Great Lakes Freezes and Lake Effect Snow

[Sbooker]

Try this. If it doesn't work, I don't know what to say. I've been asked not to post full articles as that's apparently poor internet form. A shame as it's an excellent piece with some nice graphics.

Got it. Thanks.
I didn’t know that the Great Lakes froze - even partially. I assumed their sheer volume would prevent that.
I knew about the water/air temperature differential and fetch from reading about lake effect snow (sea effect) in Japan.

 

[Tony Crocker]

I'm getting the same

Would have to create a Free Account to read the WP article.

message. This must be a new thing. I've clicked on James' gift links before and they have worked fine.

I didn’t know that the Great Lakes froze - even partially. I assumed their sheer volume would prevent that.

There's some variation likely based on volume. Even though Erie is the southernmost, it freezes regularly. That's why the huge snowfalls in Buffalo are mostly in December and rarely later in the winter. And Superior has incomplete freezes so that's why Mt. Bohemia gets dumped on all winter.

Japan is on a different level.
1) Temperature differential is greater because Siberia is colder than Canada.
2) Long fetch over salt water that does not freeze.
3) Real mountains with orographic uplift in Japan vs. under 1,000 vertical molehills near the Great Lakes.

Mt. Bohemia which has a perfect location in Great Lakes context gets half as much snow as Niseko.

 

[flyover]

And Superior has incomplete freezes so that's why Mt. Bohemia gets dumped on all winter.

Superior froze to 100% in 96 and has gone well over 90% five times in the last 25 years. That is less frequently than it used to. I remember the lake effect shutting down in 2014 and 2019. Presumably, it also shut down in other years where more than 90% of the lake froze.

From NOAA:

 

[Tony Crocker]

I remember reading about Superior's unusually high freeze in 2014. But I looked up Mt. Bohemia's snowfall and it was the highest of the 18 years on record. December was 2x average while January and February were close to average. That chart shows huge year to year variability.

Bohemia's standard deviation of snowfall is 23% of its average. That is more consistent than most North American ski areas. It is very surprising the lake freeze percents in the chart above are positively (62%) correlated with Bohemia's season snowfall. Perhaps a cold winter is more important to Bohemia's snowfall than how much of Superior is frozen.

 

[Skieric]

I remember reading about Superior's unusually high freeze in 2014. But I looked up Mt. Bohemia's snowfall and it was the highest of the 18 years on record. December was 2x average while January and February were close to average. That chart shows huge year to year variability.

Bohemia's standard deviation of snowfall is 23% of its average. That is more consistent than most North American ski areas. It is very surprising the lake freeze percents in the chart above are positively (62%) correlated with Bohemia's season snowfall. Perhaps a cold winter is more important to Bohemia's snowfall than how much of Superior is frozen.

My knowledge of the great lakes is that Superior generally only gets freezing near shore and always has open water allowing for ongoing lake effects. Therefore the percentage frozen may be more reflective of average temperature. I used to live in Cleveland. Lake Erie is much different. Its very shallow and can completely freeze. When its completely frozen, the lake effect stops.

 

[jamesdeluxe]

Lake Erie is much different. Its very shallow and can completely freeze. When its completely frozen, the lake effect stops.

Yes, Lake Erie is by far the shallowest of the Great Lakes. Here's what a search turns up:

• Lake Superior: the deepest of the Great Lakes, with an average depth of 483 feet (147 meters) and a maximum depth of 1,333 feet (406 meters)
• Lake Michigan: the second largest of the Great Lakes, with an average depth of 279 feet (85 meters) and a maximum depth of 925 feet
• Lake Huron: has an average depth of 195 feet (59 meters)
• Lake Ontario: has an average depth of 284 feet and a maximum depth of 802 feet
• Lake Erie: has an average depth of 62 feet (19 meters) and a maximum depth of roughly 210 feet (64 meters)

It sounds like Lake Superior never gets warm enough to comfortably swim in the summer unless you're wearing a wetsuit.

While living in Chicago 30 years ago, Lake Michigan was almost always tolerable for a dip during the warm months. I was there during the ghastly July 1995 event and going swimming in the lake every half hour was a godsend. I never got over the odd sensation of feeling like you're living next to the ocean in the middle of our continent.

 

[flyover]

I remember reading about Superior's unusually high freeze in 2014. But I looked up Mt. Bohemia's snowfall and it was the highest of the 18 years on record. December was 2x average while January and February were close to average.

Perhaps a cold winter is more important to Bohemia's snowfall than how much of Superior is frozen.

Superior hit its maximum ice coverage on March 6 of that year. Here are the snowfall records for the Keweenaw that winter:

So there was measurable snowfall 20/31 days of January, 20/28 days of February, 11/31 days of March, and 8/30 days in April. January and February had several stretches of many days in a row with some measurable snowfall, consistent with lake effect. March and April not so much. What is interesting is the big dumps on April 4 and 17. In the time-lapse in the post bellow, you can see more fish-bone shaped clouds earlier in the winter. Those are consistent with bands of lake effect on or around Superior.

Yes, in my experience, at least until there's too much ice coverage, the colder the better for lake effect around Superior.

 

[flyover]

My knowledge of the great lakes is that Superior generally only gets freezing near shore and always has open water allowing for ongoing lake effects.

That's somewhat true most winters, but not all. For example, here's the satellite time lapse for 2013-2014 we've been discussing above:

Several winters since I first moved here in the 80s, I've had the experience of standing at an overlook on or around the Superior Hiking Trail hundreds of feet above the lake and seeing ice coverage as far as the eye could see. Also, wolves have historically moved back and forth over the 15 or so miles ice that can form from the lake's north shore to Isle Royale.

 

[flyover]

It sounds like Lake Superior never gets warm enough to comfortably swim in the summer unless you're wearing a wetsuit.

That's never been quite true in late summer in some of the shallower, more protected parts of the lake, like Wisconsin's Apostle Islands.

In other parts of the lake that were historically frigid year round, it has increasingly not been the case that the lake is too cold for tolerable swimming in summer. In the first week of July 2023, we spent several days backpacking around Ontario's Lake Superior Provincial Park and were shocked to find ourselves not immediately jumping out of the water when swimming after a day of hiking. I have a long-time friend who's an EPA limnologist in Duluth. The warmer average surface temperatures are changing the lake.

 

[Sbooker]

Yes, Lake Erie is by far the shallowest of the Great Lakes. Here's what a search turns up:

• Lake Superior: the deepest of the Great Lakes, with an average depth of 483 feet (147 meters) and a maximum depth of 1,333 feet (406 meters)
• Lake Michigan: the second largest of the Great Lakes, with an average depth of 279 feet (85 meters) and a maximum depth of 925 feet
• Lake Huron: has an average depth of 195 feet (59 meters)
• Lake Ontario: has an average depth of 284 feet and a maximum depth of 802 feet
• Lake Erie: has an average depth of 62 feet (19 meters) and a maximum depth of roughly 210 feet (64 meters)

It sounds like Lake Superior never gets warm enough to comfortably swim in the summer unless you're wearing a wetsuit.

While living in Chicago 30 years ago, Lake Michigan was almost always tolerable for a dip during the warm months. I was there during the ghastly July 1995 event and going swimming in the lake every half hour was a godsend. I never got over the odd sensation of feeling like you're living next to the ocean in the middle of our continent.

I just looked at average summer temps. That heatwave was a freak that’s for certain!

 

[Tony Crocker]

That's never been quite true in late summer in some of the shallower, more protected parts of the lake, like Wisconsin's Apostle Islands.

I took a dip after kayaking near Washburn, WI on Labor Day weekend 2020. We were told water was 58F. I suspect Chequamegon Bay is the warmest part of Lake Superior.

 

[Tony Crocker]

Here are the snowfall records for the Keweenaw that winter:

From that same site, monthly averages:
Nov. 23.3
Dec. 61.4
Jan. 67.5
Feb. 55.8
Mar. 22.3
Apr. 21.3

Niseko:
Nov. 41.7
Dec. 136.9
Jan. 147.4
Feb. 104.7
Mar. 53.4
Apr. 5.4

The above demonstrates how the cold air temperatures are the key driver of lake effect snow. At high altitude in the Alps and Colorado, monthly averages November - April are not that different.