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1948 Tinker Air Force Base Tornadoes
The 1948 Tinker Air Force Base tornadoes were two tornadoes which struck Tinker Air Force Base in Oklahoma City, Oklahoma, on March 20 and 25, 1948. Both are estimated to have been equivalent to F3 in intensity on the modern Fujita scale of tornado intensity, which was not devised until 1971. The March 20 tornado was the costliest tornado in Oklahoma history at the time. On March 25, meteorologists at the base noticed the extreme similarity between the weather conditions of that day and March 20, and later in the day issued a "tornado forecast", which was verified when a tornado struck the base that evening. This was the first official tornado forecast, as well as the first successful tornado forecast, in recorded history. March 20 tornado Weather forecasting was still crude and prone to large errors in the era before weather satellites and computer modeling. Thunderstorms were not even in the forecast for the evening of March 20. However, around 9:30 pm storms were report ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal Corps, the USAF was established as a separate branch of the United States Armed Forces in 1947 with the enactment of the National Security Act of 1947. It is the second youngest branch of the United States Armed Forces and the fourth in order of precedence. The United States Air Force articulates its core missions as air supremacy, global integrated intelligence, surveillance and reconnaissance, rapid global mobility, global strike, and command and control. The United States Air Force is a military service branch organized within the Department of the Air Force, one of the three military departments of the Department of Defense. The Air Force through the Department of the Air Force is headed by the civilian Secretary of the Air Force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Saturday Evening Post
''The Saturday Evening Post'' is an American magazine, currently published six times a year. It was issued weekly under this title from 1897 until 1963, then every two weeks until 1969. From the 1920s to the 1960s, it was one of the most widely circulated and influential magazines within the American middle class, with fiction, non-fiction, cartoons and features that reached two million homes every week. The magazine declined in readership through the 1960s, and in 1969 ''The Saturday Evening Post'' folded for two years before being revived as a quarterly publication with an emphasis on medical articles in 1971. As of the late 2000s, ''The Saturday Evening Post'' is published six times a year by the Saturday Evening Post Society, which purchased the magazine in 1982. The magazine was redesigned in 2013. History Rise ''The Saturday Evening Post'' was first published in 1821 in the same printing shop at 53 Market Street in Philadelphia where the Benjamin Franklin-founded ''Pennsyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miller Classification
The Miller Classification is a technique that meteorologists use to classify nor'easters. The system splits nor'easters into five categories: Miller A, Miller B, Miller C, Miller D, and Miller E; the classification system initially started out with the first two categories. The system was derived by meteorologist and researcher J.E. Miller in 1946, (not to be confused with R.C. Miller, the Air Force meteorologist who, in 1948, made the world's first successful tornado forecast). Background A nor'easter is a macro-scale extratropical cyclone that travels along the East Coast of the United States and Atlantic Canada. The cyclones are called nor'easters because the winds over the coastal area are typically from the northeast. These storms may occur at any time of year, but are most frequent and severe between September and April. Nor'easters usually develop in the latitudes between Georgia and New Jersey, within 100 miles east or west of the coastline. These storms track north-nor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synoptic Scale Meteorology
The synoptic scale in meteorology (also known as large scale or cyclonic scale) is a horizontal length scale of the order of 1000 kilometers (about 620 miles) or more. This corresponds to a horizontal scale typical of mid-latitude depressions (e.g., extratropical cyclones). Most high- and low-pressure areas seen on weather maps (such as surface weather analyses) are synoptic-scale systems, driven by the location of Rossby waves in their respective hemisphere. Low-pressure areas and their related frontal zones occur on the leading edge of a trough within the Rossby wave pattern, while high-pressure areas form on the back edge of the trough. Most precipitation areas occur near frontal zones. The word ''synoptic'' is derived from the Greek word ('), meaning ''seen together''. The Navier–Stokes equations applied to atmospheric motion can be simplified by scale analysis in the synoptic scale. It can be shown that the main terms in horizontal equations are Coriolis force and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Bureau
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 te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercell
A supercell is a thunderstorm characterized by the presence of a mesocyclone: a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms (supercell, squall line, multi-cell, and single-cell), supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to away. They tend to last 2–4 hours. Supercells are often put into three classification types: classic (Normal precipitation level), low-precipitation (LP), and high-precipitation (HP). LP supercells are usually found in climates that are more arid, such as the high plains of the United States, and HP supercells are most often found in moist climates. Supercells can occur anywhere in the world under the right pre-existing weather conditions, but they are most common in the Great Plains of the United State ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bomb Shelter
A bomb shelter is a structure designed to provide protection against the effects of a bomb. Types of shelter Different kinds of bomb shelters are configured to protect against different kinds of attack and strengths of hostile explosives. Air raid shelter An air raid shelter is a structure built to protect against bomber planes dropping bombs over a large area. These were commonly seen during World War II, such as the "Anderson shelters" of the United Kingdom. Fallout shelter A fallout shelter is a shelter designed specifically for a nuclear war, with thick walls made from materials intended to block the radiation from fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War. A blast shelter protects against more conventional bomb blasts. Its main purpose is to protect from shock waves and overpressure and also from earthquake. Bunker While these forms of bomb shelters are equally amenable to ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumulonimbus Cloud
Cumulonimbus (from Latin ''cumulus'', "heaped" and ''nimbus'', "rainstorm") is a dense, towering vertical cloud, typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful buoyant air currents. Above the lower portions of the cumulonimbus the water vapor becomes ice crystals, such as snow and graupel, the interaction of which can lead to hail and to lightning formation, respectively. When occurring as a thunderstorm these clouds may be referred to as thunderheads. Cumulonimbus can form alone, in clusters, or along squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes, hazardous winds, and large hailstones. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell. Cumulonimbus is abbreviated Cb. Appearance Towering cumulonimbus clouds are typically accompanied by smaller cumulus clouds. The cumulonimbus bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Station
A weather station is a facility, either on land or sea, with instruments and equipment for measuring atmospheric conditions to provide information for weather forecasts and to study the weather and climate. The measurements taken include temperature, atmospheric pressure, humidity, wind speed, wind direction, and precipitation amounts. Wind measurements are taken with as few other obstructions as possible, while temperature and humidity measurements are kept free from direct solar radiation, or insolation. Manual observations are taken at least once daily, while automated measurements are taken at least once an hour. Weather conditions out at sea are taken by ships and buoys, which measure slightly different meteorological quantities such as sea surface temperature (SST), wave height, and wave period. Drifting weather buoys outnumber their moored versions by a significant amount. Weather instruments Typical weather stations have the following instruments: * Thermometer for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squall Line
A squall line, or more accurately a quasi-linear convective system (QLCS), is a line of thunderstorms, often forming along or ahead of a cold front. In the early 20th century, the term was used as a synonym for cold front (which often are accompanied by abrupt and gusty wind shifts). Linear thunderstorm structures often contain heavy precipitation, hail, frequent lightning, strong straight-line winds, and occasionally tornadoes or waterspouts. Particularly strong straight-line winds can occur where the linear structure forms into the shape of a bow echo. Tornadoes can occur along waves within a line echo wave pattern (LEWP), where mesoscale low-pressure areas are present. Some bow echoes can grow to become derechos as they move swiftly across a large area. On the back edge of the rainband associated with mature squall lines, a wake low can be present, on very rare occasions associated with a heat burst. Theory Polar front theory was developed by Jacob Bjerknes, derived from a dens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Radar
Weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.). Modern weather radars are mostly pulse-Doppler radars, capable of detecting the motion of rain droplets in addition to the intensity of the precipitation. Both types of data can be analyzed to determine the structure of storms and their potential to cause severe weather. During World War II, radar operators discovered that weather was causing echoes on their screen, masking potential enemy targets. Techniques were developed to filter them, but scientists began to study the phenomenon. Soon after the war, surplus radars were used to detect precipitation. Since then, weather radar has evolved on its own and is now used by national weather services, research departments in universities, and in television stations' weather departments. Raw images are routinely used and speciali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tornado Watch
A tornado watch ( SAME code: TOA) is a severe weather watch product issued by national weather forecasting agencies when meteorological conditions are favorable for the development of severe thunderstorms capable of producing tornadoes. In addition to the potential for tornado development, thunderstorms that develop within the watch area may contain large hail, straight-line winds, intense rainfall and/or flooding that pose a similar damage risk as the attendant tornado threat. A tornado watch does not mean a tornado is active or ''will'' appear, just that favorable conditions increases the likelihood of such happening. A watch must not be confused with a tornado warning. Definition A ''tornado watch'' indicates that atmospheric conditions observed in and close to the watch area have created a significant risk for the development and intensification of severe convective thunderstorms capable of producing tornadoes, and are normally issued in advance of the onset of severe weathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
