May 7, 2022: Satellite Saturday

We’ve had almost a whole week of sunny weather, so at least one of the NASA satellites got a picture for five days running.

I was hoping to put them together as an animated gif or a slide show, but it didn’t work well.

I’ll just show them in reverse order so you can compare.

If you need help getting oriented, go to the last one, May 3, and click on it. You’ll see a version with some landmarks labelled.

May 7.

May 6.

May 5.

May 4.

May 3.

The amount of progress in five days is impressive. The amount of open water is very different in the first and last pictures. But it’s the steady change in the colour (and strength) of the ice that is most important.

While we’re looking at things from overhead, Tom Lindstrom went cruising by in an airliner today and took a series of pictures from the cockpit. Many of them turned out kind of dark; I think his camera was dazzled by the brightness of the ice. I’ve enhanced the contrast on these two to improve the difference between islands and water, so they look a little odd, and the ice colour is not correct.

You can click on these pictures to see a larger version. Then zoom in, because these pictures are big

Kenora waters.

This picture covers everything from Kenora a the top left, to Second Channel at the bottom right. Zoom in and you can see the last patch of candled ice in Kenora Bay.

From Safety Bay to Bigstone Bay.

This second shot includes a wider area. Bigstone Bay is at the top right, Middle Island and Scotty Island are near the corner, Welcome Channel and Poplar Bay are halfway down the right side, and White Partridge is at the bottom.

The weather:

We hit at least 20°C yesterday, and it’s 22°C as I write this, exceeding both the forecast highs and seasonal averages. But just so you know, the record high for this date is 31.7°, set in 1953!

Now we’re supposed to get a couple of days of rain. Because weekend. But wet weather is not entirely bad. High humidity can have a powerful melting effect on ice. This is due to the energy released when water vapour condenses onto ice or snow. The humidity actually does more damage than the rain.

However, the rainy weather means we won’t get any satellite coverage until Tuesday, and it may not be good enough for my pilot friends to take pictures, either. So we’ll have a bit of an information blackout for a few days. If you go boating, you could use the comments form on the ABOUT page to let us know how you made out, and how far you got.

Signs of Spring:

I finally found time to put my summer tires on today.

Flies are out. Midges will be next, I think, and a friend mentioned that with all this standing water, the mosquitoes may get off to a roaring start this year.

I can’t find a bulletin on a planned date for the removal of the Coney Island pedestrian bridge yet. It gets scheduled for removal when the ice clears out between Kenora and Devil’s Gap, leaving the bridge as the only obstacle to boat traffic. That hasn’t happened yet.

 

May 6, 2022: Fresh Aerials

Justin Martin, my former Chief Pilot, was flying again today and had time to snap a few quick shots.

So here’s the speed tour. You can click on these pictures to see them enlarged.

Looking west over Laurenson’s Lake.

Note that Laurenson’s Lake is still frozen. There is actually a little water at the east end, off the bottom of the picture.

Devil’s Gap and Treaty Island.

Ice is yielding at both the inlet (left) and outlet (right) sides of Devil’s gap now. Open water is spreading into Rat Portage Bay, although Gun Club Island, as usual, is staying iced in a bit longer.

The plane swung left a little to show the Manitou better.

Town Island and the Manitou.

Following Keewatin Channel out to the Manitou is one of the main ways to reach open water from Kenora, and it opens earlier than Devil’s Gap. I think next week Scotty Island will be reachable by boat.

Big Narrows and Wiley Point.

Open water continues to expand all around Big Narrows. Looks like Wiley Point is getting its toes wet now.

The Barrier Islands, seen from the south side.

Justin took several pictures of the Barrier Islands area around the Elbow. I like this one best because you can see how the water is reaching north towards Middle Island and (eventually) town. The big patch of water at the left is the Elbow, and if you zoom in you can see that things are improving at French Narrows on the right.

Now that the ice is turning grey, the pressure ridges really stand out.

Thanks Justin!

Another sunny day, another MODIS shot. I think Aqua got better light quality than Terra today.

MODIS image of Lake of the Woods from Aqua satellite, May 6, 2022, in false colour.

Open water continues to expand, and ice is softening all over the lake. It looks as if shorelines may be letting go, especially in the south half of the lake.

Signs of Spring:

On Kenora Bay, the ice is completely candled now. It will be gone very soon.

Motorcycles. I saw three today, and just heard another. Remember, riders need to avoid both potholes and patches of loose sand. Give them room in case they have to brake or evade.

Ticks. Found my first tick today, on my belly after walking Ebony. Yay.

Ebony gets refreshed after overheating.

No ticks on her, though, we checked. This is important because of Lyme Disease, which took the life of Piper, our previous dog. There’s a now a new option in tick preventative pills. Ask your vet.

May 6, 2022: Forecast Friday

First off, I made mistakes with the previous post. Dated May 5, I forgot to hit the PUBLISH button until this morning. Secondly, the version that went out by email was incomplete. A drone panorama from Paul Leischow was omitted from the version I hastily put out, and the email version will not be updated to show the corrected version.

To see the full May 5 post, click here or visit the Ice Patrol home page and scroll down.

Now, on to the latest. Sean has been tracking how the weather we’re actually getting compares to the weather forecasts he bases his predictions on. You may recall that we put more trust in the seven day weather forecast than the fourteen day outlook.

This time around, that has worked out well. In the week since Sean released his first prediction, the weather was very close to what was forecast. The second week of that fourteen day outlook is now our coming week, and the new seven day forecast for it is more optimistic.

To be clear, the weather forecasts are updated all the time, and new seven and fourteen day forecasts come out every day. But because Sean does his graph on one particular day, the forecast line on the graph reflects the forecast available at that time.

Sean has revised his graph with the new information, and with more confidence.

Remember, you can click on this graph to see a larger version. You should zoom in on that to see it at it’s largest and sharpest.

If you want to refresh your memory, you can see the previous version by clicking here.

So, what’s different? The blue line is steeper. That’s good. It means that the weather forecast is better, and that means we’re likely to hit the target thaw index sooner. Sean is now saying it looks like the ice will be gone a day or two before the May long weekend, instead of just as it begins.

Graph Explanation:

The horizontal yellow line represents the thaw index we think we’ll need to reach to melt all the ice on the lake.

The blue line represents our thaw index this year, based on known temperatures so far, and forecast temperatures for the future.

The red line shows how fast the cumulative temperatures can rise in a very good year. It’s based on the fastest-warming spring in our records.

The green line represents a worst-case scenario based on the weakest, coolest spring we know of.

It’s worth noting that the revised graph now shows that our weather is tracking very close to the best-case scenario, roughly paralleling it. That would give us a thaw that’s very fast. That’s about right for one that happens this late in the year.

Now the fine print.

This graph and prediction is based solely on air temperatures and an assumed thickness of ice based on the winter’s severity. It does not take into account such factors as the strength of water currents, precipitation, humidity, the UV index, tornadoes, tsunamis, or comet impacts.

This graph may pose a choking hazard to pets and small children, especially on a smartphone. Wear sunblock if reading the graph outdoors. Do not attempt to use this graph while driving or operating heavy equipment. Follow regional and local safety regulations regarding eye protection and personal safety equipment. Always unplug the graph before putting your hands near the moving parts.

 

 

 

May 5, 2022: Overview

So far this week, we’ve been looking at the lake one patch at a time. This morning, Jonathan O’Connor was aboard Air Canada’s flight AC259 from Toronto to Winnipeg. He sent in some photos.

Yes, you can click on these to see a larger version that you can zoom in on.

We’ll go from east to west, like Jonathan’s flight.

Whitefish Bay and Long Bay.

This is Whitefish Bay, and at the right of the photo is Highway 71. Don’t be fooled by the powerline, which is straighter and more obvious. The road is closer to the right edge, and much wigglier. Zoom in and you can see the open water at the  Sioux Narrows bridge. Because the camera is pointed down for this shot, it provides a good look at the condition of the ice, which looks soft.

Here’s his view of the northern part of Lake of the Woods.

North of the Alneau Peninsula.

In the foreground is the Alneau Peninsula. The Barrier Islands stretch across the middle of the frame, and if you look closely, you can see the big patch of open water at the Elbow. Above the middle to the right are Hay Island, Bigstone Bay and Longbow Lake. Towards the upper left, the water in Keewatin Channel is hard to distinguish from the land unless you zoom in. From high altitudes, the haze tends to make trees and water look a similar shade of blue, especially in the distance.

Big Narrows.

As the plane travelled west, Jonathan captured this view of Big Narrows that also shows Ptarmigan in the distance.

Thanks, Jonathan!

The continuing clear weather means there are new satellite images every day. I’ll put together a look at the whole week on Satellite Saturday, but in the meantime, here’s today’s shot from Terra.

MODIS image of Lake of the Woods from Terra satellite, May 5, 2022, in false colour.

We also have a new drone Panorama from Paul Leischow.

As usual, clicking on the still image below will take you to a panorama that you can watch, or use your mouse to interact with.

Drone view of Keewatin Channel.

It’s worth mentioning that at this time of year, this whole area would usually be all open water, with lots of boat traffic.

Thanks, Paul!

Two things are happening on Friday: Sean will reveal how the actual weather and the changes to the weather forecast affect his graphs predicting the likely timing of ice-out.

I’ll be live on Q-104 with Ken O’Neil at 7:50am to talk about that, and how the sudden arrival of spring weather is changing things.

May 4, 2022: Startling Change

I had a chance to go flying today. Quinn Wilson, one of my former colleagues, was able to take me for a flight in one of MAG Canada’s Rockwell Aero Commander 500s.

We went for a tour of the northern half of the lake. I took quite a lot of pictures, and here’s a selection of the most informative.

You can click on these photos to see a larger, zoomable version.

Rat Portage Bay and Safety Bay.

The usual shot taken shortly after take-off. At the left edge, Rat Portage Bay is showing an increased amount of open water; it approaches Gun Club Island now.

We flew west to check out Clearwater Bay.

Clearwater Bay and Deception Bay.

Most of Clearwater and Ptarmigan are still frozen over.

Deception Bay.

But there is some open water around the marina in Deception Bay.

Ash Rapids.

I wanted a closer look at Ash Rapids to see if there was more open water than yesterday. I think yes, a little.

Southwest end of Big Narrows.

Big Narrows is practically wide open now. Of course, the routes to it are still frozen.

Wiley Point.

From Big Narrows, the open water has spread as far as Wiley Point.

From there, we cruised over to look at the Barrier Islands.

Crow Rock Pass.

Spotted some open water at Crow Rock Pass, and there’s a tiny bit near Twelve Mile Portage, too.

The Elbow.

Developments around the Elbow look more dramatic. I’m sure there’s more open water here than in Justin’s pictures from just thirty hours earlier.

Queer Island and French Narrows.

And where we saw weakening ice yesterday, there are growing patches of open water around Queer Island.

Next, over to Bigstone Bay.

Eagle Pass.

There’s still just a very small patch of water at Eagle Pass.

Scotty Island, Nanton Island, Town Island.

I’m keeping a close eye on the waters approaching Scotty Island, as this is an area of dynamic change. I think there’s a visible difference since yesterday.

Lastly, a look at Devil’s gap from the Rogers Island side.

Rogers Island and Devil’s Gap.

Ice in this area always holds out longer than you’d expect. In fact, this very spot was the reason Ice Patrol started in the first place,  But there is noticeable change here, too, as the water opens up towards Galt Island.

I hope to go flying with Quinn again in a few days. Thanks, Quinn!

In summary, there was a surprising amount of change in one day. Patches of rotten ice opened up dramatically, and most areas with open water saw at least a little expansion.

The latest MODIS image bears that out.

MODIS image of Lake of the Woods from Aqua satellite, May 4, 2022, in false colour.

Here’s the matching shot from yesterday.

MODIS image of Lake of the Woods from Terra satellite, May 3, 2022, in false colour.

Black patches of open water seem larger in today’s image. Although the lake is still about 95% ice-covered, whole swaths of that ice have turned darker, indicating that it is thinning or weakening.

The weather: tomorrow we might see above normal temperatures for the first time in weeks. The Weather Network says a high of 16°C, slightly above seasonal norms of around 15. Environment Canada thinks we might make it to 18°C. Friday’s supposed to be similar, but the weather will be a few degrees cooler on the weekend, and rain is expected to start on Saturday night and last a few days. I was recently reminded by retired meteorologist Louis Legal, that it’s not the actual rain that destroys ice. It’s the high humidity that comes with the rain, and the energy transferred when water vapour condenses onto snow or ice. So I expect rapid change for the next few days. We could be approaching a turning point.

The Lake of the Woods Control Board has announced that the Norman Dam will soon be going wide open. You can read the full announcement at the preceding link, but the gist of it is that there was record precipitation in April, so the lake has been rising fast and will continue to do so. The lake is already at 95th percentile levels, and it is predicted to reach the highest allowable levels by mid-May. Even at maximum flow, the dam cannot drain the lake as fast as it is filling up, so the dam will be opening all the way on May 7, in an attempt to get a head start.

Signs of spring: Loons are back. I thought I spotted some yesterday, but today I was able to confirm it with Derek, an experienced birder who has seen and heard them clearly. Oh, I guess that’s another sign of spring: the birders must be getting more active, because I met two today. On a more urban level, the street-sweepers are out. This also sparks joy, but in a less poetic way.

May 3, 2022: Signs of Progress

Well okay. The thaw has finally started.

Thanks to the wet weather, the snow in town is mostly gone. Some of the larger snowbanks persist, but streets and sidewalks are basically dry.

So what about the lake? Justin Martin was out flying at around midday today, and sent me some pictures.

You can click on these photographs to see a larger, zoomable version.

We’ll start the tour at Northern Harbour on Pine Portage Bay.

Pine Portage Bay, looking west over Bald Indian Bay.

The docks at Northern Harbour are at the lower right corner of the picture, and they’re completely ice-locked.

The next picture moves forwards and swings a little to the left to show Scotty Island and Middle Island.

In an Ice Patrol post almost a week ago, there were signs of weak ice to the south of Keewatin Channel. Wet weather since then should have made a difference. And it has.

Needle Point, the northern tip of Hay Island, is in the foreground. Behind it are Middle Island and Scotty Island. To the right are Nanton’s Island and Lunny’s Island, and Town Island is at the right edge.

Now we can see open water extending past Town Island, and reaching as close to Scotty Island as Anchor Island.

Time to check on the Barrier Islands.

Looking west over Square Island at the Barrier Islands.

The most notable thing in this view is the large patch of open water at The Elbow.  There’s more water at Queer Island, and I think that’s a new development. At the left of the picture, French Narrows isn’t showing much change yet, but all the ice in the foreground looks soft.

There’s progress down at Big Narrows, too.

Tranquil Channel and Big Narrows.

Lots of water here. Donald Duck Island is at the lower right, and this view makes it obvious how it got its name. The ice in this area looks fairly sound.

Next up, Ptarmigan Bay.

Ptarmigan Bay, with Clearwater and Deception in the distance.

The photo above shows most of Ptarmigan Bay and Clearwater Bay. By and large, it’s all frozen.

There’s one exception.

Open water at Ash Rapids.

That’s our round-up for today. Thanks, Justin!

Generally speaking, the ice is softening in areas with current, and areas of open water are expanding slowly.

Warmer weather is on the way, so we can hope for more progress in the days to come.

Today’s clear skies meant that Terra got a good look at us.

If you click on this satellite image, you’ll see a version with some landmarks tagged.

MODIS image of Lake of the Woods from Terra satellite, May 3, 2022, in false colour.

There are more patches of black, representing open water, and the land seems to have a lot less snow.

Here’s how it looked one week ago, if you want to see the change.

MODIS image of Lake of the Woods from Aqua satellite, April 26, 2022, in false colour.

Seeing the images together also reveals how the quality of the ice has changed in a week. Notice how much darker the ice looks in the upper image. That indicates that it has grown weaker.

It’s not very helpful to look back on May 3rd of previous years. Often the lake was open by now, or nearly so. The one year that would be worth a look was 2014, another notoriously late year. I checked the archives at the University of Wisconsin at Madison’s website, and the pictures from early May of 2014 are mostly cloudy. From what I can see, the lake looked about the same. That year, Lake of the Woods wasn’t ice-free until May 21.

Signs of spring: the pelicans are back.

I think it’s time to mount my summer tires. We might actually see temperatures as high as 16°C this week. That’s a whole degree above average.

May 1, 2022: Snakes & Ladders

It’s raining out. Let’s play a board game. The Ice Patrol edition of Snakes & Ladders, to be specific. I was going to play it straight and call call this post Other Factors, but I’m bored.

Miss Frazzel’s kindergarten class has 20 students. Their names, co-incidentally, correspond to the years of this century, except One and Two missed class today.* The rest of us, Three through Twenty-two, want to go outside for recess, but it’s not nice out, so Miss Frazzel sets us all to playing Snakes & Ladders to pass the time. As the weather improves, she announces that as each student finishes, they can go outside to play. We are Twenty-two, and we haven’t had the best luck. It took us forever to roll doubles and get started. Miss Frazzel calls this the Inflection Rule. We’re on the board now, but we’re way behind most of the other kids.

*She’s named after frazzel ice. No relation to that other teacher with the weird bus.

We don’t have ice-out dates for 2001 or 2002, so those kids don’t get to play our game.

The Ice Patrol S&L board has 42 squares, arranged like a calendar of six weeks. With average rolls of around seven, the kids can reach the Ice-Free finish line in about that number of turns, like a typical thaw lasting six weeks. The dice are the weekly temperatures. Roll some hot weather and you can finish faster. Roll low temperatures and it’s going to take a while.

There are some special squares with writing on them:

Cold Snap: Lose a turn.     Heat Wave: roll again.

Then there are the ladders. Land on The Ice Was Thin This Winter, and you shoot ahead by a whole week. There’s one called Timely Rain that gets you ahead by a few days, and one near the end called Warm South Wind that gives you a four-day boost.

And of course there are the Snakes. Late Snowstorm sets you back five days. We hit that one twice. We were afraid we were going to land on Sluggish Currents, but we dodged that one.

At this point, over a third of the class has already gone out to play in the puddles, and of the thirteen still playing, almost all are somewhere  ahead of us with about two weeks to go. We, and Fourteen, are still only about halfway there.

If we roll average temperatures, we’re looking at three weeks to go. Can we speed it up?  We just hit Timely Rain, and Improving Forecast is coming up in a few squares: we might get a boost from slightly better than normal temperatures after all.

The thing is, we don’t know how it’ll play out yet. Let’s hope the dice are hot.

This whimsical post was inspired by all the different factors that play into the spring thaw. Things like snow cover are important, but are probably more complex than yes or no. Other ideas that have been floated around lately include factoring in the UV index and even allowing for a kind of depreciation of old ice in middling temperatures. To model all these things–or even most of them–we’d need fancy computers and software like the meteorologists have.

And a ton more data. A recent comment from Todd suggested that our early winter snowfalls insulated the ice from the worst effects of the extreme cold in January and February. He measured only 34″ of ice, when he’s often seen 40″ or more. He didn’t say when or where. Update from Todd: this was March 25, and down around Morson.   My regular ice-fishing friends pulled off the lake early due to slush, so they never gave me a late-season measurement from when the ice is thickest. Sean’s ice auger broke down, so he didn’t get a measurement after mid-winter, either. If the ice was not as thick as the winter temperatures suggest, things could go faster than we expected. If you were drilling through the ice this spring, and you can remember the date and location, let me know what you found.

Signs of spring: I’ve seen and heard quite a few songbirds lately. There is still some snow on the ground, but the recent rain has reduced it drastically.

I hiked down to have a look at the Norman Dam today, and the water is gushing through every gate.

Downstream side of the Norman Dam, May 1, 2022.

White water is surging and roiling downstream as far as the hazard buoys. I stayed in the bush, a long way from the slippery wet rocks at the river’s edge.

 

April 30, 2022: Satellite Saturday

Well, it’s raining again. We’re setting records for April precipitation as I write this.

That means the last couple of days haven’t been good for satellite photos, but we got an exceptionally good look at the lake on Wednesday. Sentinel 2 is a European Space Agency satellite that takes high resolution pictures. It doesn’t come our way every day, and when it does, it often images only part of the lake because of it’s narrow field of view.

But on Wednesday, everything aligned.

You can click on these pictures to see them at higher resolution!

Sentinel 2 image of Lake of the Woods, in true colour.

Yes, that’s a colour photo. There’s just not a lot of green in our landscape yet.

But if you’d like something a bit more vibrant, Sentinel 2 also offers a short-wave infrared option.

Sentinel 2 image of Lake of the Woods, in short-wave infrared.

Note the scale (5km) in the bottom right corner. But wait, there’s more good news. This satellite can show more detail than this. I can’t upload a picture of the whole lake at the highest resolution; the file is too big. But I can zoom in for a better look at the north part of the lake, and upload that.

Don’t forget to click on these images to see the full-screen version. Click on that to see the picture’s full resolution.

Sentinel 2 image of the northern part of Lake of the Woods in short-wave infrared.

So on this image, I thought I noticed something. In a recent aerial photo from Tom Hutton, taken the same day, you could see rotten ice south of the Keewatin Channel, extending past Town Island towards Scotty.

Let’s zoom in even tighter on that area, to a 1km scale.

Sentinel 2 image of the Wendigo and Bigstone Bay in short-wave infrared.

Now we can clearly see the dark blotches of softening ice, extending from the open water in Keewatin Channel and Second Channel at the upper left, towards Scotty Island near the middle of the frame.

This is the ice that I expect to yield next.

It’s also worth noting that there are multiple tiny patches of water visible in the vicinity of Middle Island, at Eagle Pass at the east end of Hay Island, and near Railroad Island, south of Hay.

Rapidly rising lake levels, and more importantly, the increasing outflows through the Norman Dam* that the rising water necessitates, should help to erode more ice, starting in these areas with significant currents.

*The Lake of the Woods Control Board strives to keep the lake levels within specified limits. A month ago, the lake was pretty low. Multiple Colorado lows have dumped a lot of first snow, and then rain in the lake’s drainage basin. The board reports that the average lake level has been rising by over an inch a day, (25cm in a week) and will continue at close to that rate for several more days. In the meantime, outflow through the dam has gone from 450 cubic metres per second three weeks ago to more than double that, at 925. Fun fact: a cubic metre of fresh water masses one tonne.

So enjoy the rain!

April 29, 2022: Sean’s Graphs

I know people have been waiting for Sean Cockrem’s graphs. Now that we’ve finally seen temperatures shift to mostly above freezing, he was able to set yesterday as Inflection Date, and start work on predicting how long the thaw might take.

Sean writes:

At long last Iast, I’m ready to declare [April 27th] as the 2022 inflection date. Usually I wait a few days after to make sure that the measured daily means are above zero, but based on how far into April we are and with the 14 day having consistent warm temperatures, I’m going to make the executive decision for this declaration.

This was the third coldest winter so far this millenium. Only the 2013/14 and 2008/09 winters were colder. This was also the latest inflection date we have had in the last 20 years of data collection.

For the forecast, I have set our target thawing index at 190 which is based on an average 1:10 thawing index:freezing index. I’ve entered the forecast data for the next month or so. Keep in mind everything after a week is a guess, and everything after two weeks is based on seasonal temperatures. This year has been anything but seasonal. Having said all that, there is a glimmer of hope that we will be ‘Ice Out’ right around May 20th, which is the Friday of the long weekend. If the temperatures stay below seasonal, it’s going to be a long shot for complete ice out, which is not to say that a good portion of the lake will be open by then.

As far as the season goes, this one will be down to the wire for the next 3 weeks closing in on the long weekend. A bit more interesting on our end than other winters where the ice is off in late April. Fingers crossed we get some sunny warm days.

 

I recommend clicking on these graphs to see a larger version. Then you should click on that to see the graph enlarged to it’s full resolution.

Let’s start with the updated shark-fin graph.

The Shark-fin graph plots the severity of each winter and marks the beginning and end of each thaw.

The key points to keep in mind:

The downward spikes plot the temperature trend of the winter. A long winter makes a wider spike, and a severe winter makes a deeper spike.

The thaw commences when the Mean Daily Temperature rises above freezing (on a lasting basis) and that date is marked with a blue X. This is the Inflection Date.

The thaw ends when the lake is entirely ice free. That date–when we reach it–is marked with a red dot.

What can we tell about the winter we just had? It was the second coldest on the graph, and as Sean said, this is the latest Inflection Date we’ve seen since we started keeping records. (2003 was the year I started taking pictures, so Sean hunted down the weather data back to that year. Before that, we don’t know when the ice was gone.)

Summary: It was a long cold winter, so we assume thick ice. It was a late start to the thaw, so that puts us behind.

On to the next graph.

The Cumulative Freezing Index compares the temperature path of each winter.

This graph takes some of the same data, but focuses strictly on the winter. Each winter’s Cumulative Freezing Index is shown as a separate line that ends on the Inflection Date, and this past winter is represented by the heavy dashed line.

Key points:

The years are synchronized to the calendar on this graph, so some years have already become colder than others at the starting line of December 1st.

We had a mild fall, so we got off to a good start.

This years line drops lower than most, because we had a lot of cold weather.

It extends further to the right than any other line because it took so long to get to Inflection.

Now comes the speculative graph: the Forecast.

This one takes some explaining. In the first two graphs, we gave the winter a “score”.

The Cumulative Freezing Index is a single number that sums up how much cold weather we had over the course of the winter. This winter’s number was -1887.* That’s nasty.

*Refresher: Sean derives this number by using a simple technique. Once the Mean Daily Temperature drops below freezing in the autumn, he takes note of it every day. If the MDT is -3°C one day, the line drops three points. If the MDT is -5°C the next day, the line drops a further five points.

Sean tracks the rising temperatures after Inflection Day, too. Then, using my dates for ice-out, he looked for a relationship between the freezing index and the thawing index. This got him a rule of thumb: for every ten points on the freezing index, you need one point on the thawing index to get rid of the ice.* That’s a starting point.

There are other factors that can hasten or delay the thaw. Sunshine is always helpful. Rain and wind can speed the thaw along, especially if the timing is right.  Strong currents are a plus. On the negative side, snow is the worst, but clear nights and cloudy days don’t help either. This forecast doesn’t try to predict any of those things. They’ll be wild cards that may mess with this simple prediction, or they might balance out.

*does that seem strangely unbalanced to you? For the purposes of Ice Patrol, there are only two seasons: the one where it’s below freezing, and the one where it’s above. Generally speaking, we have more summer than winter here: the summer spikes on the shark-fin graph are bigger than the winter ones. But the thaw is just a few weeks out of the year. If the thawing index had to equal the freezing index to melt the ice, it would take nearly all summer to thaw the lake. Also, the lake is not frozen to the bottom, because water is weird stuff, but that’s a whole other story.

In any case, this forecast is an estimate. Sean figures that we’ll need to accumulate roughly 190 points to get rid of the amount of ice this winter should have created.

So he goes to the weather forecast to see how long that might take, and you know how those are. As Sean suggested above, the seven day forecast is broadly reliable. (When it’s off, it’s usually in the timing.) After that, the fourteen day forecast is more of an educated guess, and the really long-term stuff basically just goes, “I don’t know… normal, I guess?”

The forecast graph tracks how long it might take for the weather to melt the ice.

So here’s how it looks for now. The horizontal yellow line is set at 190 points. That’s our target. The vertical grey line is the start of the May Long Weekend. That’s not a deadline, it’s more of a  wish. The smooth blue line is the weather forecast. It hits the target on Friday of the May Long.

There are two other lines. The red one shows how the Thawing Index racked up in the best year, and the green one represents the worst spring we know of.

The red line is the easier one to understand. 2007 was a lovely spring. If we could have those sorts of temperatures this year, the thaw would go a little faster. But as far as our records go, that’s a best-case scenario, and a long shot.

The green line is confusing. 2004 was a dreadful spring, and in fact the whole summer was exceptionally cool. The temperature trend that spring was feeble. So how did the thaw go? Not bad. It had been a middling kind of winter (~1500 points), so the target that year was lower. Despite the chilly spring, the lake was clear of ice by mid-May, significantly better than the ten-to-one rule of thumb would have predicted. In terms of modelling, 2004’s data made it an outlier.

In conclusion: Lake of the Woods is on track to be clear of ice right around the long weekend. If the weather forecast is right, and if the rule of thumb holds true this year.

Thanks, Sean!

Keep in mind that we should see steady progress between now and then. Marinas will open. Many islands will be accessible a week or more before the lake is entirely ice-free. That may also be true of Falcon Lake and West Hawk.

Shoal Lake plays by it’s own rules, and often lags a few days behind Lake of the Woods.

Further north, the long weekend and the opening of fishing season may face problems.

April 28, 2022: Aerial Photos

My old friend Tom Hutton went flying on over the lake yesterday, and took a whole set of pictures for us.

You can still count the open patches of water on Lake of the Woods on your fingers, but let’s go have a look at some of them.

You can click on these pictures to see a larger, zoomable version.

Kenora, with Rat Portage Bay in the middle and Safety Bay to the right.

Okay, everybody in town knows there’s open water on Safety Bay.

Here’s a closer look at what’s open in Keewatin Channel and Second Channel.

Keewatin Channel and Second Channel. White Partridge Bay in the distance.

We’ve covered this key area in more detail with Paul Leischow’s drone panoramas, but here’s an overview that puts it in perspective.

What about further south than this. Is the ice letting go around Town Island yet?

Town Island at the lower right, Thompson Island in the middle and Wolf Island up and to the left.

It’s starting to look pretty rotten here, where the current flows into Keewatin Channel. But there’s still a whole lot of snow-covered ice out in the Manitou, and well, everywhere. That’s Shoal Lake way off in the distance.

Now a look at the Barrier Islands, because this is the next closest place to Kenora where we can expect to see open water in the early stages of the thaw.

Looking West from the Eastern Peninsula along the Barrier Islands. Square Island* is at the lower right.

There’s a fair-sized expanse of water at the Elbow. French Narrows, at the western tip of the Eastern Peninsula has just a tiny patch. You’ll have to zoom in to see it well. It’s just left of centre in this picture.

*Square Island is not square in shape. It is shaped like a carpenter’s square.

How about down at the south end of the lake?

Looking south from near the Northwest Angle. Birch Island, Oak Island and Flag Island span the picture at the edge of the Big Traverse.

Big Traverse is still ice-covered, but the photo above shows quite a lot of open water along the west side of Falcon Island.

Big Narrows is always worth checking on.

Looking east over Big Narrows.

We saw some low-altitude views of this area from Scott Benson yesterday. In some of those pictures, the slanting evening light made some of the ice resemble water. Here’s how it looks from a higher viewpoint, and the daylight makes the extent of the water very clear.

Lastly, as Tom headed back towards the airport, he took a look at Devil’s Gap.

Devil’s Gap.

This wasn’t clearly visible in the first photo, but you can see that there’s only small penetration of water into Rat Portage Bay, and everything out towards Bigstone Bay is pretty solid.

Thanks, Tom!

Signs of spring: pre-season training for the water-bomber pilots.

Tanker practicing on Safety bay, as seen from Norman Beach.

You might recall that a recent photo showed no open water on Wabigoon Lake, close to Dryden’s big Ontario Ministry of Natural Resources base. Every spring, tanker crews come to Kenora to train on either Safety Bay or the Winnipeg River.