April 27, 2020: Jason Duguay / Sean Cockrem

Here are the latest pictures from Jason Duguay, taken from the ORNGE helicopter yesterday.

You can click on these pictures to see them full-screen and zoomable. That’s worth doing, by the way: you can get a much better idea of the condition of the ice, even in the distance.

Devil’s Gap, with Goat Island and Johnson Island sitting at the edge of the ice.

Rat Portage Bay, with Gun Club Island in the middle.

West end of Coney Island, and the Yacht Club end of Keewatin Channel.

I’ve been asked about predictions. There are two ways we can do this: science, and history.

Let’s start with Sean Cockrem, who does the science.

To recap, Sean gauges how cold the winter was by totalling up the mean daily temperatures for all the days where the mean was below freezing. That gives him an idea of how the ice thickness might compare to recent winters. Based on other winters, he calculates how many warm days we might need to thaw that amount of ice. Then he goes to the long-term weather forecast (which has let us down before) to try and work out an approximate date when we should accumulate enough heat to melt all the ice.

We had a warm spell in late March, and it looked as if the thaw might be under way. Then the first three weeks of April were miserably cold. Not just below average, but mostly below freezing, and sometimes way below. If we melted a little ice in the afternoon, we refroze it overnight. So Sean’s original interpretation that we could say the inflection date–when the mean daily temperature rose to be consistently above freezing–could be pegged at March 26, had to be revised. By nearly a month! We finally turned the corner on April 22nd.

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

Here’s a graph that compares the severity of the last few winters.

Each winter is depicted as a downward spike. The colder the winter, the deeper the spike. And the longer the winter, the wider the spike. Last winter, at the right hand side of the graph, was not terribly cold, but you can see how it dragged on, and right at the tip of the spike is our nasty little cold snap, shaped like a little claw.

Okay, so we know what kind of winter it was. What can that tell us about the thaw?

On this graph, the lines all begin on the inflection date, but the dates shown are for this year. The idea is to show how 2020 compares to the best and worst years if you line them all up at the starting gate.

The blue line is 2020, with dots for each day’s actual mean temperature. Looking ahead, the yellow line shows how it will go if the weather forecast comes true.

Part of this prediction is an educated guess. Because we know late springs tend to melt faster than early ones, Sean chose a thaw index that takes into account longer sunnier days, instead of just blindly applying the same mathematical formula. His tentative conclusion? We still need about three weeks to get the lake entirely ice free, and we should make it just in time for the May long weekend, which is early this year, at mid-month.

Before I had Sean crunching numbers, I made predictions in a rather simpler way: I looked through my archives to find pictures that showed a similar extent of ice, and then I checked to see how long it took to melt that time.

You can do this yourself, if you like. There’s an archive tool on the Ice Patrol website that lets you look through the previous several years month by month. I have pictures from April 25th from both 2018 and 2019, and it looks as if this year is kind of in between, but roughly the same.

Here’s what I call the “Jenga Graph” it shows a stack of sticks, with each one representing a thaw starting on the inflection date and ending on the day the lake was 100% ice free. The most recent years are at the top, and 2020 is pale blue because it’s just a guess.

This graph reveals that we really did get a late start on the thaw this year. Of all the years since 2008, only 2013 had a later inflection date than 2020. That doesn’t have to mean the ice will last longer, though. Although the ice has been reluctant to melt, it was not very thick this year.

So it looks as if Sean and I agree pretty much to the day. That doesn’t mean we’ll be right, of course! We’ve been wrong before. Sigh. Almost always.

Sign of spring: the snow sculptures on the harbourfront have finally melted completely. Ice is out on Kenora Bay.

Just like every year, the lake will melt. Unlike other years, we may not be able to enjoy it much. Until restrictions for the pandemic begin to lift, very few of us will be able to get out there. Even when things start to improve, some form of physical distancing will probably still be necessary. Large gatherings will have to wait. I don’t think we’ll be tying our boats together, or sharing drinks from a common cooler, anytime soon.

Be strong. Be patient. Be healthy.

 

 

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