Central Texas Tornado Outbreak
A deadly tornado outbreak occurred in Central Texas during the afternoon and evening of May 27, 1997, in conjunction with a southwestward-moving cluster of supercell thunderstorms. These storms produced 20 tornadoes, mainly along the Interstate 35 corridor from northeast of Waco to north of San Antonio. The strongest tornado was an F5 tornado that leveled parts of Jarrell, killing 27 people and injuring 12 others. Overall, 30 people were killed and 33 others were hospitalized by the severe weather. Although the atmospheric conditions enabling the event were forecast to be conducive for strong winds and large hail, forecasters did not initially anticipate as much of a risk of strong tornadoes due to the lack of substantial wind shear over the region. Instead, the coalescence of several weather features—including a cold front, a dry line, and a gravity wave—provided locally favorable conditions for rotating thunderstorms and the formation of ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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 of low pressure. It often forms behind an extratropical cyclone (to the west in the Northern Hemisphere, to the east in the Southern), at the leading edge of its cold air 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 instability along the boundary, a narrow line of thunderstorms can form along the frontal zone. If instability is weak, a broad shield of rain can move in behind the front, and evaporative cooling of the rain can increase the temperature difference across the front. Cold fronts are stronger in the fall and spring transition seasons and are weakest during the summer. Development of cold fronts A cold front occurs wh ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Troposphere
The troposphere is the first and lowest layer of the atmosphere of the Earth, and contains 75% of the total mass of the planetary atmosphere, 99% of the total mass of water vapour and aerosols, and is where most weather phenomena occur. From the planetary surface of the Earth, the average height of the troposphere is in the tropics; in the middle latitudes; and in the high latitudes of the polar regions in winter; thus the average height of the troposphere is . The term ''troposphere'' derives from the Greek words ''tropos'' (rotating) and '' sphaira'' (sphere) indicating that rotational turbulence mixes the layers of air and so determines the structure and the phenomena of the troposphere. The rotational friction of the troposphere against the planetary surface affects the flow of the air, and so forms the planetary boundary layer (PBL) that varies in height from hundreds of meters up to . The measures of the PBL vary according to the latitude, the landform, and th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure without a closed isobaric contour that would define it as a low pressure area. Since low pressure implies a low height on a pressure surface, troughs and ridges refer to features in an identical sense as those on a topographic map. Troughs may be at the surface, or aloft. 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 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 mark troughs by a line. In the United States, a trough may be marked as a dashed line or bold line. In the UK, Hong Kong ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lake Travis
Lake Travis is a reservoir on the Colorado River in central Texas in the United States. Serving principally as a flood-control reservoir, Lake Travis' historical minimum to maximum water height change is nearly 100 feet. In 2018 alone, it saw a 20-foot depth increase within a single 24-hour period of time. With 30 square miles of surface area, Lake Travis has the largest storage capacity of the seven reservoirs known as the Highland Lakes, and stretches 65 miles (105 km) upriver from western Travis County (near Lago Vista, Texas) in a highly serpentine course into southern Burnet County to Max Starcke Dam, southwest of the town of Marble Falls. Besides being used for flood control and as a water supply, the lake is also used for electrical power generation and recreation. The Pedernales River, a major tributary of the Colorado River, flows into the lake from southwestern Travis County. History Creation The reservoir was formed in 1942 by the construction of Man ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cedar Park, Texas
Cedar Park is a city and a major suburb of Austin in the state of Texas, approximately to the north-west of the center of Austin. According to the 2020 U.S. Census, the city's population was 77,595. History Before the arrival of European settlers in the 19th century, the Cedar Park area was inhabited by Native American tribes including the Tonkawa, the Lipan Apache, and the Comanche. A paleo-American archaeological site (named the Wilson-Leonard site) was discovered in Cedar Park in 1983 that showed evidence of continual habitation of the area since circa 5000 BC. In the mid-19th century the community was known as Running Brushy, named after a spring that formed the headwaters of a creek of the same name. In 1873 George and Harriet Cluck, after having run cattle up the Chisholm Trail for many years, bought of land that included the Running Brushy spring. Their ranch formed the core of the community that would one day become Cedar Park. Ten years later, the railroad came thro ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Frio County, Texas
Frio County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 18,385. The county seat is Pearsall. The county was created in 1858 and later organized in 1871. Frio is named for the Frio River, whose name is Spanish for "cold". Geography According to the U.S. Census Bureau, the county has a total area of , of which are land and (0.07%) is covered by water. Major highways * Interstate 35 * U.S. Highway 57 * State Highway 85 * State Highway 173 Adjacent counties * Medina County (north) * Atascosa County (east) * McMullen County (southeast) * La Salle County (south) * Dimmit County (southwest) * Zavala County (west) * Uvalde County (northwest) Demographics As of the 2020 United States census, there were 18,385 people, 4,673 households, and 3,306 families residing in the county. As of the census of 2000, 16,252 people, 4,743 households, and 3,642 families resided in the county. The population density was 14 peop ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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McLennan County, Texas
McLennan County is a County (United States), county located on the Edwards Plateau in Central Texas. As of the 2020 United States Census, 2020 census, its population was 260,579 . Its county seat and largest city is Waco, Texas, Waco. The U.S. census 2021 county population estimate is 263,115. The county is named for Neil McLennan, an early Scottish settler who worked to push back the Indians in early Texas. McLennan County is included in the Waco Waco metropolitan area, Metropolitan Statistical Area. History McLennan County was created by the Texas Legislature in 1850 out of Milam County. The county seat, Waco, had been founded as an outpost of the Texas Ranger Division, Texas Rangers. It was laid out by George B. Erath, and was known by 1850 as Waco Village. In the 1880s, pharmacist Charles Alderton developed the carbonated beverage that became known as Dr Pepper. The Dr Pepper business was headquartered in Waco, until it moved to Dallas, Texas. Waco is also home to the D ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bordered by the state of Texas to the west, Arkansas to the north, Mississippi to the east, and the Gulf of Mexico to the south. A large part of its eastern boundary is demarcated by the Mississippi River. Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska and its boroughs). The state's capital is Baton Rouge, and its largest city is New Orleans, with a population of roughly 383,000 people. Some Louisiana urban environments have a multicultural, multilingual heritage, being so strongly influenced by a mixture of 18th century Louisiana French, Dominican Creole, Spanish, French Canadian, Acadi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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East Texas
East Texas is a broadly defined cultural, geographic, and ecological region in the eastern part of the U.S. state of Texas that comprises most of 41 counties. It is primarily divided into Northeast and Southeast Texas. Most of the region consists of the Piney Woods ecoregion. East Texas can sometimes be defined only as the Piney Woods. At the fringes, towards Central Texas, the forests expand outward toward sparser trees and eventually into open plains. According to the ''Handbook of Texas'', the East Texas area "may be separated from the rest of Texas roughly by a line extending from the Red River in north-central Lamar County southwestward to east-central Limestone County and then southeastward towards eastern Galveston Bay". Most sources separate the Gulf Coast area into a separate region. Another popular, somewhat simpler, definition defines East Texas as the region between the Trinity River, north and east of Houston (or sometimes Interstate 45, when defining generou ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |