April 3, 2024: Satellite Images

Two satellites captured nice images of Lake of the Woods lately.

I’ll start with NASA’s Aqua satellite. Both Aqua and Terra should pass within range of Lake of the Woods every day, but the satellites are old, and Terra‘s orbit is not optimal any more. There were no images from either of them over the Easter weekend, but Aqua got a good shot today.

Usually, I just include the little corner of the image that shows Lake of the Woods, but I’ll show a bit more of the big picture today. You can click on this image to see it full size.

MODIS image of the Midwest from Aqua satellite, April 03, 2024, in false colour.

The MODIS satellites actually cover a lot of ground. The little red square in the upper left corner is the portion of the image that shows Lake of the Woods, and I usually crop the picture to just show that part. I included more today because it shows all the Minnesota lakes are thawed except for Red Lake, the pair of oval lakes south of Lake of the Woods. They’re in the process of letting go, and they’re less than a hundred miles south, so spring is on the way.  The other feature in this image is that huge storm spawning wintry weather across the midwest. That looks like the eye of the storm in the lower right corner.

Sentinel 2 also got a good shot of our lake on April first, so here’s a closer look. Sentinel doesn’t have the broad coverage of Aqua and Terra, but it has much higher resolution. The Short-wave Infrared image is comparable to the MODIS false-colour depiction, with strong ice showing as pale blue, weak ice as darker, and open water as black.

Sentinel 2 image of Lake of the Woods on April 1, 2024 in SWIR.

There’s scattered cloud in the north half of this image, but you can clearly see the open water in Keewatin Channel and Second Channel, just south of where it says Kenora. We made some fresh ice in the final part of March, and added some snow cover, too. That’s disappointing compared to some years when the thaw was well underway by this date.

So let’s talk about the weather.

The other day, The Weather Network put up a 14 day forecast that showed some very warm temperatures for the middle of April. I kind of thought that might change, so I made sure to grab a screen shot.

Kenora’s 14 day outlook from April 1st.

The forecast has now been revised. Sharply.

Kenora’s 14 day outlook from April 3rd.

Notice that in the first graph, the top of the scale is 28ºC, but in the second graph, it tops out at just 14ºC. Although they’ve downgraded the forecast for the latter part of the period, they’ve actually raised some of  their predicted temperatures in the short term, and they trimmed four degrees off the bottom of the graph as well.

I think the revised forecast is more believable.

I heard from Sean Cockrem today, the guy who puts together graphs for Ice Patrol, and he thinks we may have hit the Inflection Point. That’s when we start spending more time above freezing than below. Of course, weather can change unexpectedly, so we won’t be sure for a few more days.

Sean uses the inflection date to mark the change from making ice to thawing ice, and works out his predictions from that timing.  He’s the first to admit that there are a lot more variables than simply warming temperatures, but it’s a starting point. I’m looking forward to seeing a graph that shows how this winter stacks up against previous ones.