Great Lakes Water Levels Continue Substantial Drop

Bill's Blog

Sunrise Friday from the Port Sheldon Buoy

The Great Lakes water levels are continuing to drop at a significant rate. That trend will continue into at least early summer. The rivers that empty the Great Lakes still have above average flow, while the rivers that fill the Great Lakes have below average flow. (the pic. above is sunrise from the Port Sheldon buoy. Friday was a very calm day on the lake with the waves at the lake running around 3″ much of the day).

Sunset Friday evening at the Muskegon Channel (5/14/21)

The water level of Lake Superior is unchanged in the last month and down 5″ in the last year. The lake is still 5″ above the May average level.

The level of Lakes Michigan/Huron is also unchanged in the last month, but it’s down 15″ in the last year (that’s a lot!). It’s still 18″ above the May average level.

The level of Lake Erie is up 2″ in the last month, but own 13″ year-to-year. The lake is 14″ above the May average level.

Lake Ontario is down up 5″ in the last month, but down 24″ in the last year (there is a little ability to control the level of Lake Ontario through at dam on the St. Lawrence River). The lake is 11″ BELOW the May average level.

Lake St. Clair is up 2″ in the last month, down 14″ in the last year and still 17″ above the May average level.

Graph of Wave Height at the Port Sheldon buoy

The graph above shows the wave height for the last few days at the Port Sheldon MI buoy. Waves have been mostly under 6″ for the last 3 days. Full sun over the lake will help to (albeit very slowly) warm up the water. The water temp. at the Port Sheldon buoy was just 46°.

Sunrise at the South Haven Channel – look at the fishing boats heading out shortly before 7 am

The rivers that empty the Great Lakes have come down a little, but still have above average flow. The St. Mary’s River at S. Ste. Marie has a flow of 92,300 cfs, compared to an average flow of 71,900 cfs. The Detroit River at Detroit has a flow of 222,000 cfs, compared to an average flow of 202,000 cfs.

In contrast to that, rivers that flow into the Great Lakes have well below average flow. Early Sat. AM, the Grand River in Grand Rapids had a flow of 2,170 cfs, compared to an average flow of 4,720 cfs for 5/15. The St. Joseph River at Niles had a flow of 2,830 cfs, compared to an average flow of 4,150 cfs. The Kalamazoo River at Comstock had a flow of 590 cfs, compared to an average flow of 1,070 cfs and the Muskegon River at Croton had a flow of 1,110 cfs, compared to an average flow of 3,040 cfs.

The Saginaw River at Saginaw had a flow of 2,210 cfs, compared to an average flow of 6,560 cfs.

Across the lake, the Fox River at Appleton WI had a flow of 2,850 cfs, compared to an average flow of 7,220 cfs.

With clear skies, dry air and light winds (Kalamazoo’s average wind speed on Friday was just 1.4 mph midnight-to-midnight), we had some big temperature swings on Friday. Cadillac rose from a low temp. Fri. AM of 30° to an afternoon high of 70° – a rise of 40 degrees. Ditto at Kalamazoo with a low of 34° and a high of 74°. It was much cooler at Lake Michigan during the day and warmer at night. The Muskegon Beach had a high/low of 57°/42° – a difference of only 15°. The South Haven Lighthouse had a high temp. of 59° and a low of 45°. Once again today it will be cooler during the midday/afternoon at Lake Michigan.

Friday PM, the relative humidity dropped to 18% at Kalamazoo and just 17% at Battle Creek. We should see afternoon temperatures into the low 70s over much of West Michigan with a bit more cloud cover than the past few days. The chance of rain is not zero this Saturday, but any showers would be scattered and mostly brief. It will be cooler near Lake Michigan.

We’re done with frost/freeze. In fact, we’re headed into the opposite direction, with highs in the low-mid 70s this weekend and then into the 80s. later this week.

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