A forecast region is a unique

geographical area In geography, regions, otherwise referred to as areas, zones, lands or territories, are portions of the Earth's surface that are broadly divided by physical characteristics ( physical geography), human impact characteristics ( human geography), ...

for which individual

weather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmo ...

reports are issued.

Canada

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

, the

Meteorological Service Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture, ...

divides the country into several forecast regions for the purpose of issuing routine text forecasts and weather warnings, as Canada's provinces and territories do not use a common second-level

administrative division Administrative divisions (also administrative units, administrative regions, subnational entities, or constituent states, as well as many similar generic terms) are geographical areas into which a particular independent sovereign state is divi ...

scheme similar to the division of states into

counties A county () is a geographic region of a country used for administrative or other purposesL. Brookes (ed.) '' Chambers Dictionary''. Edinburgh: Chambers Harrap Publishers Ltd, 2005. in some nations. The term is derived from the Old French denoti ...

and

parish A parish is a territorial entity in many Christianity, Christian denominations, constituting a division within a diocese. A parish is under the pastoral care and clerical jurisdiction of a priest#Christianity, priest, often termed a parish pries ...

es in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. Due to the localized nature of some weather phenomena, such as

freezing rain Freezing rain is rain maintained at temperatures below melting point, freezing by the ambient air mass that causes freezing on contact with surfaces. Unlike rain and snow mixed, a mixture of rain and snow or ice pellets, freezing rain is made en ...

storms and

tornado A tornado is a violently rotating column of air that is in contact with the surface of Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, although the ...

es, some forecast regions that have been found to be more prone to such phenomena are further divided into sub-regions, especially in the

Prairie provinces The Canadian Prairies (usually referred to as simply the Prairies in Canada) is a region in Western Canada. It includes the Canadian portion of the Great Plains and the Prairie provinces, namely Alberta, Saskatchewan, and Manitoba. These provin ...

. Parts of Northern British Columbia, Northern Quebec, Labrador, and the territories do not belong to any forecast region, owing to the lack of any significant population in those areas. With the implementation of

Specific Area Message Encoding Specific Area Message Encoding (SAME) is a Communications protocol, protocol used for framing and classification of broadcasting Emergency population warning, emergency warning messages. It was developed by the United States National Weather Serv ...

into the

Weatheradio Canada Weatheradio Canada () is a Canadian weather radio network owned and operated by Environment and Climate Change Canada's Meteorological Service of Canada division. It is one of the two weather radio systems across North America along with the NOAA ...

service in 2007, each forecast region and sub-region has been given a unique six-digit code known as a Canadian Location Code, or CLC. These codes are programmed into SAME-capable

weather radio A weather radio is a specialized radio receiver that is designed to receive a public broadcast service, typically from government-owned radio stations, dedicated to broadcasting weather forecasts and reports on a continual basis, with the routine w ...

receivers the same way FIPS county codes are programmed into receivers in the United States, enabling them to only activate and sound an alert when the MSC issues weather warnings for the forecast regions that have their codes programmed into the receivers. Outside of

Nunavut Nunavut is the largest and northernmost Provinces and territories of Canada#Territories, territory of Canada. It was separated officially from the Northwest Territories on April 1, 1999, via the ''Nunavut Act'' and the Nunavut Land Claims Agr ...

and the

Northwest Territories The Northwest Territories is a federal Provinces and territories of Canada, territory of Canada. At a land area of approximately and a 2021 census population of 41,070, it is the second-largest and the most populous of Provinces and territorie ...

, CLCs are assigned using the format 0''paabb'', where 0 is a constant, ''p'' is a province or provincial or territorial grouping, ''aa'' refers to a specific forecast region, and ''bb'', if nonzero, refers to a sub-region. In Nunavut and the Northwest Territories, where population densities are much lower than elsewhere in the country, the format is 09''aaa''0, where ''aaa'' refers to the forecast region. On the water, CLCs are assigned using the format 00''aaab'', where ''aaa'' refers to the forecast region, and ''b'', if nonzero, refers to a sub-region. CLCs are also assigned to the areas of international waters for which Canada issues maritime navigation and weather warnings. For specific types of warnings, such as air quality alerts, coastal flood warnings and tsunami warnings, CLCs of the format 0''p''0''aaa'' have been assigned.

List of forecast regions by province and territory

If viewing this page online, each forecast region name is linked to a page on the MSC's website detailing all watches and warnings currently in effect for that region.

List of marine forecast regions

If viewing this page online, each marine forecast region entry is linked to a page on the MSC's website with the marine forecast and any warnings in effect for that region.

List of air quality monitoring stations

Maritimes

Newfoundland and Labrador

Quebec

Ontario

Manitoba

Saskatchewan

Alberta

British Columbia

Territories

List of coastal and inland lacustrine flood warning regions

Maritimes

Newfoundland and Labrador

Quebec

Ontario

Prairies

British Columbia

Territories

List of tsunami warning regions

MSC Forecast Location Polygon Package version 6.11.0

Meteorological Service of Canada The Meteorological Service of Canada (MSC; ) is a branch of Environment and Climate Change Canada, which primarily provides public meteorological information and weather forecasts and warnings of severe weather and other environmental hazards. ...

. Retrieved 14 December 2024.

United States

In the U.S., the

National Weather Service The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weathe ...

uses

zone forecast Zone, Zones or The Zone may refer to: Places Military zones * Zone, any of the divisions of France during the World War II German occupation * Zone, any of the divisions of Germany during the post-World War II Allied occupation * Korean Demilit ...

s, where generally each county is a zone. For counties near the ocean, there are normally two zones: coastal and inland. The same is true for

that are part

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher t ...

ous and part

lowland Upland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Definitions Upland and lowland are portions of a ...

, or for counties that are quite long. This older system is not used for warnings, which are based on FIPS codes (two digits for the state, three for the county or

independent city An independent city or independent town is a city or town that does not form part of another general-purpose local government entity (such as a province). Historical precursors In the Holy Roman Empire, and to a degree in its successor states ...

), with the initial digit being for optional sub-county divisions. Both of these are becoming less important with the advent of

point forecast A point is a small dot or the sharp tip of something. Point or points may refer to: Mathematics * Point (geometry), an entity that has a location in space or on a plane, but has no extent; more generally, an element of some abstract topologica ...

s, and

polygon In geometry, a polygon () is a plane figure made up of line segments connected to form a closed polygonal chain. The segments of a closed polygonal chain are called its '' edges'' or ''sides''. The points where two edges meet are the polygon ...

al warning boxes based on lines drawn between

geographic coordinate A geographic coordinate system (GCS) is a spherical or geodetic coordinate system for measuring and communicating positions directly on Earth as latitude and longitude. It is the simplest, oldest, and most widely used type of the various ...

points. The coordinates of such points are listed at the end of each warning. The term county warning area is also used to indicate the area of responsibility for each NWS forecast office. The forecast area is usually synonymous with the

broadcast range A broadcast range (also listening range or listening area for radio, or viewing range or viewing area for television) is the service area that a broadcast station or other transmission covers via radio waves (or possibly infrared light, which i ...

of all

NOAA Weather Radio NOAA Weather Radio (NWR), also known as NOAA Weather Radio All Hazards, is an automated 24-hour network of Very high frequency, VHF Frequency modulation, FM weather radio stations in the United States which broadcast weather information direct ...

station Station may refer to: Agriculture * Station (Australian agriculture), a large Australian landholding used for livestock production * Station (New Zealand agriculture), a large New Zealand farm used for grazing by sheep and cattle ** Cattle statio ...

s programmed from any particular office, though the

broadcast callsign Broadcast call signs are call signs assigned as unique identifiers to radio stations and television stations. While broadcast radio stations will often brand themselves with plain-text names, identities such as " cool FM", " rock 105" or "the AB ...

followed by "listening area" is often used.

References

{{reflist Weather forecasting