An ice shove in Menominee, Mich. on Apr. 13, 2014. (weather.com/photos contributor mike5501)
The photo above is not a pile of snow deposited by dump trucks or snowplows. This is an ice shove in Menominee, Mich. photographed on April 13, 2014.
According to Fox 11 in Green Bay, the ice shove closed the road to the Menominee lighthouse and caused some minor property damage.
Ice shoves were also reported along the western shore of Lake Winnebago in the city of Oshkosh, according to WKOW-TV.
An ice shove is a rapid push of free-floating lake or sea ice onshore by wind. Strong winds from the same direction over, say, a 12 to 24 hour period, are enough to drive large chunks and plates of ice ashore.
The initial slabs or blocks of ice will slow down momentarily when reaching land, creating a traffic jam of ice piling behind and on top. The result is a massive ice pile often over 10 feet high, surging ashore in a matter of minutes, surrounding and damaging everything in their path, including trees, sod, fences, and homes.
In some parts of the Great Lakes, Upper Midwest and Canada, ice shoves are common in the spring as lake ice breaks up, floats, then push ashore. April and May are considered ice shove season along Wisconsin's Lake Winnebago shore.
An impressive string of ice shoves were documented in spring 2013, including a destructive event along the southwest shore of Manitoba's Dauphin Lake on May 10, damaging 27 homes near Ochre Beach.
High-resolution satellite image of Lake Superior and northern Lake Michigan on Apr. 15, 2014. Dark blue indicates areas of open water while ice cover remains widespread over the southern two-thirds of Lake Superior. (NASA/MODIS)
Record April Ice Cover
Ice cover over the Great Lakes as of April 15 is the most widespread on record for mid-April, covering over 39 percent of the Great Lakes.
Satellite monitoring of Great Lakes ice cover began in 1973. The Weather Channel's winter weather expert Tom Niziol (Facebook | Twitter) says only three other years came close to mid-April 2014's ice cover:
- 1979 - 21 percent ice cover
- 1994 - 23 percent ice cover
- 1996 - 21 percent ice cover
Ice is most widespread over Lake Superior, covering 62 percent of the world's largest freshwater lake. Only 21 percent of Lake Michigan remains ice-covered, including much of Green Bay. Lake Huron is 39 percent ice-covered while Lake Erie is just over 23 percent ice-covered, mainly in the lake's eastern half.
In early March, Great Lakes ice cover neared an all-time record, peaking at 92.2 percent.
Given the remaining ice cover, any strong low-pressure systems or cold fronts with a prolonged period of strong onshore winds may push more piles of ice ashore before spring's warmer temperatures finally melt the leftovers from one of the coldest winters in at least two decades.
MORE: Icy Lighthouses
The St. Joseph, Mich. outer light covered with a thick coating of ice on Jan. 26, 2013. (Tom Gill)