As of this (Fri.) afternoon, ice cover on Lake Superior is at 84.0%. With another Arctic blast on the way for early next week, there is a chance that Lake Superior will totally freeze over for only the second time in the 47-year record of Great Lakes ice extent. The only time that ice cover reached 100% of the biggest Great Lake was in March of 1996.
The only other Great Lake that has reached 100% ice cover since 1973 is Lake Erie. That’s happened three times, in the cold winters of 1978 and 1979 and again in 1996. Even though Lake Erie is the southernmost of the Great Lakes, it often gets the highest percentage of ice cover, because it’s the shallowest of the Great Lakes (average depth 62 ft. and greatest depth 210 ft.).
Great Lakes ice cover is now up to 74.0%. This is the 4th time in the last 6 years that Great Lakes ice has exceeded the average greatest extent of 55%.
You can see that winters with above and below average ice cover often come in pairs or several years in a row (you can see the cold winters of the late 1970s and 2014-15 and the mild winters starting with the strong El Nino of 1998).
The cold air coming across Lake Superior has produced some very heavy season snowfalls in Upper Michigan. Tamarack leads this list with 307.4″ of snow so far this winter. Marquette has 48″ of snow on the ground and they are 52.1″ above average snowfall-to-date. With the lake now mostly frozen over, this is virtually stopped the lake-effect snow, the lake-effect clouds and the lake-effect warming.
The 6-10 day temperature outlook from the Climate Prediction Center for March 6-10 shows a high probability of colder to much colder than average temperatures over the Great Lakes and most of the contiguous U.S.