A winter storm is an event in which wind coincides with varieties of precipitation that only occur at freezing temperatures, such as snow, mixed snow and rain, or freezing rain. In temperate continental and subarctic climates, these storms are not necessarily restricted to the winter season, but may occur in the late autumn and early spring as well. A snowstorm with strong winds and other conditions meeting certain criteria is called a blizzard.
A winter storm warning 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 a winter storm is occurring or is about to occur in the area, usually within 36 hours of the storm's onset.
A blowing snow advisory was issued by the National Weather Service of the United States when wind driven snow reduces surface visibility and possibly hampers traveling. Blowing snow may be falling snow, or snow that has already accumulated but is picked up and blown by strong winds. This advisory was discontinued beginning with the 2008–09 winter storm season, replaced by the winter weather advisory for snow and blowing snow. However, if the storm is judged to be dangerous by local forecasters, a winter storm warning for heavy snow and blowing snow may be issued.
A winter storm watch is issued by the National Weather Service of the United States when there is a possibility of heavy snow or potential of significant ice accumulations, without meeting a specific other winter criteria. The watch is typically issued 12 to 48 hours before the storm's expected arrival in the given area. The criteria for this watch can vary from place to place, which is true with other winter weather warning and advisories.
A lake effect snow advisory was issued by the National Weather Service of the United States when lake effect snow may pose a hazard or is life-threatening. The snow must be completely caused by a convective snow development over a lake and not by a low pressure system. The criteria for this advisory vary from area to area.
An ice storm warning is a hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service in the United States which indicates that freezing rain produces a significant and possibly damaging accumulation of ice on surfaces. The criteria for this warning vary from state to state, but typically an ice storm warning will be issued any time more than 1⁄4 inch (6.4 mm) of ice at peak is expected to accumulate in an area, else a freezing rain or drizzle advisory is issued; in some areas, the criterion is 1⁄2 inch (13 mm) instead.
A heavy snow warning was a hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service (NWS) in the United States which indicates a high rate of snowfall was occurring or was forecast to occur. Generally, the warning was issued for snowfall rates of 6 inches (15 cm) or more in 12 hours, or 8 inches (20 cm) or more in 24 hours.
This article describes severe weather terminology used by the National Weather Service (NWS) in the United States. The NWS, a government agency operating as an arm of the National Oceanic and Atmospheric Administration (NOAA) branch of the United States Department of Commerce (DoC), defines precise meanings for nearly all of its weather terms.
A lake effect snow warning is a bulletin issued by the National Weather Service in the United States to warn of heavy snowfall accumulations that are imminent from convective snow generated by very cold airmass passing over unfrozen lakes. The criteria for amounts may vary significantly over different county warning areas. On October 2, 2017, some National Weather Service Forecast Offices discontinued issuing the Lake Effect Snow Warning, and consolidated it with the Winter Storm Warning. On October 15, 2018, the National Weather Service discontinued issuing Lake Effect Snow Warnings nationwide all together, and all offices consolidated it with the Winter Storm Warning. Lake effect snow warnings were reinstated for the 2019–20 winter season.
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.
It is very rare for snow to fall in the U.S. state of Florida, especially in the central and southern portions of the state. With the exception of the far northern areas of the state, most of the major cities in Florida have never recorded measurable snowfall, though trace amounts have been recorded, or flurries in the air observed few times each century. According to the National Weather Service, in the Florida Keys and Key West there is no known occurrence of snow flurries since the European colonization of the region more than 300 years ago. In Miami, Fort Lauderdale, and Palm Beach there has been only one known report of snow flurries observed in the air in more than 200 years; this occurred in January 1977. In any event, Miami, Fort Lauderdale, and Palm Beach have not seen snow flurries before or since this 1977 event.
The February 2007 North American blizzard was a massive winter storm that affected most of the eastern half of North America, starting on February 12, 2007 and peaking on Valentine's Day, February 14. The storm produced heavy snowfalls across the midwestern United States from Nebraska to Ohio and produced similar conditions across parts of the northeastern United States, and into Canada in Ontario, Quebec and New Brunswick. Significant sleet and freezing rain fell across the southern Ohio Valley and affected portions of the east coast of the United States, including the cities of Boston, Baltimore, Washington, D.C., New York City and Philadelphia.
A blizzard warning is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States, which indicates heavy snowfall accompanied by sustained winds or frequent gusts of 35 mph (56 km/h) or greater are forecast to occur for a minimum of three hours. A blizzard tends to reduce visibilities to 1⁄4 mile (400 m) or less.
A blizzard watch was a bulletin issued by the National Weather Service of the United States which meant winds greater than 35 miles per hour, mixed with falling or blowing snow, and visibilities of 1⁄4 mile (0.4 km) or less is forecast for a period of 3 hours or more. A blizzard watch was issued 12 to 48 hours before an expected blizzard event. As the forecast solidifies, a blizzard watch would be either downgraded to a winter storm warning or winter weather advisory for blowing snow or upgraded to a blizzard warning.
A freezing rain advisory was an advisory issued by the National Weather Service in the United States when freezing rain or freezing drizzle was expected to cause significant inconveniences, but did not meet warning criteria.
The January 2014 Gulf Coast winter storm was a somewhat rare winter storm that impacted the eastern and southeastern United States, as well as Mexico, most notably the Gulf Coast region, which rarely receives frozen precipitation, in late January 2014. The storm came during a period of very cold temperatures across much of the United States, bringing frigid temperatures as far south as the Gulf Coast. The Weather Channel Unofficially named it Winter Storm Leon.
The 2013–14 North American winter was one of the most significant for the United States, due in part to the breakdown of the polar vortex in November 2013, which allowed very cold air to travel down into the United States, leading to an extended period of very cold temperatures. The pattern continued mostly uninterrupted throughout the winter and numerous significant winter storms affected the Eastern United States, with the most notable one being a powerful winter storm that dumped ice and snow in the Southeastern United States and the Northeastern United States in mid-February. Most of the cold weather abated by the end of March, though a few winter storms did affect the Western United States towards the end of the winter.
The December 15–17, 2020 nor'easter was a powerful nor'easter that hammered the Northeastern United States and produced widespread swaths of over 1 foot (12 in) of snow in much of the region from December 15–17, 2020, ending a 1,000+ day high-impact snowstorm drought in much of the Mid-Atlantic and coastal New England regions. The system developed out of a weak area of low-pressure that first developed over the Central United States producing some snowfall before moving eastward, and by December 16, a new, dominant area of low pressure began to develop along the Southeast coast. This low steadily deepened as it moved along and impacted the Mid-Atlantic coastline, prompting several winter-related advisories and warnings for much of the Northeast.
The February 15–20, 2021 North American winter storm, also unofficially referred to as Winter Storm Viola, was a significant and widespread snow and ice storm across much of the United States, Northern Mexico, and Southern Canada. The system started out as a winter storm on the West Coast of the United States on February 15, later moving southeast into the Southern Plains and Deep South from February 16–17. It then moved into the Appalachian Mountains and Northeastern United States, before finally moving out to sea on February 20. The storm subsequently became a powerful low pressure system over the North Atlantic, before eventually dissipating on February 26.
The February 2022 North American winter storm was a widespread, damaging, and severe winter storm which affected a wide swath of much of the United States with widespread wintry precipitation; it spread from Texas northeast to Maine. Nineteen states in the U.S. were impacted by the system; more than 90 million people were in the storm's path. The winter storm was named Winter Storm Landon by The Weather Channel and was also referred to by other media outlets as the Groundhog Snowstorm, primarily due to the storm impacting on Groundhog Day.
