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Bill’s Blog: Seiche occurs on Lake Michigan

A seiche occurred on Lake Michigan shortly after noon in Manistee and Mason Counties. The two pictures above (from Tom and Brad Reed Photography) were taken just nine minutes apart.  At 12:18 pm, you can see the breakwater covered in water as a thunderstorm quickly turned the wind from the northeast to the west and back again. 

This is a map of severe weather reports for Friday as of 8 pm.  A thunderstorm formed near the Mississippi River and moved across Wisconsin. The line of green dots going across Wisconsin are the severe hail reports from this storm.  There was hail from the storm in Michigan, but not large enough (1″ in diameter) to rate as severe.

This is the radar image of the storm as it came into Ludington and Manistee.  The red color is heavy rain (and hail).  Often when a storm takes on a curved shape (like a comma) it is an indication of strong winds with the storm.  At the Ludington shore, the wind at 12:12 pm was north at 5 mph.  At 12:18 pm, it was west at 27 mph with a gust to 42 mph.  At 12:24 pm it was back to the north-northeast at 12 mph and at 12:30 pm the wind was northeast at 5 mph.

This graphic is from the Geology Dept. at MSU.  It demostrates the effect the wind has on water.  The west wind pushed the water toward shore.  Then as the wind turns back to the northeast, the water level drops.  Rivers that connect to the lake might see water backing up (reverse flow) for a short time as the water level of Lake Michigan rises, then flow back at a faster rate as the level goes back down. 

This is a trace of the water level at Ludington, showing the level rising as the west wind hits, then sloshing back and forth/up and down like the water in a bathtub might do.  The level went up and down a little over 18″.  The later level of Lake Michigan is already 15″ higher than average, so the additional 18″ caused the breakwater to be totally submerged for a few minutes.

There have been deadly seiches on Lake Michigan.  In 1929, a seiche flooded the Grand Haven pier sweeping people off resulting in 10 deaths. In 1938, a large seiche occurred in Holland, that swept people from the pier and away from the beach resulting in 5 deaths.    On July 4, 2003, there were seven drownings within a three-hour period along a concentrated three mile section of beach near St. Joseph.  

There have been deadly seiches on Lake Michigan.

In 1929, a seiche flooded the Grand Haven, Mich., pier sweeping people off while strong rip currents carried several more away from the beach resulting in 10 deaths. In 1938, a large seiche occurred in Holland, Mich., that swept people from the pier and away from the beach resulting in 5 deaths.

Strong rip currents are often associated with a seiche because of the very dangerous water fluctuations and movements of abnormal currents. Many of the seiches that have taken lives have occurred on Lake Michigan with a few somewhat large and destructive seiches taking place on lakes Superior, Huron and Erie. A series of seven drownings along the southeast shoreline of Lake Michigan on July 4, 2003, were associated with a moderate to strong seiche of the basin. During this single event, seven rip current-related drownings were reported within a three-hour period along a concentrated three mile section of beach.  The drawing here shows a seiche in Chicago in 1954 that resulted in eight fatalities.