Cold wave


A cold wave is a weather phenomenon that is distinguished by a cooling of the air. Specifically, as used by the U.S. National Weather Service, a cold wave is a rapid fall in temperature within a 24-hour period requiring substantially increased protection to agriculture, industry, commerce, and social activities. The precise criterion for a cold wave is determined by the rate at which the temperature falls, and the minimum to which it falls. This minimum temperature is dependent on the geographical region and time of year.
In the United States, a cold spell is defined as the national average high temperature dropping below. A cold wave of sufficient magnitude and duration may be classified as a cold air outbreak.

Effects

A cold wave can cause death and injury to livestock and wildlife. Exposure to cold mandates greater caloric intake for all animals, including humans, and if a cold wave is accompanied by heavy and persistent snow, grazing animals may be unable to reach needed food and die of hypothermia or starvation. They often necessitate the purchase of foodstuffs to feed livestock at considerable cost to farmers.
Cold spells are associated with increased mortality rates in populations around the world. Both cold waves and heat waves cause deaths, though different groups of people may be susceptible to different weather events. In developed countries, more deaths occur during a heat wave than in a cold snap, though the mortality rate is higher in undeveloped regions of the world. Globally, more people die during hot weather than cold weather. Extreme winter cold often causes poorly insulated water pipelines and mains to freeze. Even some poorly protected indoor plumbing ruptures as water expands within them, causing much damage to property and costly insurance claims. Demand for electrical power and fuels rises dramatically during such times, even though the generation of electrical power may fail due to the freezing of water necessary for the generation of hydroelectricity. Some metals may become brittle at low temperatures. Motor vehicles may fail when antifreeze fails or motor oil gels, producing a failure of the transportation system. To be sure, such is more likely in places like Siberia and much of Canada that customarily get very cold weather.
Fires become even more of a hazard during extreme cold. Water mains may break and water supplies may become unreliable, making firefighting more difficult. The air during a cold wave is typically denser and thus contains more oxygen, so when air that a fire draws in becomes unusually cold it is likely to cause a more intense fire. However, snow may stop spreading of fires, especially wildfires.
Winter cold waves that are not considered cold in some areas, but cause temperatures significantly below average for an area, are also destructive. Areas with subtropical climates may recognize unusual cold, perhaps barely freezing, temperatures, as a cold wave. In such places, plant and animal life is less tolerant of such cold as may appear rarely. The same winter temperatures that one associates with the norm for Colorado, Ohio, or Bavaria are catastrophic to winter crops in places like
Florida, California, or parts of South America that grow fruit and vegetables in winter.
Cold waves that bring unexpected freezes and frosts during the growing season in mid-latitude zones can kill plants during the early and most vulnerable stages of growth, resulting in crop failure as plants are killed before they can be harvested economically. Such cold waves have caused famines. At times as deadly to plants as drought, cold waves can leave a land in danger of later brush and forest fires that consume dead biomass. One extreme was the so-called Year Without a Summer of 1816, one of several years during the 1810s in which numerous crops failed during freakish summer cold snaps after volcanic eruptions that reduced incoming sunlight.

Countermeasures

In some places, such as Siberia, extreme cold requires that fuel-powered machinery to be used even part-time must be run continuously. Internal plumbing can be wrapped, and persons can often run water continuously through pipes. Energy conservation, difficult as it is in a cold wave, may require such measures as collecting people in communal shelters. Even the homeless may be arrested and taken to shelters, only to be released when the hazard abates. Hospitals can prepare for the admission of victims of frostbite and hypothermia; schools and other public buildings can be converted into shelters.
People can stock up on food, water, and other necessities before a cold wave. Some may even choose to migrate to places of milder climates, at least during the winter. Suitable stocks of forage can be secured before cold waves for livestock, and livestock in vulnerable areas might be shipped from affected areas or even slaughtered. Smudge pots can bring smoke that prevents hard freezes on a farm or grove. Vulnerable crops may be sprayed with water that will paradoxically protect the plants by freezing and absorbing the cold from surrounding air.
Most people can dress appropriately and can even layer their clothing should they need to go outside or should their heating fail. They can also stock candles, matches, flashlights, and portable fuel for cooking and wood for fireplaces or wood stoves, as necessary. However caution should be taken as the use of charcoal fires for cooking or heating within an enclosed dwelling is extremely dangerous due to carbon monoxide poisoning. Adults must remain aware of the exposure that children and the elderly have to cold.

Historical cold waves

21st-century cold waves (2001–present)

2020
2019
2018
2017–2018
2017
2016
2014–2015
2013–2014
2013
2012
2010–2011
2009–2010
The first snowfall began on 17 December 2009, before a respite over the Christmas period. The most severe snowy weather began on 5 January in North West England and west Scotland with temperatures hitting a low of in Greater Manchester, England. The snow spread to Southern England on 6 January and by 7 January the United Kingdom was blanketed in snow, which was captured by NASA's Terra satellite. The thaw came a week later, as temperatures started to increase. The winter weather brought widespread transport disruption, school closures, power failures, the postponement of sporting events and 25 deaths. A low of was recorded in Altnaharra, Scotland on 8 January 2010. Overall it was the coldest winter since 1978–79, with a mean temperature of.
2008
2007
2005–2006
2004–2005
1997
1996
1995
1994
1990–1991
1989
1987
1985–1986
1985
1983
1981–1982
1979
1978
1977
1977–1979 winters
1968–1969
1966
  • 1966 Western Canadian cold wave – January 1966 was the coldest January on record in the Yukon and the coldest since 1950 or 1936 in the Prairie Provinces, and the severe cold continued into March, when Winnipeg recorded its most severe winter snowstorm on record.
1962–1963
  • January 1963 cold wave in Mid-Western United States, as well as a brief-but-severe cold spell in the western United States.
  • Winter of 1962–63 in the United Kingdom – The winter of 1962–63 was the coldest for 223 years in England, and the freeze was accompanied by strong easterly winds and the freezing of rivers and streams.
1956
  • 1956 European cold wave – February 1956 was the coldest month of the twentieth century over large areas of Western Europe, with mean temperatures below as far south as Marseilles being utterly unprecedented in records dating back into the eighteenth century.
1954-1955
  • Winter of 1954–1955 in East Asia – One of the coldest winters on record across China. Numerous major rivers and lakes froze over, including the Huai River, Han River, and Dongting Lake.
1950
  • 1950 Northwest North American cold wave – January 1950 saw unprecedented cold and snowfall in the Pacific Northwest, with normally mild Seattle and Portland, Oregon both falling below and receiving extremely heavy snow that disrupted transport and schooling as it could not be removed easily. Western Canada saw by far its coldest month on record, leading to severe damage to fruit crops in the Okanagan Valley, the freezing of Okanagan Lake for the only time since 1862, and Calgary's only month where temperatures remained below throughout. Vancouver, British Columbia had an average temperature of, compared to the average.
1949
  • January 1949 Western United States cold wave – The winter of 1948–49 was the coldest since 1891 over the Western United States and saw record snowfall, ice storms as far south as Texas, and constant disruptions to surface transport, along with large losses in livestock and crops. Coldest winter was recorded in many places in California, Nevada, Idaho and Washington state. The cold was also accompanied by severe blizzards which isolated Wyoming ranches and paralyzed the Great Basin region. The U.S. Army ran "Operation Hay Lift" in the region to bring food and hay by plane to isolated ranches in the region. Las Vegas Nevada got a record of snowfall during the month of January. Snow fell in both San Diego and Los Angeles on three days in January 1949. All-time record low of 0F in San Antonio, Texas.
1941–1942
1940
  • January 1940 Southern United States cold wave – Late January saw record-breaking cold and snow across the Southern United States. It was the coldest month there since February 1899.
1937
  • 1937 Western United States cold wave – January 1937 was the coldest month on record in the West and saw snowfall as far south as the hot desert city of Yuma, Arizona for one of only two occasions on record. California and Nevada saw their lowest temperatures on record: at Boca on January 20 and at San Jacinto on January 8.
1936
  • 1936 North American cold wave – The cold wave of 1936 was the only cold wave of the 1930s to severely impact the United States east of the hundredth meridian. One of the coldest winters in the Great Plains on record. Low temperatures dropped below in Malta, Montana on four separate days and most of Montana averaged 20 degrees below normal for the entire month of February Parshall, North Dakota hit on February 15, still a record. Langdon, North Dakota remained below for 41 straight days from January 11 to February 20, the longest stretch in recorded history for the U.S. outside of Alaska. The cold wave was followed by one of the hottest summers on record, the 1936 North American heat wave.
1934
  • February 1934 Cold Wave in New England and Eastern Canada – Longest period of cold weather ever experienced to this point. Average temperatures in upper New England were around zero degrees Fahrenheit for most of the month. Temperatures reached above freezing only on one day in Burlington, VT in February.
1933
  • 1933 Western United States cold wave – The winter of 1932–33 was the second- or third-coldest on record in most of the West and saw record cold temperatures in Oregon, Wyoming and Texas between February 7 and 10, when sixty deaths were blamed on extreme cold and ice storms.
1932
  • Major cold outbreaks affected California in January, February and December. Up to two inches of snow fell across the Los Angeles Basin on January 15, and two inches of snow was officially recorded at the Downtown Los Angeles Weather Bureau Office. Snow also fell in San Francisco on three days in December 1932.
1930
  • A cold wave gripped the western United States in January 1930. Two inches of snow fell in Palm Springs, CA on January 11, one of only two times in the city's history that snow was ever observed.
1917-1918
  • Winter of 1917–1918 – The winter was very frigid across the East and created a heating fuel crisis equaled only in January 1977. Severe cold wave in December 1917 and January 1918 in northeast. December 30 set a number of record lows at the time in New York City and Boston. Under ideal conditions for radiational cooling, including fresh snow cover and mostly clear skies, the morning of December 30, 1917 was exceptionally cold also in parts of Virginia and West Virginia, with all-time record cold temperatures recorded in many cities, including at Lewisburg, at White Sulphur Springs, West Virginia, at Bluefield, West Virginia, and at Blacksburg and Burkes Garden, Virginia. January 1918 also brought persistent well below average temperatures for many parts of the East and Midwest, with another shot of very cold air in early February. The Ohio River froze solidly along its entire length.
1916-1917
  • Winter of 1916–1917 – the "extended winter" of 1916–17 was the coldest on record in the West and Midwest.
1912
1904''' was the coolest year on record.

19th century cold waves (1801–1900)

1899
1888
1886–1887
1882–1883
1874–1875
1859
1857
1835