1994 North American cold wave

500 mb height contours at 7 AM EST on January 18, 1994, showing an upper-level trough.

Cold air outbreaks are characterized by strong upper-level troughs in the atmosphere, with ridges usually located up and downstream.[3] On January 17, the 500 millibar (mb) height contours showed the low-pressure center was situated near the border of Ontario and Manitoba, just north of Minnesota, with the trough axis stretching down into the Upper Midwest. The 500 mb height contours on January 18, 1994, showed the strong trough over the Great Lakes region extending southward that brought cold air down from the North Pole. MERRA-2 reanalysis detailed the cold air funneling into the Upper Midwest from Canada on January 18, with strong winds out of the northwest. The surface analysis map on January 18 showed a low-level ridge over the Upper Midwest and surface winds blowing out of the northwest. The surface anticyclones on January 18 and 21 both exceeded 1040 mb and moved to the southeast, bringing cold air to much of the eastern half of the United States. By January 19, the upper levels showed a retreat of the low-pressure center, however, shortwave troughs were still located near the United States, and surface temperature effects with the strong anticyclone were felt for days to come.[4]

Snow was associated with this cold weather in many regions. From January 17–18, a snowstorm affected areas from the Ozarks to New England. Ice affected most of the Mid-Atlantic region. A new single-storm record was broken in Louisville, Kentucky, with 16 inches of snowfall recorded, while accumulations of sleet and freezing rain in New York City were in excess of an inch.[1]

Surface analysis map at 7 AM EST on January 18, 1994.

Maximum temperatures from 7 AM to 7 PM EST on January 18, 1994, with minimum temperatures from 7 PM to 7 AM EST on January 19, 1994. (°F)

On January 16, the Watertown, New York International Airport set an all-time record low of −43 °F (−42 °C).[5]

Indiana and Kentucky both set state records on January 19.[6]

The city of Watertown, New York, observed its coldest January on record (since 1893), with a mean temperature of 5.39 °F (−14.78 °C).[7]

Syracuse, New York's Hancock International Airport recorded a monthly mean temperature of 12.6 °F (−10.8 °C), a record low for January.[8]

Washington National Airport (later renamed Ronald Reagan Washington National Airport) had a new record-low maximum temperature for the 20th century of 8 °F (−13.3 °C).[9][10]

Cincinnati, Ohio, reached a temperature of −24 °F (−31.1 °C), just one degree short of the record. Columbus, Ohio, saw a record −22 °F (−30.0 °C),[11] and Cleveland, Ohio, reached a record of −20 °F (−28.9 °C). Erie, Pennsylvania, hit −18 °F (−27.8 °C), which at the time was a record.

On January 19, the temperature in New Whiteland, Indiana, dropped to −36 °F (−37.8 °C), the record-lowest temperature in Indiana.[12] The minimum record temperature in Kentucky was −37 °F (−38.3 °C) in Shelbyville on January 19, 1994.[13]

The lowest temperature seen in Sussex County, New Jersey, was −26 °F (−32.2 °C) on January 21, 1994.[14]^: p.3

Pittsburgh, Pennsylvania, saw its record-low temperature of −22 °F (−30 °C) on January 19, 1994.[15] Columbus, Ohio, set an all-time record-low temperature of −22 °F (−30 °C) on January 19 as well. However, the arctic blast lasted for three days from January 18 to 20.[16]

Akron, Ohio, set a record-low temperature at −25 °F (−32 °C).[1]

On January 6–7, 1994, Lake County, Minnesota, set records for the largest snow in one day as well as the most snow in one storm.[17]

Maine had its coldest month since February 1934[18] and its coldest January since 1920,[19] while Vermont had its coldest winter since 1958–1959[20] and the adjacent states of New Hampshire and Maine their coldest since 1976–1977 and 1970–1971, respectively.

Maximum and Minimum Daily Temperatures at Minneapolis-St. Paul International Airport during the cold wave.

Minneapolis–Saint Paul was one of the areas that felt major impacts from the cold wave. From 3 PM CST on January 13 to 1 PM CST on January 19, the temperature recorded at Minneapolis–Saint Paul International Airport stayed at or below zero, marking 142 continuous hours. This was the sixth-longest stretch on record from 1873 to 2014.[21] Governor Arne Carlson closed all public schools in Minnesota on January 18, with wind chills of −48 °F (−44 °C) and morning air temperatures of −26 °F (−32 °C).[22]

Chicago, Illinois, reached −21 °F (−29.4 °C)[2] with wind chills of around −70 °F (−56.7 °C),[23] the coldest day of the 1990s in Chicago by far.[24] Almost all primary and secondary schools in Chicago were closed that day. Richard Daley, then mayor of Chicago advised residents not to go outside if they don't have to. Nearly all schools in the area were closed and four people in Cook County, Illinois, died from hypothermia. Hundreds of drivers per hour complained to the AAA-Chicago Motor Club about dead automobile batteries, fuel injectors being too cold and other vehicle issues and United Airlines canceled almost half of its flights. Multiple complaints were raised about lack of power due to severed electricity lines and water companies stopped water supply to homes due to pipe explosions.[23] Many apartment renters complained to Cook County about insufficient heat.

January was also a month of extremes in Canada. Temperatures in the Yukon almost reached −50 °C (−58 °F). In Yellowknife, the temperature did not go higher than −40 °C (−40 °F) for many days. In Windsor, Ontario, the coldest temperature since 1885 was recorded on January 19 at −29 °C (−20 °F). On January 16, Scarborough, Ontario, recorded an all-time record low temperature of −35.2 °C (−31.4 °F),[25] several degrees colder than the official coldest record for Toronto,[26] which Scarborough is now a part of. The city of Toronto itself dropped to −31 °C (−24 °F), but recorded its coldest January on record with −12.4 °C (9.7 °F) at the airport.

The cold air was also accompanied by large snowfalls. The western side of Lake Ontario saw 50 centimeters (20 inches). Rapid melting and freezing near the end of January closed Toronto Pearson International Airport on January 30 for the first time in 60 years. Water shortages were also common in Goose Bay due to extreme temperatures.[1]