Minnesota Lakes: Late freeze up

Keep an eye on your favorite lake this week. You may be the first to see a new coating of ice.

Lakes in Minnesota are freezing up at least two weeks later than average this year. Our mild November weather is the reason. You know it’s late when you see fishing boats on Lake Minnetonka on November 30th as I observed this year.

Joel Rosen is a weather observer on Park Lake in Carlton County south of Duluth. My colleague Mark Seeley passes along Joel’s observation from Monday.

“Park Lake is about 40% frozen over this morning (Dec 1) and some of the ice has apparently frozen and re-frozen a few times….I’d have to do some digging in my narratives, but I think it’s pretty rare for this lake to freeze all the way across this late in the year and then open up before re-freezing again. The average date for final freeze-up is approximately Nov 18, and the latest on record is Dec 9, 1998. In that year the lake went through 3 cycles of completely iced over. Overall, it seems that not only is the date for freeze-up getting later, but the frequency of freeze/thaw cycles in November has also increased in the last 10 years. I will send another brief message when Park Lake freezes over for the winter, (likely tomorrow night).”

I will keep an eye on Lake Minnetonka near the weather lab this week to see if the bays begin to freeze up. In the 70’s and 80’s it was common to see people are skating by Thanksgiving weekend.

Please send along any observations of freeze up this week. The data is hard to come by.

Cold Surge: How long will it last?

It’s interesting to watch the GFS model attempt to resolve the duration of this weeks cold snap. Yesterday the GFS was hinting at multiple surges of cold polar air coming south right through mid-month. In the overnight runs, the GFS returns to a zonal (west to east) flow in the northern U.S. in about 10 to 12 days.

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Overnight GFS model run hints at much milder air returning to the Midwest by mid month.

This flow brings milder Pacific air into the region. In fact, the GFS is hinting at a return to (possibly much) above average temps before mid-month. It will be interesting to see if the cold can persist, or if milder air gushes back into the Midwest by mid-month.

Stay tuned!

PH

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