From Wikipedia, the free encyclopedia
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.[1]
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 at
considerable cost to farmers to feed livestock.
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 as antifreeze fails and
motor oil gels, resulting even in the 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 any
cold air that a fire draws in is likely to cause a more intense
fire because the colder, denser air contains more oxygen.
Winter cold waves that aren't 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 Kentucky, northern Utah, or Bavaria would be catastrophic to winter crops
in southern Florida,
southern Arizona, or
southern Italy that might be
grown for wintertime consumption farther north, or to such all-year
tropical or subtropical crops as citrus fruits.
Likewise, abnormal cold waves that penetrate into tropical
countries in which people do not customarily insulate houses or
have reliable heating may cause hypothermia and even frostbite.
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 (especially the poor and elderly) in communal
shelters. Even the homeless may be arrested and taken to shelters, only to be
released when the hazard abates.[2]
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. (The freezing of water releases heat that
protects the fruit.)
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
Modern cold waves
(2001-date)
- Early 2009 European Cold Wave - Early January gave most of
Europe, especially in central and south very cold temperatures.
Some places like Germany, France, Italy, Romania and Spain had record cold temperatures well below
0°C. Most of the places were covered in snow and ice which caused
school closings and airport delays. Large cities like Paris, Madrid, Berlin and even Marseille saw very cold temperatures with
lots of snow and ice in Northern Italy, most of Germany, in
northern Portugal and even
along the coasts of the Mediterranean. In
early February another cold front brought heavy snowfall to much of
Western Europe with the heaviest snow falling in France, Northern
Italy, the Low Countries and the United Kingdom, where parts of Southern
England had seen the worst snowfall in over 18 years causing
widespread travel disruption particularly around London.
- 2008 North American Cold Wave - In December, Canada and large parts of the United States
experienced very heavy snowfall and plummeting temperatures.
Snowfall was seen in unusual areas along the Great Plains and even
in the deserts in and around Las Vegas. Also, over a foot of snow
fell in Seattle and other parts of the lowland
Pacific Northwest. Mexico experienced a number of cold waves in
October, December and January, with temperatures below 0°C.
- 2008 Alaska - In early February Alaska experienced some of the
coldest temperatures for 8 years, with Fairbanks nearing
(-50 °F (-46 °C) and Chicken, Alaska bottoming out at
-72 °F (-58 °C), a mere 8 degrees away from the record of
-80 °F (-62 °C). The first half of January also brought
unusual cold weather and heavy snow to widespread regions of China and the Middle East.
- 2007 Argentine cold wave - An interaction with an area of low
pressure systems across Argentina during the July 6, July 7 and 8 of
2007, and the entry of a massive polar cold snap resulted in severe snowfalls
and blizzards, and
recorded temperatures below -30º C. The cold snap advanced from the
south towards the central zone of the country, continuing its
displacement towards the north during Saturday, July 7. On Monday
July 9, the simultaneous presence of very cold air, gave place to
the occurrence of snowfalls. This phenomenon left at least
23 people dead.[3][4]
- 2007 Northern Hemisphere cold wave - All of Canada and most of
the United States underwent a freeze after a two-week warming that
took place in late March & early April. Crops froze, wind
picked up, and snow drizzled much of the United States. Some parts
of Europe also experienced unusual cold winter-like temperatures,
during that time.
- 2005-2006 European cold wave - Eastern Europe and Russia saw a
very cold winter. Some of them saw their coldest on record or since
the 1970s. Snow was an abundance in unusual places, such as in
southern Spain and Northern Africa. All the winter months that
season saw temperatures well below average across the
continent.
- 2004-2005 Southern Europe cold wave - All areas of Southern
Europe saw an unusually hard winter. This area saw an ice storm which have a 1 in
1000 chance of happening. This cold front caused snow in Algeria, which is extremely
unusual. The south of Spain and Morroco also recorded freezing
temperatures, and record freezing temperatures were observed on the
north of Portugal and Spain.
- 2004 January cold outbreak, Northeast United States - New
England was near a record month when frequent Arctic fronts caused
unusually cold weather. Boston
was one of their coldest in 114 years. Virginia Beach had an unusually long
period of below freezing
weather. One area of New
York saw 150 inches of snow in a month. Many parts of the
western and midwestern area of the country seen the effect as
well.
20th
century cold waves
- 1997 Northern Plains cold air Outbreak - Mid January across the
Northern U.S. was one of the windiest on record. With a low of
around -40 °F in some places, wind caused bitterly cold wind chills sometimes
nearing -80 °F. Northern parts of North Dakota saw up to 90 inches of
snow. This was one of the most severe cold air outbreaks of the
1990s.
- 1996 Great Midwest cold outbreak - Late January and early
February was Northern Minnesota's coldest short term period on
record. The record low of -60 °F was recorded in Tower,
Minnesota.
- 1994 Northern US/Southern Canada cold outbreak - January 1994
was the coldest month recorded over many parts of the northeast and
north-central United States, as well as Southern Canada, or coldest
since the late 1970s in some locations. Many overnight record lows
were set. Cold outbreaks continued into February but the severity
eased somewhat. The cold also extended further south than usual
into Texas bringing snowfall and temperatures lower than -20 °F to
parts of the state, Florida also experienced cold and snowfall,
even once flurries were reported north of Miami and damage to the
citrus crop in central Florida was extensive. Detroit, Michigan saw their coldest
temperature since 1985.
- 1989 record cold start to December - In 1989, the central and
eastern USA saw
one of the coldest Decembers on record. A white Christmas
occurred.
- 1985 Great Western cold air outbreak - February 1985 saw the
USA's third coldest temperature of -69 °F in Peter's Sink, Utah. About a month of severe cold
affect a large part of the nation. 1985 became the fourth coldest
year on record in the western USA.
- 1983 Record cold December USA - USA had its coldest ever Christmas in 1983. Severely
cold winds blew in from Canada
and about 70% of the month was colder than average. The 1980s saw
the USA's coldest Decembers on record.
- 1982 cold air outbreak - January 1982 was very cold. The 1981 AFC Championship Game, held in
Cincinnati was nicknamed the "Freezer Bowl" due to the -9 °F temperature
and -59 °F wind chill. The following week's events was also known
as Cold Sunday
- 1970s - In the late 1970s most or all places in the Lower 48
had at least one winter with a memorable cold wave, and the 1977-78 cold
wave was the coldest winter on record in the lower 48, with
every state seeing well below average temperatures.
- 1936 Cold wave - The cold wave of 1936 was the
only cold wave of the 1930s impacting North America and the Midwest
United States.
- 1910s - The severe cold outbreak of
1912 caused the longest recorded period of below zero weather.
The winter from 1916–1917 until 1917–1918 was very frigid across the USA.
See also
References
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