By Frank Lombardo
I hope you were hanging on tight during the roller coaster winter of 2017-2018. The extreme swings in weather, similar to those recently seen in financial markets, brought rapid changes to much of the country. Most noteworthy were some of the worst forest fires in years to hit the Southwest, ice storms across the nation’s mid-section, a winter month of unseasonable warmth, and four late-season Nor’easters that lingered into early April.
Heading into the 2017-2018 winter season, much of North America was experiencing warmer than normal weather. Despite the above normal temperatures, the snow season got off to an early start across the United States and Canadian Rockies; and according to the National Oceanic and Atmospheric Administration, by November 8 over 25% of the area of the lower 48 had snow on the ground. This was the largest coverage of snow on that date in at least 14 years.
Winter 2017-2018 continued as a story of fire and ice. December featured forest fires in the West where the largest fire in California history forced the evacuation of 230,000 people and scorched 280,000 acres of land. Meanwhile, from December 8-10, a storm dropped snow and ice from New Mexico to Maine. The storm left parts of Alabama, Georgia and North Carolina with 12 inches of snow and a large swath of the first widespread plowable snow all the way up to Maine.
While Alaska was basking in its warmest December ever, an arctic air mass finally began a slow assault into the United States via Canada during the holiday season. The invasion of the season’s coldest air continued through early January causing many temperature records to fall. Chicago had its most frigid New Year’s Day with the temperature barely breaking above 0°F for the high. International Falls, MN, dipped to -37°F; and on Jan. 5 Toronto broke a record at -23°C (-9°F). This super-charged arctic air produced the heaviest lake effect snows ever recorded in Erie, PA. Beginning late on Christmas Eve and continuing into Dec. 27, Erie International Airport recorded more than 65 inches of snow, shattering the daily record. This is more snow than Boston, Chicago or Minneapolis typically see in an entire winter.
The “bomb” drops
In the midst of the Arctic outbreak, our industry was introduced to a new meteorological expression: Bombogenesis. This term is used to define the explosive development of a low pressure storm. As the intense cold arctic air mixed with warmer air over the Atlantic Ocean, an explosion of atmospheric energy occurred. The highly touted “bomb cyclone” on Jan. 3-5 rapidly intensified, bringing 2 feet of snow to areas along the Atlantic coast and Eastern Canada. The hurricane-like storm whipped up 70 to 90 mph winds, causing blinding whiteouts, drifting snow and flooding Boston streets with water that turned to sheets of ice. Northern Florida saw a dusting of snow for the first time since 1977 and parts of central Maine got buried under nearly 4 feet of snow.
Just as quickly as the Arctic air had arrived, it was gone. Across much of the East and South, the cold air melted away with uncharacteristic heat that spread from south to north in February. After some early bouts with cold and a few light snows, summer-like weather took over from the Gulf of Mexico to the Ohio Valley and Maine. By Feb. 20, temperatures had skyrocketed to all-time records with readings approaching or exceeding 80°F in every state on the Atlantic seaboard and in the Ohio Valley.
Meanwhile, winter weather receded back into the Rockies, Northern Plains and Upper Midwest. The Chicago metro area saw a record nine consecutive days of measurable snow at the start of the month with snowfall totals of 18.3 inches compared to no snowfall the prior year. Icy weather plagued the plains through mid-February with oscillating temperatures near freezing.
And then there was March. A series of four Nor’easters pummeled the Midwest, East Coast and eastern Canada in a 3-week span. Record snows of over 4 feet during March were common across northern New England, producing one of the snowiest months on record. In fact, some contractors along the East Coast saw more work in March and into spring than they had seen all winter.
Season of extremes
East coast deluge
Early start/late surge
: According to the National Oceanic and Atmospheric Administration, the United States experienced its largest snow coverage so early in a season in at least 14 years. By Nov. 8, 25% of the lower 48 states had snow. This included southern states such as Alabama, Georgia and North Carolina. After some lulls in February, winter roared back, particularly along the East Coast.
: Anchorage, AK, basked in its warmest December on record as an arctic air mass began to infiltrate the United States via Canada. January brought in some of the coldest arctic air with records broken in cities like Chicago, Toronto and International Falls, MN. Just as quickly as those records fell, February ushered in record heat along the Atlantic seaboard and in the Ohio Valley, with temperatures above 80°F in many areas. Those warm temperatures also resulted in February being the 5th wettest on record.
In this Jan. 3-5 blizzard, which featured the bombogenesis phenomenon (\show above), record winds, storm surges and snowfall were recorded up and down the Atlantic coast. After a mild reprieve, parts of the coast experienced four Nor’easters that resulted in some northern states experiencing record snowfalls.
Data Courtesy of NOAA/NOHRSC
2017-2018 Snowfall vs. Average
Several cities exceeded their averages in 2017-18 due to early season blasts and a series of late storms. Erie, PA, decimated its average, recording more than 186”, more than 3’ higher than its previous record of 149”. About 35% of that snowfall total fell in one December storm.
Frank Lombardo is president and an AMS Certified Consulting Meteorologist, and Ken Elliott is a Meteorologist for WeatherWorks Inc. Contact them at firstname.lastname@example.org or email@example.com.
- 413% - Baltimore, MD saw a dramatic year-over-year increase (from 3” in 2016-17 to 15.4”) but still didn’t hit its average (20.1”).
- 145% - Minneapolis, MN recorded a substantial increase in snow from 32” in 16-17 to 78.3”. The city also exceeded its average by 23.9”.
- -28% - Anchorage, AK exceeded its 74.5” average in 16-17 with 82.4” but saw a 23.4% year-over-year decrease and -28% departure from average.