The early 2014 North American cold wave was an extreme weather event that extended through the late winter months of the 2013–2014 winter season, and was also part of an unusually cold winter affecting parts of Canada and parts of the north-central and northeastern United States. The event occurred in early 2014 and was caused by a southward shift of the North Polar Vortex. Record-low temperatures also extended well into March.
On January 2, an Arctic cold front initially associated with a nor'easter tracked across Canada and the United States, resulting in heavy snowfall in some areas. Temperatures fell to unprecedented levels, and low temperature records were broken across the some areas of the United States. Business, school, and road closures were common, as well as mass flight cancellations across some airports in the Midwest. Altogether, more than 200 million people were affected, in an area ranging from the Rocky Mountains to the Atlantic Ocean and extending south to include roughly 187 million residents of the Continental United States.
Origins
Beginning on January 2, 2014, sudden stratospheric warming (SSW) led to the breakdown of the semi-permanent feature across the Arctic known as the polar vortex. Without an active upper-level vortex to keep frigid air bottled up across the Arctic, the cold air mass was forced southward as upper-level warming displaced the jet stream. With extensive snow-cover across Canada and Siberia, Arctic air had no trouble remaining extremely cold as it was forced southward into the United States.
According to the UK Met Office, the jet stream dove southward (bringing cold air with it) as a result of unusual contrast between cold air in Canada and mild winter temperatures in the United States. This produced significant wind where the air masses met, leading to bitter wind chills and worsening the impacts of the record cold temperatures.
Record temperatures
United States
On January 5, 2014, Green Bay, Wisconsin was . The previous record low for this day was set in 1979.
On January 6, 2014, Babbitt, Minnesota was the coldest place in the country at .
The low temperature at O'Hare International Airport in Chicago was on January 6. The previous record low for this day was , set in 1884 and tied in 1988. The National Weather Service adopted the Twitter hashtag #Chiberia (a portmanteau of Chicago and Siberia) for the cold wave coverage in Chicago and local media adopted the term as well. In spite of cold temperatures and stiff winds which exceeded the and air temperature when Chicago set its all-time wind chill record of in 1983, Chicago did not break the record because the NWS had adopted a new wind chill formula in 2001.
The average daily temperature for the United States on January 6 was calculated to be . The last time the average for the country was below was January 13, 1997; the 17-year gap was the longest on record.
On January 7, at least 49 record lows for the day were set across the country. On the night of January 6–7, Detroit hit a low temperature of breaking the records for both dates. The high temperature of on January 7 was only the sixth day in 140 years of records to have a subzero high. On January 7, 2014, the temperature in Central Park in New York City was . The previous record low for the day was set in 1896, twenty-five years after records began to be collected by the government. Marstons Mills, Massachusetts bottomed out at on the morning of January 8, just one degree above their record low, as did Pittsburgh, which also bottomed out at , setting a new record low on January 6–7. Cleveland also set a record low on those dates at . Temperatures in Atlanta fell to , breaking the old record for January 7 of which was set in 1970. Temperatures fell to at Brasstown Bald, Georgia. Although the cold air moderated, cold temperatures even reached Florida as far south as Tampa which had a low of on January 7, 2014, 18 F below normal.
The period of December 2013–March 2014 around Illinois was the coldest four-month period on record, with average temperatures in Chicago and Rockford, Illinois around the lower 20s to the upper teens.
Canada
The coldest parts of Canada were the eastern prairie provinces, Ontario, Quebec, and the Northwest Territories. However, only southern Ontario set temperature records.
During most of the early cold wave, Winnipeg was the coldest major city in Canada. On January 6, it reached a low of , while on January 7, the low was . On both days, the temperature did not go above . Other parts of southern Manitoba recorded lows of below . On January 5, the daily high in Saskatoon was with a wind chill of −46.