Storm Chasing in Upper Michigan

Bill’s Blog

Posted: Sep 25, 2020 / 05:07 AM EDT Updated: Sep 25, 2020 / 08:03 PM EDT

A Severe Thunderstorm Watch is in effect for western Upper Michigan until 1 am. The Storm Prediction Center says: “Primary threats include…Isolated very large hail to 2 inches in diameter possible…Isolated damaging wind gusts to 70 mph possible …A tornado or two possible.”

Click for latest Composite Reflectivity radar image from the Marquette, MI radar and current weather warnings
Marquette Radar

Here’s Marquette radar (above) and Duluth radar (below):

Click for latest Composite Reflectivity radar image from the Duluth, MN radar and current weather warnings
Duluth Radar

Here’s video of a waterspout that moved onshore and became a brief tornado at Myrtle Beach, South Carolina.

Severe Weather Outlook Area for Sunday 9/26

The Severe Weather Outlook Area for Sunday is much the same, with a Slight Risk across N Wisconsin, surrounded by a Marginal Risk through much of Southern Upper Michigan. SPC says: “Threat will exist for a few strong to severe thunderstorms mainly over a portion of northern Wisconsin late Saturday afternoon into the evening. Primary threat will be large hail, but a tornado or two cannot be ruled out.”

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Storm Reports in Michigan for 2020 through 9.25

The map above shows storm reports so far in 2020 in Michigan. Each red dot is where there was a tornado. Each green dot is for a severe hail report (1″ in diameter or greater). Each blue dot is a severe wind report (damage or a gust to +58 mph). There have only been 2 (small) tornadoes in Michigan this year, both in the U.P. There have been 55 reports of severe hail and 285 reports of wind damage. There has been no severe weather in the the eastern U.P. this year. Same for several counties in Lower Michigan (Antrim, Alcona, Leelanau). The year’s not over, but it’s generally been a “quiet” year in West Michigan.

Two areas that did get severe weather in August were the Southwest corner of Lower Michigan on August 10 from the derecho that moved from Iowa across Illinois and into S. Michigan and N. Indiana and the high winds that hit Cedar Springs on Friday evening August 28.

Stronger Winds over the Weekend

First, there are Small Craft Advisories for lakeshore areas north of Grand Haven for this afternoon and tonight for waves from 2-4 feet. Winds will also crank up a bit from Saturday PM – Sunday and for next Tuesday-Thursday.

Grand River near Eastmanville

This beautiful pic. is the Grand River near Eastmanville from John Steinhauer. It’s been a sunny, warm and generally calm week. Over the last 6 days, the average wind speed in Kalamazoo has been just 3.5 mph. Grand Rapids has had no measurable rain in the last 11 days and only 0.08″ in the last 15 days. We’ve had 5 days in a row with afternoon temperatures in the 70s. Over the last 10 days, we’ve had 84% sunshine!

The cool air will be delayed a bit, with temperatures remaining on the mild side through Sunday PM. The cool air does get here the middle of next week, when daytime temperatures could hold only in the 50s.

8-14 day temperature outlook

Once the cool air gets here, it’ll be ticking around. The models been both insistent and consistent that temperatures will remain cooler than average through the first week of October in the eastern half of the country.