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Significant Weather Advisory
A significant weather advisory was a hazardous weather statement issued by certain Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public of thunderstorm activity that is below designated severe criteria for and/or is not expected to produce severe weather. The title assigned to the advisory—alternately titled "significant weather alert" or referenced by its originating product, " special weather statement"—varied by the issuing WFO. Created in April 2002 as an unofficial special weather statement sub-product, the advisory was issued when trained storm spotters or Doppler weather radar indicate that a sub-severe thunderstorm is producing or will soon produce hail or strong winds below NWS-determined severe weather warning criteria. Should conditions favor intensification or severe weather approach the alerted area, a warning may be required. While intense lightning or rainfall caused by the thunderstorm did not merit an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Weather Service
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 1890 until it adopted its current name in 1970. The NWS performs its primary task through a collection of national and regional centers, and 122 local Weather Forecast Offices (WFOs). As the NWS is an agency of the U.S. federal government, most of its products are in the public domain and available free of charge. History Calls for the creation of a government weather bureau began as early as 1844, when the electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Severe Thunderstorm Warning
A severe thunderstorm warning ( SAME code: SVR) is a severe weather warning product issued by regional offices of weather forecasting agencies throughout the world to alert the public that severe thunderstorms are imminent or occurring. A severe thunderstorm warning is issued when Doppler weather radar, trained storm spotters or local emergency management personnel indicate that a thunderstorm is producing large hail and high winds capable of causing significant damage, and is expected to continue producing severe weather along the storm's projected track. Flooding is also sometimes caused by torrential rainfall produced by a thunderstorm. (In these cases, a flood advisory or flash flood warning may be issued to alert the public of the flooding threat.) Definition A severe thunderstorm warning indicates the warned area is in impending danger from hail or wind speeds meeting warning criteria as well as from lightning and hydrological impacts associated with the storm cell. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Area Message Encoding
Specific Area Message Encoding (SAME) is a protocol used for framing and classification of broadcast emergency warning messages. It was developed by the United States National Weather Service for use on its NOAA Weather Radio (NWR) network, and was later adopted by the Federal Communications Commission for the Emergency Alert System, then subsequently by Environment Canada for use on its Weatheradio Canada service. It is also used to set off receivers in Mexico City and surrounding areas as part of the Mexican Seismic Alert System (SASMEX). History From the 1960s to the 1980s, a special feature of the NOAA Weather Radio (NWR) system was the transmission of a single attention tone prior to the broadcast of any message alerting the general public of significant weather events. This became known as the Warning Alarm Tone (WAT). Although it served NWR well, there were many drawbacks. Without staff at media facilities to manually evaluate the need to rebroadcast an NWR message ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emergency Alert System
The Emergency Alert System (EAS) is a national warning system in the United States designed to allow authorized officials to broadcast emergency alerts and warning messages to the public via cable, satellite, or broadcast television, and both AM/ FM and satellite radio. The EAS became operational on January 1, 1997, after being approved by the Federal Communications Commission (FCC) in November 1994, replacing the Emergency Broadcast System (EBS). Its main improvement over the EBS, and perhaps its most distinctive feature, is its application of a digitally encoded audio signal known as Specific Area Message Encoding (SAME), which is responsible for the "screeching" or "chirping" sounds at the start and end of each message. This signal encodes locations an alert applies to, useful for specialized encoding and decoding equipment at broadcasting stations to automatically filter alert messages that do not apply to the area and to relay messages that do. Like the EBS, the syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landspout
__NOTOC__ Landspout is a term created by atmospheric scientist Howard B. Bluestein in 1985 for a kind of tornado not associated with a mesocyclone. The ''Glossary of Meteorology'' defines a landspout as : "Colloquial expression describing tornadoes occurring with a parent cloud in its growth stage and with its vorticity originating in the boundary layer. : The parent cloud does not contain a preexisting mid-level mesocyclone. The landspout was so named because it looks like "a weak Florida Keys waterspout over land." Landspouts are typically weaker than mesocyclone associated tornadoes spawned within supercell thunderstorms, in which the strongest tornadoes form. Characteristics Landspouts are a type of tornado that forms during the growth stage of a cumulus congestus or occasionally a cumulonimbus cloud when an updraft stretches boundary layer vorticity upward into a vertical axis and tightens it into a strong vortex. These generally are smaller and weaker than supercell to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterspout
A waterspout is an intense columnar vortex (usually appearing as a funnel-shaped cloud) that occurs over a body of water. Some are connected to a cumulus congestus cloud, some to a cumuliform cloud and some to a cumulonimbus cloud. In the common form, it is a non- supercell tornado over water having a five-part life cycle: formation of a dark spot on the water surface, spiral pattern on the water surface, formation of a spray ring, development of the visible condensation funnel, and ultimately, decay. Most waterspouts do not suck up water; they are small and weak rotating columns of air over water. Although they are most often weaker than their land counterparts, stronger versions spawned by mesocyclones do occur. While waterspouts form mostly in tropical and subtropical areas, other areas also report waterspouts, including Europe, Western Asia (the Middle East), Australia, New Zealand, the Great Lakes, Antarctica, and on rare occasions, the Great Salt Lake, among other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First Warning
First Warning is the name of a severe weather warning system designed for broadcast television stations, typically those in the United States. A weather advisory product based on First Warning, called ''First Alert'', is an automated version of this product, which has come into widespread use by television stations and is marketed under different names depending on the graphics service vendor. Both products are typically used by television stations that have an in-house news and weather operation, although some television stations that do not broadcast news at all or have their newscasts produced by another station in their market may use the system as well. Overview First Warning was created in 1990 by Gary England, then the chief meteorologist of CBS affiliate KWTV in Oklahoma City, Oklahoma (a city which historically has had the highest number of tornado strikes of any U.S. city since tornado records began to be logged in 1890), and went into use in the spring of 1991. The s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
County (United States)
In the United States, a county is an administrative or political subdivision of a state that consists of a geographic region with specific boundaries and usually some level of governmental authority. The term " county" is used in 48 states, while Louisiana and Alaska have functionally equivalent subdivisions called parishes and boroughs, respectively. The specific governmental powers of counties vary widely between the states, with many providing some level of services to civil townships, municipalities, and unincorporated areas. Certain municipalities are in multiple counties; New York City is uniquely partitioned into five counties, referred to at the city government level as boroughs. Some municipalities have consolidated with their county government to form consolidated city-counties, or have been legally separated from counties altogether to form independent cities. Conversely, those counties in Connecticut, Rhode Island, eight of Massachusetts's 14 counties, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storm Prediction Center
The Storm Prediction Center (SPC) is a US government agency that is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service (NWS), which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the United States Department of Commerce (DoC). Headquartered at the National Weather Center in Norman, Oklahoma, the Storm Prediction Center is tasked with forecasting the risk of severe thunderstorms and tornadoes in the contiguous United States. It issues convective outlooks, mesoscale discussions, and watches as a part of this process. Convective outlooks are issued for the following eight days (issued separately for Day 1, Day 2, Day 3, and Days 4–8), and detail the risk of severe thunderstorms and tornadoes during the given forecast period, although tornado, hail and wind details are only available for Days 1 and 2. Day 3, as well as 4–8 use a probabilistic scale, dete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polygon
In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed ''polygonal chain'' (or ''polygonal circuit''). The bounded plane region, the bounding circuit, or the two together, may be called a polygon. The segments of a polygonal circuit are called its '' edges'' or ''sides''. The points where two edges meet are the polygon's '' vertices'' (singular: vertex) or ''corners''. The interior of a solid polygon is sometimes called its ''body''. An ''n''-gon is a polygon with ''n'' sides; for example, a triangle is a 3-gon. A simple polygon is one which does not intersect itself. Mathematicians are often concerned only with the bounding polygonal chains of simple polygons and they often define a polygon accordingly. A polygonal boundary may be allowed to cross over itself, creating star polygons and other self-intersecting polygons. A polygon is a 2-dimensional example of the more general polytope in any num ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birmingham, Alabama
Birmingham ( ) is a city in the north central region of the U.S. state of Alabama. Birmingham is the seat of Jefferson County, Alabama's most populous county. As of the 2021 census estimates, Birmingham had a population of 197,575, down 1% from the 2020 Census, making it Alabama's third-most populous city after Huntsville and Montgomery. The broader Birmingham metropolitan area had a 2020 population of 1,115,289, and is the largest metropolitan area in Alabama as well as the 50th-most populous in the United States. Birmingham serves as an important regional hub and is associated with the Deep South, Piedmont, and Appalachian regions of the nation. Birmingham was founded in 1871, during the post- Civil War Reconstruction period, through the merger of three pre-existing farm towns, notably, Elyton. It grew from there, annexing many more of its smaller neighbors, into an industrial and railroad transportation center with a focus on mining, the iron and steel industry, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flash Flood Warning
A flash flood warning ( SAME code: FFW) is an hazardous weather statement issued by national weather forecasting agencies throughout the world to alert the public that a flash flood is imminent or occurring in the warned area. A flash flood is a sudden, violent flood after a heavy rain, or occasionally after a dam break. Rainfall intensity and duration, topography, soil conditions, and ground cover contribute to flash flooding. Most flash floods occur when there is a heavy amount of precipitation falling in an area and that water is then channeled through streams or narrow gullies. Flash floods may take minutes or hours to develop. It is possible to experience a flash flood without witnessing any rain. Flash flood alerts There are two types of alerts for flash floods which are issued by the National Weather Service. One is a flash flood watch, which means that conditions are favorable for flash flooding, and the other is a flash flood warning, meaning that a flash flood is occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
