May 10, 2020: Ice Free

With temperatures below freezing last night and most of this morning, I wasn’t sure if it was safe to say all the ice is gone. The largest patch remaining was on Bigstone Bay, which was going fast on May 8th.  My sources there tell me it vanished yesterday.

So I’m calling Lake of the Woods ice-free as of May 9th this year.

Brick Graph

On the Brick Graph, 2020 falls near the middle of the pack. That’s kind of disappointing for a spring that had relatively thin ice.

You can click on the graphs to see them full-screen.

The “Jenga” or Pancake Graph tracks the thaw from the Inflection Date (when the mean daily temperature rose above freezing on a lasting basis) to the day Lake of the Woods is ice-free. Years are stacked chronologically, with the most recent year at the top. The 2020 final version looks like this:

Pancake Graph

The thaw went fast after the air temperature rose above freezing. It’s probably safe to assume that a lot of the ice was melted from below, by the lake water, before air temperature had a go. This graph doesn’t attempt to factor that in, so it shows this year’s seventeen days as the most rapid thaw in recent years, after getting off to a late start.

The more I learn, the more I realize I don’t know enough. There are so many factors at work: ice thickness, snow cover, air temperature, sunshine, wind, rain, water levels and current. One year, my predicted date will be correct. And you know what? It won’t be from correctly calculating the effect of all those things. It’ll be a fluke.

Speaking of things I’m unqualified to comment on, I had some people ask if I know anything about when the Canada-USA border might open. Well, no, I don’t.

But I can certainly see that it doesn’t make sense let Americans flow freely into the country while we’re still trying to keep Canadians separated from one another to reduce the risk of exposure.

The two countries have chosen very different strategies, and they can’t really be melded. While Canadians are being paid to sit tight, and have the assurance of medical coverage whether they work or not, the US has leaned towards sending people back to work, even going so far as to open places like meat-processing plants despite high rates of infection.

It’s a safe bet that the rate of exposure is much higher in the US than here. It certainly is in places like New York. Until recently, only sick people were getting tested, but we need to know how widespread the infection is in the general populations of both countries.

If the US approaches “herd immunity” numbers while exposure in Canada is still relatively rare, opening the border would cause a huge outbreak here.

So I think it might have to wait a while, and it’s quite likely going to cause problems of one kind or another.

 

 

4 thoughts on “May 10, 2020: Ice Free

  1. Thank you again for your reports. It has become as much a sign of spring to me as the Robin’s return. Many many thanks.

    Joy Bowman (Sioux Narrows summer resident)

    On Sun, May 10, 2020 at 8:50 PM Lake of the Woods Ice Patrol wrote:

    > icecaptain posted: “With temperatures below freezing last night and most > of this morning, I wasn’t sure if it was safe to say all the ice is gone. > The largest patch remaining was on Bigstone Bay, which was going fast on > May 8th. My sources there tell me it vanished yesterda” >

  2. Hi wow with night temps hitting minus double digits I thought the lake would re freeze ..jusk kidding…but that should be it for cold temps ..I hope

  3. I know you have called the LOW ice free, but I wanted to comment that Shoal Lake also now appears to be ice free. I downloaded the Sentinel-2 image from yesterday and I could not identify any ice on Shoal Lake. I am not sure how to send you an image, but I have extracted about a 1MB bitmap image of most of Shoal Lake if you are interested.

    I am sure glad that you turned us on to the Sentinel product, I am interested in ice out on some of the trout lakes to the east that you do not comment on. However, for anyone interested in using the images, be prepared for a bit of a learning curve. So far I am about up to the Kindergarten level, much more to go, sigh. But something to do while socially distancing.

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