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September 1921 San Antonio Floods
In early September 1921, the remnants of a Category 1 hurricane brought damaging floods to areas of Mexico and the U.S. state of Texas, particularly in the San Antonio region. On September 4, a tropical cyclone developed in the southwestern Gulf of Mexico near the Bay of Campeche. Moving slowly in a general westward direction, the disturbance reached hurricane intensity on September 7 prior to making landfall south of Tampico, Mexico the following day. The storm weakened over land, and lost cyclonic characteristics later that day. However, a nearby high-pressure area forced the remnants of the system northward into Texas. Due to an orographic lifting effect, the remnants were able to produce torrential and record rainfall over the state. Precipitation peaked over Central Texas, where the highest rainfall amount measured was 40 in (1,016 mm) near Thrall, Texas; this was the fourth-highest tropical cyclone-related rainfall total in Texas sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Weather Analysis
Surface weather analysis is a special type of weather map that provides a view of weather elements over a geographical area at a specified time based on information from ground-based weather stations. Weather maps are created by plotting or tracing the values of relevant quantities such as sea level pressure, temperature, and cloud cover onto a geographical map to help find synoptic scale features such as weather fronts. The first weather maps in the 19th century were drawn well after the fact to help devise a theory on storm systems.Eric R. MillerAmerican Pioneers in Meteorology.Retrieved on 2007-04-18. After the advent of the telegraph, simultaneous surface weather observations became possible for the first time, and beginning in the late 1840s, the Smithsonian Institution became the first organization to draw real-time surface analyses. Use of surface analyses began first in the United States, spreading worldwide during the 1870s. Use of the Norwegian cyclone model for front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williamson County, Texas
Williamson County (sometimes abbreviated as "Wilco") is a county in the U.S. state of Texas. As of the 2020 census, its population was 609,017. Its county seat is Georgetown. The county is named for Robert McAlpin Williamson (1804?–1859), a community leader and a veteran of the Battle of San Jacinto. Williamson County is part of the Austin-Round Rock-Georgetown metropolitan statistical area. It was included with Austin in the Best Cities to Live in for 2009 by the Milken Institute. It is on both the Edwards Plateau to the west, rocky terrain and hills, and Texas Blackland Prairies in the east, rich, fertile farming land. The two areas are roughly bisected by Interstate 35. History Prehistoric Much of Williamson County has been the site of human habitation for at least 11,200 years. The earliest known inhabitants of the area lived during the late Pleistocene (Ice Age), and are linked to the Clovis culture around 9,200 BC based on evidence found at Bell County's much-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HURDAT
The Hurricane Databases (HURDAT), managed by the National Hurricane Center, are two separate databases that contain details on tropical cyclones, that have occurred within the Atlantic Ocean and Eastern Pacific Ocean since 1851 and 1949 respectively. The Eastern Pacific database was originally compiled at the NHC during 1976, to help with the initialization with two tropical cyclone forecast models. Initially tracks for the Central Pacific region and tracks for tropical depressions, that did not develop into tropical storms or hurricanes were not included within the database. Over the next few years tracks were archived best track data from the Eastern Pacific Hurricane Center (EPHC) were archived by the NHC on an annual basis. During 1982 the NHC started to include data on Central Pacific tropical storms and hurricanes within the database, before they took over the responsibility for issuing advisories during 1988. The format of the Eastern Pacific database was subsequently signi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximum Sustained Wind
The maximum sustained wind associated with a tropical cyclone is a common indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are determined via their sampling and averaging the sampled results over a period of time. Wind measuring has been standardized globally to reflect the winds at above the Earth's surface, and the maximum sustained wind represents the highest average wind over either a one-minute (US) or ten-minute time span (see the definition, below), anywhere within the tropical cyclone. Surface winds are highly variable due to friction between the atmosphere and the Earth's surface, as well as near hills and mountains over land. Over the ocean, satellite imagery determines the value of the maximum sustained winds within a tropical cyclone. Land, ship, aircraft reconnaissance observations, and radar imagery can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Storm
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane (), typhoon (), tropical storm, cyclonic storm, tropical depression, or simply cyclone. A hurricane is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean, South Pacific, or (rarely) South Atlantic, comparable storms are referred to simply as "tropical cyclones", and such storms in the Indian Ocean can also be called "severe cyclonic storms". "Tropical" refers to the geographical origin of these systems, which form almost exclusively over tropical seas. "Cyclone" refers to their winds moving in a circle, whirling round t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inches Of Mercury
Inch of mercury (inHg and ″Hg) is a non- SI unit of measurement for pressure. It is used for barometric pressure in weather reports, refrigeration and aviation in the United States. It is the pressure exerted by a column of mercury in height at the standard acceleration of gravity. Conversion to metric units depends on the temperature of mercury, and hence its density; typical conversion factors are: In older literature, an "inch of mercury" is based on the height of a column of mercury at .Barry N. Taylor, ''Guide for the Use of the International System of Units (SI),'' 1995, NIST Special Publication 811, Appendix /ref> :1 inHg60 °F = In Imperial units: 1 inHg60 °F = 0.489 771 Pounds per square inch, psi, or 2.041 771 inHg60 °F = 1 psi. Applications Aircraft and automobiles Aircraft altimeters measure the relative pressure difference between the lower ambient pressure at altitude and a calibrated reading on the ground. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pascal (unit)
The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI), and is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is defined as one newton per square metre and is equivalent to 10 barye (Ba) in the CGS system. The unit of measurement called standard atmosphere (atm) is defined as 101,325 Pa. Common multiple units of the pascal are the hectopascal (1 hPa = 100 Pa), which is equal to one millibar, and the kilopascal (1 kPa = 1000 Pa), which is equal to one centibar. Meteorological observations typically report atmospheric pressure in hectopascals per the recommendation of the World Meteorological Organization, thus a standard atmosphere (atm) or typical sea-level air pressure is about 1013 hPa. Reports in the United States typically use inches of mercury or millibars (hectopascals). In Canada these reports are given in kilop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bar (unit)
The bar is a metric unit of pressure, but not part of the International System of Units (SI). It is defined as exactly equal to 100,000 Pa (100 kPa), or slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar). By the barometric formula, 1 bar is roughly the atmospheric pressure on Earth at an altitude of 111 metres at 15 °C. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, who was a founder of the modern practice of weather forecasting. The International System of Units, despite previously mentioning the bar, now omits any mention of it.. The bar has been legally recognised in countries of the European Union since 2004.British Standard BS 350:2004 ''Conversion Factors for Units''. The US National Institute of Standards and Technology (NIST) deprecates its use except for "limited use in meteorology" and lists it as one of several units that "must not be introduce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barometric Pressure
Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 760 mm Hg, 29.9212 inchesHg, or 14.696 psi.International Civil Aviation Organization. ''Manual of the ICAO Standard Atmosphere'', Doc 7488-CD, Third Edition, 1993. . The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth; that is, the Earth's atmospheric pressure at sea level is approximately 1 atm. In most circumstances, atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. As elevation increases, there is less overlying atmospheric mass, so atmospheric pressure decreases with increasing elevation. Because the atmosphere is thin relative to the Earth's radius—especially the dense atmospheric layer at low altitudes—the Earth's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Corps (United States Army)
) , colors = Orange and white , colors_label = Corps colors , march = , mascot = , equipment = , equipment_label = , battles = , anniversaries = 21 June 1860 , decorations = , battle_honours = , notable_commanders = BG Albert J. Myer BG Adolphus Greely , identification_symbol = , identification_symbol_label = Branch insignia , identification_symbol_2 = , identification_symbol_2_label = Regimental insignia , current_commander = , current_commander_label = , ceremonial_chief = Colonel Paul D. Howard , ceremonial_chief_label = Chief of Signal , command_sergeant_major = CSM Darien D. Lawshea , command_sergeant_major_label = Sergeant Major of the Regiment The United States Army Signal Corps (U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclogenesis
Tropical cyclogenesis is the development and strengthening of a tropical cyclone in the atmosphere. The mechanisms through which tropical cyclogenesis occurs are distinctly different from those through which temperate cyclogenesis occurs. Tropical cyclogenesis involves the development of a warm-core cyclone, due to significant convection in a favorable atmospheric environment. Tropical cyclogenesis requires six main factors: sufficiently warm sea surface temperatures (at least ), atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis force to develop a low-pressure center, a pre-existing low-level focus or disturbance, and low vertical wind shear. Tropical cyclones tend to develop during the summer, but have been noted in nearly every month in most basins. Climate cycles such as ENSO and the Madden–Julian oscillation modulate the timing and frequency of tropical cyclone development. There is a limit on tropical cyclo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinated Universal Time
Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about one second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). The coordination of time and frequency transmissions around the world began on 1 January 1960. UTC was first officially adopted as CCIR Recommendation 374, ''Standard-Frequency and Time-Signal Emissions'', in 1963, but the official abbreviation of UTC and the official English name of Coordinated Universal Time (along with the French equivalent) were not adopted until 1967. The system has been adjusted several times, including a brief period during which the time-coordination radio signals broadcast both UTC and "Stepped Atomic Time (SAT)" before a new UTC was adopted in 1970 and implemented in 1972. This change also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
