Extreme cold warning

Last updated

An extreme cold warning is a weather warning issued by Environment and Climate Change Canada (ECCC) and by the United States' National Weather Service (NWS) to inform the public about active or imminent severe cold temperatures in their local region.

Contents

In April 2014, ECCC replaced the "wind chill warning" with an "extreme cold warning." In the older system a wind chill warning for Southern Ontario and Atlantic Canada was issued when the wind chill dropped to -35. Thus a temperature of −37 °C (−35 °F) with no winds would not require a warning be issued. Under the new system the extreme cold warning is issued based on either the temperature or the wind chill being a certain value for at least two hours. The values range from −30 °C (−22 °F) in the warm temperates to −55 °C (−67 °F) in parts of the Arctic. [1] [2]

On October 1, 2024, the NWS replaced the "wind chill warning" with the "extreme cold warning." The standards governing issuance are set by local NWS offices. The 'step' below an extreme cold warning is an "extreme cold watch," which itself replaced the "wind chill watch" in October 2024. [3] [4]

Canada

An extreme cold warning is issued when the following temperatures are expected to last for at least two hours, which different regions have different criteria for: [2]

United States

In the United States an extreme cold warning was an experimental weather warning issued by the National Weather Service in North Dakota, South Dakota, and Minnesota. [5] The warning was issued if the temperature fell to −35 °F (−37 °C) or colder with a wind of less than 5 mph (8 km/h; 2 m/s). [6] It was an experimental advisory for when the air temperature was dangerously cold, but the wind was too little to warrant a Wind Chill Watch or Warning. [7]

The Extreme Cold Warning was used from January 10, 2011 to April 15, 2011. [8] It was discontinued beginning with the 2011-12 winter storm season. Only five Extreme Cold Warnings were issued in that period: one for Burleigh County, three for areas outside of the Bismarck–Mandan metropolitan area, and one for West Glacier, Montana [9]

In a partner webinar on October 30, 2018, the National Weather Service announced that based on survey feedback, the Extreme Cold Warning and the Wind Chill Warning will be consolidated into the Extreme Cold Warning, meaning that this product would once again be issued on a regular basis. This change was hinted to take effect sometime in 2021, accounting for NWS software upgrades. [10] [11] This was confirmed at the AMS 2024 meeting in January 2024.

In October 2024, the NWS officially implemented these changes to its wind chill and hard freeze warnings, watches, and advisories (WWAs) as part of its "Hazard Simplification initiative." The goal of these WWA name changes, per the NWS, is "simplifying a suite of cold weather forecast products to improve messaging of winter hazards and provide better decision support." The changes include: [12] [13]

Extreme Cold Consolidation and Renaming

Freeze Consolidation


Local NWS offices will still determine the standards governing the issuance of such WWAs.

Example

URGENT - WEATHER MESSAGE National Weather Service Fairbanks AK 332 AM AKST Fri Dec 13 2024  AKZ834-835-140100- /O.CON.PAFG.EC.W.0001.241215T0000Z-241215T1800Z/ White Mountains and High Terrain South of the Yukon River- Fortymile Country- Including the cities of The Taylor Highway north of MP 9, The Dalton Highway from MP 0 to MP 38, Livengood, Chicken, Circle Hot Springs, Twelvemile Summit, The Steese Highway from MP 85 to MP 124, Eagle Summit, Eagle, and The Elliott Highway from MP 32 to MP 134 332 AM AKST Fri Dec 13 2024  ...EXTREME COLD WARNING REMAINS IN EFFECT FROM 3 PM SATURDAY TO 9 AM AKST SUNDAY...  * WHAT...Dangerously cold with wind chill as low as 60 below   expected.  * WHERE...Fortymile Country and White Mountains including Eagle   Summit, Chicken, and Eagle.  * WHEN...From 3 PM Saturday to 9 AM AKST Sunday.  * IMPACTS...The dangerously cold wind chills as low as 60 below zero   could cause frostbite on exposed skin in as little as 5 minutes.  PRECAUTIONARY/PREPAREDNESS ACTIONS...  Dress in layers including a hat, face mask, and gloves if you must go outside. If traveling, be prepared with extra gear to remain warm and hydrated.  &&  $$

See also

Related Research Articles

<span class="mw-page-title-main">Wind chill</span> Lowering of body temperature due to the passing flow of lower-temperature air

Wind chill is the sensation of cold produced by the wind for a given ambient air temperature on exposed skin as the air motion accelerates the rate of heat transfer from the body to the surrounding atmosphere. Its values are always lower than the air temperature in the range where the formula is valid. When the apparent temperature is higher than the air temperature, the heat index is used instead.

<span class="mw-page-title-main">National Weather Service</span> U.S. forecasting agency of the National Oceanic and Atmospheric Administration

The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the Department of Commerce, and is headquartered in Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1891 until it adopted its current name in 1970.

This article describes severe weather terminology used by the National Weather Service (NWS) in the United States, a government agency operating within the Department of Commerce as an arm of the National Oceanic and Atmospheric Administration (NOAA).

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 criteria for a cold wave are 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.

This article describes severe weather terminology used by the Meteorological Service of Canada, a branch within Environment and Climate Change Canada. The article primarily describes various weather warnings, and their criteria. Related weather scales and general weather terms are also addressed in this article. Some terms are specific to certain regions.

In weather forecasting in the United States, "particularly dangerous situation" (PDS) is enhanced wording used by the National Weather Service to convey special urgency in some watch or warning messages for unusually extreme and life-threatening severe weather events, above and beyond the average severity for the type of event. It is used in the format "This is a particularly dangerous situation..." at the discretion of the issuing forecaster. A watch or warning bearing the phrase is referred to as a PDS watch or PDS warning as shorthand jargon.

A weather warning generally refers to an alert issued by a meteorological agency to warn citizens of approaching dangerous weather. A weather watch, on the other hand, typically refers to an alert issued to indicate that conditions are favorable for the development of dangerous weather patterns, although the dangerous weather conditions themselves are not currently present.

A cold weather advisory is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public that temperatures or wind chills are forecast to reach values low enough that it poses a threat to human health and life if adequate protection is not taken against hypothermia and frostbite. The exact criteria meriting the issuance of an advisory varies from state to state, and areas prone to colder temperatures will often require colder temperatures/wind chills before issuing an advisory.

A wind chill watch is a weather watch formerly issued by the National Weather Service of the United States when the wind chill could reach dangerous levels within the next 12 to 48 hours; as of October 2024 it has been re-named "extreme cold watch." The exact definition required to issue a watch varies from state to state or from National Weather Service county warning areas to another, but if forecasters believe conditions are favorable for life-threatening wind chills meeting local criteria, a watch will be issued. People going outside should plan to protect themselves against hypothermia and frostbite. In October 2024, the "wind chill watch" and "wind chill warning" were, among other changes, re-named in-favor of a "simplified" naming scheme.

A wind chill warning was a hazardous weather statement previously issued by both local forecast offices of the National Weather Service (NWS) in the United States and by the Meteorological Service of Environment and Climate Change Canada (ECCC) when wind chills were forecast to reach values low enough for residents and travelers to be susceptible to life-threatening medical conditions or death associated with accelerated body heat loss. In both Canada and the United States, the "wind chill warning" has been replaced with the "extreme cold warning."

<span class="mw-page-title-main">1994 North American cold wave</span> Weather event

The 1994 North American cold wave occurred over the midwestern and eastern regions of the United States and southern Canada in January 1994. The cold wave caused over 100 deaths in the United States. Two notable cold air events took place from January 18–19 and January 21–22. There were 67 minimum temperature records set on January 19. During this time, much of the United States experienced its coldest temperatures since a major storm on February 20, 1934.

<span class="mw-page-title-main">January–March 2014 North American cold wave</span> Extreme weather event affecting parts of Canada and the United States

The January–March 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.

<span class="mw-page-title-main">2018–19 North American winter</span> North American winter of 2018–19

The 2018–19 North American winter was unusually cold within the Northern United States, with frigid temperatures being recorded within the middle of the season. Several notable events occurred, such as a rare snow in the Southeast in December, a strong cold wave and several major winter storms in the Midwest, and upper Northeast and much of Canada in late January and early February, record snowstorms in the Southwest in late February, deadly tornado outbreaks in the Southeast and a historic mid-April blizzard in the Midwest, but the most notable event of the winter was a record-breaking bomb cyclone that affected much of the Central United States and Canada in mid-March. Unlike previous winters, a developing weak El Niño was expected to influence weather patterns across North America. Overall, however, winter of 2018–19 had many La Niña like conditions, being mild along the mid- and lower parts of the East Coast, the West Coast, and most of the southern Plains. Overall, the meteorological winter of 2018-19 became the wettest on record for the United States.

<span class="mw-page-title-main">January–February 2019 North American cold wave</span> Fatal cold wave in the US and Canada

In late January 2019, a severe cold wave caused by a weakened jet stream around the Arctic polar vortex hit the Midwestern United States and Eastern Canada, killing at least 22 people. It came after a winter storm brought up to 13 inches (33 cm) of snow in some regions from January 27–29, and brought the coldest temperatures in over 20 years to most locations in the affected region, including some all-time record lows. In early February, a concentration of Arctic air colloquially referred to as the "polar vortex" moved west, and became locked over Western Canada and the Western United States. As a result, February 2019 was among the coldest and snowiest on record in these regions. In early March, the cold once again shifted east, breaking records in many areas. In mid-March, the cold wave finally retreated, but combined with above-average temperatures, precipitation, and a deep snowpack, widespread flooding ensued in the Central US.

<span class="mw-page-title-main">2019–20 North American winter</span> Winter season in North America

The 2019–20 North American winter was unusually warm for many parts of the United States; in many areas, neutral ENSO conditions controlled the weather patterns, resulting in strong El Niño like conditions and the sixth-warmest winter on record, and many areas in the Northeastern United States saw one of the least snowy winters in years. In fact, Baltimore and Islip saw no snow in February for the first time. Some notable events still occurred, such as a powerful blizzard that impacted the Western United States in late November, a series of cold shots in January and February, a snowstorm within the Texas Panhandle and a late-season blizzard in the High Plains.

<span class="mw-page-title-main">2020–21 North American winter</span> Winter season in North America

The 2020–21 North American winter was the most significant winter season to affect North America in several years, and the costliest on record, with a damage total of at least $33.35 billion. The season featured six storms ranking on the Regional Snowfall Index scale (RSI), with four storms ranking as at least a Category 3. Most of the winter's damage and fatalities occurred due to a historic and major cold wave in mid-February. Several other significant events occurred, including a crippling early-season ice storm in the Southern Plains, a powerful nor'easter in mid-December, another major nor'easter in early February, two major and widespread winter storms in mid-February, and a major blizzard in the Rocky Mountains in mid-March. The winter-related events were responsible for at least 358 fatalities, making it the deadliest season since 1992–93. A La Niña pattern influenced much of the winter in North America.

<span class="mw-page-title-main">February 13–17, 2021 North American winter storm</span> Category 3 winter storm and ice storm in the United States

The February 13–17, 2021 North American winter storm was a crippling, large and major winter and ice storm that had widespread impacts across the United States, Northern Mexico, and parts of Canada from February 13 to 17, 2021. The storm, unofficially referred to as Winter Storm Uri by the Weather Channel, started out in the Pacific Northwest and quickly moved into the Southern United States, before moving on to the Midwestern and Northeastern United States a couple of days later.

<span class="mw-page-title-main">2022–23 North American winter</span> Winter season in North America

The 2022–23 North American winter was an unusually warm winter for the east and an unusually cold winter for the west in North America, as it occurred across the continent from late 2022 to early 2023. The winter season in North America began at the winter solstice, which occurred on December 21, 2022, and it ended at the March equinox, which occurred on March 20, 2023. The first day of meteorological winter began on December 1 and unofficially ended on February 28; winter storms may still occur outside of these limits.

<span class="mw-page-title-main">December 2022 North American winter storm</span> North American winter storm in 2022

From December 21 to 26, 2022, an extratropical cyclone created crippling winter storm conditions, including blizzards, high winds, snowfall, and record cold temperatures across the majority of the United States and parts of Canada. Impacted areas include parts of Minnesota, Iowa, Wisconsin, Michigan, Ohio, Pennsylvania, New York, and Ontario, with Buffalo, New York and the Fort Erie and Kingston areas of Ontario experiencing two full days of hazardous conditions and zero-visibility. The cold wave affected all U.S. states from Colorado to the Eastern Seaboard, with effects felt as far south as Miami, Florida. On December 24, 110 million people across 36 states were subject to wind chill alerts.

An extreme cold watch is a weather watch issued by the United States' National Weather Service (NWS) to inform the public that "dangerously cold air, with or without wind, is possible." The extreme cold watch is a 'step' below the "extreme cold warning."

References

  1. ↑ Environment Canada. "Wind Chill Hazzards". Archived from the original on December 17, 2005.
  2. 1 2 Extreme Cold Warning
  3. ↑ Michael Musher, National Weather Service Public Affairs. "National Weather Service Revises Watch, Warning and Advisory Products". News Around NOAA. Archived from the original on 2024-10-07. Retrieved 2024-10-10.
  4. ↑ Blaise Keller. "Beyond the Barometer: Changes coming to wind chill alerts". Wisconsin State Journal. Archived from the original on 2024-10-08. Retrieved 2024-10-10.
  5. ↑ "National Weather Service Plans to Issue 'Extreme Cold Warnings'". Archived from the original on 2013-06-16.
  6. ↑ "NWS To Experiment With 'Extreme Cold' Warnings". 10 January 2011.
  7. ↑ "Experimental Cold Warning Feedback Needed".
  8. ↑ "NWS Tests Extreme Cold Warning". Archived from the original on 2013-06-09.
  9. ↑ "National Weather Service ditching 'extreme cold' warnings".
  10. ↑ "National Weather Service Public Information Statement PNS18-11" (PDF). Retrieved February 1, 2019.
  11. ↑ "Update on Winter Weather Initiatives Partner Webinar" (PDF). Retrieved February 1, 2019.
  12. ↑ Michael Musher, National Weather Service Public Affairs. "National Weather Service Revises Watch, Warning and Advisory Products". News Around NOAA. Archived from the original on 2024-10-07. Retrieved 2024-10-10.
  13. ↑ Blaise Keller. "Beyond the Barometer: Changes coming to wind chill alerts". Wisconsin State Journal. Archived from the original on 2024-10-08. Retrieved 2024-10-10.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.