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Tornado Outbreak Sequence Of December 18–20, 1957
On December 18–20, 1957, a significant tornado outbreak sequence affected the southern Midwest and the South of the contiguous United States. The outbreak sequence began on the afternoon of December 18, when a low-pressure area approached the southern portions of Missouri and Illinois. Supercells developed and proceeded eastward at horizontal speeds of , yielding what was considered the most severe tornado outbreak in Illinois on record so late in the calendar year. Total losses in the state were estimated to fall within the range of $8–$10 million. Background At 6:00 a.m. CST (12:00 UTC) on December 18, 1957, a vigorous shortwave trough entered the Great Plains with a cold front moving east across Oklahoma and Kansas. A dissipating stationary front over Oklahoma underwent frontolysis and later redeveloped as a warm front which extended across central Illinois. By 3:00 pm. CST (21:00 UTC), surface dew points reached the low 60s ° F a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tornadoes Of 1957
This page documents the tornadoes and tornado outbreaks of 1957, primarily in the United States. Most tornadoes form in the U.S., although some events may take place internationally. Tornado statistics for older years like this often appear significantly lower than modern years due to fewer reports or confirmed tornadoes. Events 1957 was the most active tornado season on record at the time as multiple tornado outbreaks repeatedly hit the same areas. Texas was especially hard hit throughout the year. April and May both saw a record-breaking 200+ tornadoes with numerous outbreaks throughout the months. United States yearly total January There were 17 tornadoes confirmed in the US in January. January 21–22 A tornado outbreak sequence of 16 tornadoes struck the US. The outbreak started on January 21, when a rare and destructive F1 tornado moved through areas north of Schofield Barracks, Hawaii. The next day, a large, long-tracked .25 mile wide F2 tornado moved through St. Louis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Missouri
Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it borders Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas to the south and Oklahoma, Kansas, and Nebraska to the west. In the south are the Ozarks, a forested highland, providing timber, minerals, and recreation. At 1.5 billion years old, the St. Francois Mountains are among the oldest in the world. The Missouri River, after which the state is named, flows through the center and into the Mississippi River, which makes up the eastern border. With over six million residents, it is the List of U.S. states and territories by population, 19th-most populous state of the country. The largest urban areas are St. Louis, Kansas City, Missouri, Kansas City, Springfield, Missouri, Springfield, and Columbia, Missouri, Columbia. The Cap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TORRO Scale
The TORRO tornado intensity scale (or T-Scale) is a scale measuring tornado intensity between T0 and T11. It was proposed by Terence Meaden of the Tornado and Storm Research Organisation (TORRO), a meteorological organisation in the United Kingdom, as an extension of the Beaufort scale. History and derivation from Beaufort scale The scale was tested from 1972 to 1975 and was made public at a meeting of the Royal Meteorological Society in 1975. The scale sets T0 as the equivalent of 8 on the Beaufort scale and is related to the Beaufort scale (B), up to 12 on the Beaufort scale, by the formula: : ''B'' = 2 (''T'' + 4) and conversely: : ''T'' = ''B''/2 - 4 The Beaufort scale was first introduced in 1805, and in 1921 quantified. It expresses the wind speed as faster than v in the formula: : v = 0.837 ''B''3/2 m/s TORRO scale formula Most UK tornadoes are T6 or below with the strongest known UK tornado estimated as a T9 (the 1666 Lincolnshire tornado). For comparison, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontolysis
Frontolysis (also known as Frontal decay) in meteorology, is the dissipation or weakening of an atmospheric front. It is generally described as a decrease in temperature gradients between colliding air masses or can be caused by a shift in wind pattern. In contrary to areas of " Frontogenesis", the areas where air masses diverge are called areas of frontolysis. See also * Frontogenesis *Outflow boundary An outflow boundary, also known as a gust front, is a storm-scale or mesoscale meteorology, mesoscale boundary separating thunderstorm-cooled air (Outflow (meteorology), outflow) from the surrounding air; similar in effect to a cold front, with ... References Synoptic meteorology and weather {{Meteorology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stationary Front
A stationary front (or quasi-stationary front) is a weather front or transition zone between two air masses when each air mass is advancing into the other at speeds less than 5 knots (about 6 miles per hour or about 9 kilometers per hour) at the ground surface. These fronts are typically depicted on weather maps as a solid line with alternating blue spikes (pointing toward the warmer air) and red domes (facing the colder air). Development A stationary front may form when a cold or warm front slows down or grows over time from underlying surface temperature differences, like a coastal front. Winds on the cold air and warm air sides often flow nearly parallel to the stationary front, often in opposite directions along either side of the stationary front. A stationary front usually remains in the same area for hours to days and may undulate as atmospheric waves move eastward along the front. Stationary fronts may change into a cold or warm front, and may form one or more extratro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kansas
Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named after the Kansas River, in turn named after the Kaw people, Kansa people. Its List of capitals in the United States, capital is Topeka, Kansas, Topeka, and its List of cities in Kansas, most populous city is Wichita, Kansas, Wichita; however, the largest urban area is the bi-state Kansas City metropolitan area split between Kansas and Missouri. For thousands of years, what is now Kansas was home to numerous and diverse Plains Indians, Indigenous tribes. The first settlement of non-indigenous people in Kansas occurred in 1827 at Fort Leavenworth. The pace of settlement accelerated in the 1850s, in the midst of political wars over the Slavery in the United States, slavery debate. When it was officially opened to settlement by the U.S. governm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oklahoma
Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northeast, Arkansas to the east, New Mexico to the west, and Colorado to the northwest. Partially in the western extreme of the Upland South, it is the List of U.S. states and territories by area, 20th-most extensive and the List of U.S. states and territories by population, 28th-most populous of the 50 United States. Its residents are known as Oklahomans and its capital and largest city is Oklahoma City. The state's name is derived from the Choctaw language, Choctaw words , 'people' and , which translates as 'red'. Oklahoma is also known informally by its List of U.S. state and territory nicknames, nickname, "The Sooner State", in reference to the Sooners, American pioneer, American settlers who staked their claims in formerly American Indian-o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Front
A cold front is the leading edge of a cooler mass of air at ground level that replaces a warmer mass of air and lies within a pronounced surface Trough (meteorology), trough of Low-pressure area, low pressure. It often forms behind an extratropical cyclone (to the west in the Northern Hemisphere, to the east in the Southern Hemisphere, Southern), at the leading edge of its cold air Advection#Meteorology, advection pattern—known as the cyclone's dry "conveyor belt" flow. Temperature differences across the boundary can exceed from one side to the other. When enough moisture is present, rain can occur along the boundary. If there is significant Convective instability, instability along the boundary, a Squall line, narrow line of thunderstorms can form along the frontal zone. If instability is weak, a broad shield of rain can move in behind the Weather front, front, and evaporative cooling of the rain can increase the temperature difference across the front. Cold fronts are stronger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Plains
The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include the mixed grass prairie, the tallgrass prairie between the Great Lakes and Appalachian Plateau, and the Taiga Plains Ecozone, Taiga Plains and Boreal Plains Ecozone, Boreal Plains ecozones in Northern Canada. "Great Plains", or Western Plains, is also the ecoregion of the Great Plains or the western portion of the Great Plains, some of which in the farthest west is known as the High Plains. The Great Plains lie across both the Central United States and Western Canada, encompassing: *Most or all of the U.S. states of Kansas, Nebraska, and North Dakota, North and South Dakota; *Eastern parts of the U.S. states of Colorado, Montana, and Wyoming; *Parts of the U.S. states of New Mexico, Oklahoma, Texas; *Sometimes western parts of Iowa, Minnesot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure without a closed Isobar (meteorology), isobaric contour that would define it as a Low-pressure area, low pressure area. Since low pressure implies a low Geopotential height, height on a pressure surface, Valley, troughs and Ridge (meteorology), ridges refer to features in an identical sense as those on a topographic map. Troughs may be at the surface, or aloft, at altitude. Near-surface troughs sometimes mark a weather front associated with clouds, showers, and a wind direction shift. Upper-level troughs in the jet stream (as shown in diagram) reflect Cyclonic rotation, cyclonic filaments of vorticity. Their motion induces upper-level wind divergence, lifting and cooling the air ahead (downstream) of the trough and helping to produce cloudy and rain conditions there. Unlike fronts, there is not a universal symbol for a trough on a surface weather analysis chart. The weather charts in some countries or regions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortwave (meteorology)
A shortwave or shortwave trough is an embedded kink in the trough / ridge pattern. Its length scale is much smaller than that of and is embedded within longwaves, which are responsible for the largest scale (synoptic scale) weather systems. Shortwaves may be contained within or found ahead of longwaves and range from the mesoscale to the synoptic scale. Shortwaves are most frequently caused by either a cold pool or an upper level front. Shortwaves are commonly referred to as a vorticity maximum. Corresponding weather and effects Shortwaves are often associated with warm air advection (WAA) or cold air advection (CAA), which influence temperature. Due to the way they move the air around them and the way air moves away from them, shortwaves produce positive curvature vorticity and positive shear vorticity, respectively. Ahead of a shortwave there is large-scale lift due to divergence from positive vorticity advection (PVA). This lift often causes precipitation. In a capp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinated Universal Time
Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communication, navigation, scientific research, and commerce. UTC has been widely embraced by most countries and is the effective successor to Greenwich Mean Time (GMT) in everyday usage and common applications. In specialised domains such as scientific research, navigation, and timekeeping, other standards such as Universal Time, UT1 and International Atomic Time (TAI) are also used alongside UTC. UTC is based on TAI (International Atomic Time, abbreviated from its French name, ''temps atomique international''), which is a weighted average of hundreds of atomic clocks worldwide. UTC is within about one second of mean solar time at 0° longitude, the currently used prime meridian, and is not adjusted for daylight saving time. The coordination of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
