November 2018’s North America snow cover set a record for any autumn month in the satellite era.
Last November’s average snow cover across North America was an estimated 5.24 million square miles, topping the previous November record of 5.11 million square miles in 2014, according to data from the Rutgers University Global Snow Lab (GSL) dating to 1966.
This extent of snow cover was about 861,000 square miles larger than average, over three times the size of Texas.
This was largely due to the anomalous snow cover over northern and parts of the central U.S., as well as southern Canada.
Persistent cold from the Northeast to the Plains to the northern and western Gulf Coast and a number of expansive winter storms gave this winter weather season a fast start, driven by a persistent southward nosedive of the jet stream.
“This permitted arctic air to plunge into a good portion of Canada, and subsequently the U.S., leading to early-season snowfall and also remaining cold enough for the snow cover to become established for the season in northerly locales,” said Rutgers University professor and New Jersey state climatologist David Robinson.
“This early cover, in turn, helped to refrigerate air masses moving across the snow-covered ground, further enhancing the cold.“
By the end of the month, every U.S. state except Florida had picked up at least a trace of snow in autumn.
In mid-November, Winter Storm Avery squeezed out the earliest-in-season flakes of snow on record at Houston’s Bush Intercontinental Airport, then proceeded to smash the earliest measurable snowfall on record in Monroe, Louisiana, Nov. 14 before dumping the second-heaviest November calendar-day snowfall on New York City.
That was followed by Winter Storm Bruce at the end of the Thanksgiving holiday weekend, a rare November blizzard in parts of the Plains and Midwest.
Dozens of cities from Maine to Kansas to Texas and the Deep South had one of the 10 coldest Novembers on record, according to the Southeast Regional Climate Center. It was the coldest November dating to 1888 in Kansas City.
Five states – Arkansas, Illinois, Mississippi, Missouri and Oklahoma – had one of their top 10 coldest Novembers dating to 1895, NOAA reported.
For the entire northern hemisphere, the GSL found it was the third-most-expansive November snow cover in their 53-year database, topped only in 1993 and 1985.
North America also had its second-most-expansive October snow cover in 2018 – topped only in 2002 – and a record September snow cover extent.
“While snow was late to arrive in Alaska, it came on early across a good portion of Canada beginning in September and moving through October,” said Robinson, adding that Canada set snow cover records in September, October and November.
We are right in the little Ice Age!