The above map from Brian Brettschneider and the NWS shows the probability of a White Thanksgiving. West Michigan is in the 20-40% category. The average high/low temperature for 11/23 in G.R. is 44/31 – still warm enough that most of the precipitation is still rain. This year winter is off to an early start over a large part of the Northern Hemisphere.
This map from the National Snow and Ice Data Center shows snow cover over the U.S. and Canada. 13.1% of the contiguous U.S. had snow on the ground this (Tue) morning. That compares to only 0.3% on this date last year. Almost all of Canada has snow on the ground. Rutgers University has a Snow Lab that has been keeping a record of snow cover for the last 50 years. The latest update showed that this year’s North American snow cover ranks 7th greatest out of those 50 years and for the Northern Hemisphere, snow cover ranks 9th out of the last 50 years. Dr. Judah Cohen (and others) from M.I.T. has done considerable research on the correlation between early snow cover in North America and Eurasia and the severity of the coming winter in the Northern Plains, Great Lakes and Northeast. His latest analysis supports the Storm Team 8 winter forecast of cooler temperatures and above average precipitation.
This is the 6-10 day temperature outlook from the Climate Prediction Center for Nov. 20-24. That’s Monday through Friday of next week, including Thanksgiving. Lower Michigan is “in the blue and that means a higher than normal chance of below average temperatures. The pattern is cool in the East and warm in the West.
Here’s global sea surface water temperature anomaly (difference from average temperature). You can clearly see the La Nina (colder than average water temperatures along the Equator west of South America. Knowing the date and just looking at this map…I’d have to forecast above average precipitation in the Great Lakes over the next several months, with a ridge trying to maintain itself off the SE coast of the U.S. and cold air coming off the snowcover down into the N. Rockies and N. Plains and Great Lakes.