercial horticulture, farmers, agribusiness, and others. These dates are sometimes referred to as "last frost" and "first frost".

Accurate long-range forecasts of freeze dates remain beyond the reach of science. Therefore, climatologists rely on past temperature observations to calculate the historical probability of freezing temperatures occurring after (spring) or before (fall) certain dates. Users can use these probabilities to make decisions based on their tolerance for risk.

The growing, or 'frost free' season in Minnesota has increased by about 9 days in the past century according to data from Climate Central.

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Image: Climate Central

Fall color past peak up north

White is the new colo up north these days. Here's the updated fall color report from the Minnesota DNR.

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Image: Minnesota DNR