Winter is over! Forecasters reveal Great Lakes are FINALLY ice free after record breaking seven months frozen
It has been a long, cold winter for much of America - but the Great Lakes have really suffered.
Forecasters finally revealed today that all of the Great Lakes including Lake Superior are now ice free.
It marks the end of a record breaking 7 month stretch where the lakes were covered in at least one ice cube, which is the longest period since satellite records began back in the 70’s.
June 7th became the official ice out date of the lake which also makes in the latest in the year ice has coated the water.
There was still a third of the Lakes coated in ice the last week of April which was the largest amount of ice that late in the year, a trend that continued into June.
Earlier this year Nasa revealed that even though North America was a full month into astronomical spring, the Great Lakes have been slow to give up on the harsh winter.
The space agency published this stunning picture of the Great Lakes, showing a third of their expanse is still covered in ice.
Lake Superior was found to be the most affected, and was found to be 63.5 percent ice covered on April 20th.
Averaged across Lake Superior, ice was 22.6 centimeters (8.9 inches) thick; it was as much as twice that thickness in some locations.
Researcher George Leshkevich said that ice cover this spring is significantly above normal.
For comparison, Lake Superior had 3.6 percent ice cover on April 20, 2013; in 2012, ice was completely gone by April 12. In the last winter that ice cover grew so thick on Lake Superior (2009), it reached 93.7 percent on March 2 but was down to 6.7 percent by April 21.
Average water temperatures on all of the Great Lakes have been rising over the past 30 to 40 years and ice cover has generally been shrinking. (Lake Superior ice was down about 79 percent since the 1970s.)
But chilled by persistent polar air masses throughout the 2013-14 winter, ice cover reached 88.4 percent on February 13 and 92.2 percent on March 6, 2014, the second highest level in four decades of record-keeping.
Air temperatures in the Great Lakes region were well below normal for March, and the cool pattern is being reinforced along the coasts because the water is absorbing less sunlight and warming less than in typical spring conditions.
Lake Superior ice cover got as high as 95.3 percent on March 19. By April 22, it was reported at 59.9 percent; Lake Huron was nearly 30.4 percent. News outlets noted that as many as 70 ships have been backed up in Lakes Michigan, Huron, and Erie, waiting for passage into ports on Lake Superior.
The U.S. Coast Guard has been grouping ships together into small convoys after they pass through locks at Sault Ste. Marie, in order to maximize ice-breaking efficiency and to protect ships from damage.
Superior is the world’s largest freshwater lake by area (82,100 square kilometers or 31,700 square miles) and the third largest by volume.
The waters average 147 meters (483 feet) in depth, and the basin is believed to hold about 10 percent of the world’s liquid fresh water.
Posted by John J. Ray (M.A.; Ph.D.).