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Teton–Yellowstone Tornado
The Teton–Yellowstone tornado was a rare high-altitude tornado which occurred on July 21, 1987, in the U.S. state of Wyoming. Rated at F4 on the Fujita scale, it remains the strongest tornado ever recorded in the state and the only recorded F4/EF4 tornado in Wyoming history. The tornado cut through a -long and -wide swath of the Teton Wilderness and Yellowstone National Park, crossing the Continental Divide. Damage occurred at elevations ranging from , making it the highest-altitude violent tornado recorded in the United States. At the time, it was the highest-elevation tornado known, since surpassed by several others, including a 2004 tornado above 12,000 feet in California's Sequoia National Park. While no human fatalities or injuries occurred, an estimated one million trees were felled by the tornado. The tornado damage was originally thought to be the result of strong thunderstorm straight-line winds until the area was surveyed by University of Chicago severe weather mete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Time Zone
The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC) when standard time ( UTC−07:00) is in effect, and by subtracting six hours during daylight saving time ( UTC−06:00). The clock time in this zone is based on the mean solar time at the 105th meridian west of the Greenwich Observatory. In the United States, the exact specification for the location of time zones and the dividing lines between zones is set forth in the Code of Federal Regulations at 49 CFR 71. In the United States and Canada, this time zone is generically called Mountain Time (MT). Specifically, it is Mountain Standard Time (MST) when observing standard time, and Mountain Daylight Time (MDT) when observing daylight saving time. The term refers to the Rocky Mountains, which range from British Columbia to New Mexico. In Mexico, this time zone is known as the or ("Pacific Zone"). In the US and Canada, the Mountain Time Zone is to the east of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picea Engelmannii
''Picea engelmannii'', with the common names Engelmann spruce, white spruce, mountain spruce, and silver spruce, is a species of spruce native to western North America. It is mostly a high-altitude mountain tree but also appears in watered canyons. Description ''Picea engelmannii'' is a medium-sized to large evergreen tree growing to tall, exceptionally to tall, and with a trunk diameter of up to . The reddish bark is thin and scaly, flaking off in small circular plates across. The crown is narrow conic in young trees, becoming cylindric in older trees. The shoots are buff-brown to orange-brown, usually densely pubescent, and with prominent pulvini. The leaves are needle-like, long, flexible, rhombic in cross-section, glaucous blue-green above with several thin lines of stomata, and blue-white below with two broad bands of stomata. The needles have a pungent odour when crushed. Purple cones of about 1 cm appear in spring, releasing yellow pollen when windy. The cones are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windthrow
In forestry, windthrow refers to trees uprooted by wind. Breakage of the tree bole (trunk) instead of uprooting is called windsnap. Blowdown refers to both windthrow and windsnap. Causes Windthrow is common in all forested parts of the world that experience storms or high wind speeds. The risk of windthrow to a tree is related to the tree's size (height and diameter), the 'sail area' presented by its crown, the anchorage provided by its roots, its exposure to the wind, and the local wind climate. A common way of quantifying the risk of windthrow to a forest area is to model the probability or 'return time' of a wind speed that would damage those trees at that location. Another potential method is the detection of scattered windthrow based on satellite images. Tree senescence can also be a factor, where multiple factors contributing to the declining health of a tree reduce its anchorage and therefore increase its susceptibility to windthrow. The resulting damage can be a si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellowstone River
The Yellowstone River is a tributary of the Missouri River, approximately long, in the Western United States. Considered the principal tributary of upper Missouri, via its own tributaries it drains an area with headwaters across the mountains and Great Plains, high plains of southern Montana and northern Wyoming, and stretching east from the Rocky Mountains in the vicinity of Yellowstone National Park. It flows northeast to its confluence with the Missouri River on the North Dakota side of the border, about 25 miles west of present-day Williston, North Dakota, Williston. Yellowstone watershed The Yellowstone River watershed is a river basin spanning across Montana, with minor extensions into Wyoming and North Dakota, toward headwaters and terminus, respectively. The Yellowstone Basin watershed contains a system of rivers, including the Yellowstone River, and four tributary basins: the Clarks Fork Yellowstone, Wind River (Wyoming), Wind River and Bighorn River, Tongue River (Mon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirque
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform arising from fluvial erosion. The concave shape of a glacial cirque is open on the downhill side, while the cupped section is generally steep. Cliff-like slopes, down which ice and glaciated debris combine and converge, form the three or more higher sides. The floor of the cirque ends up bowl-shaped, as it is the complex convergence zone of combining ice flows from multiple directions and their accompanying rock burdens. Hence, it experiences somewhat greater erosion forces and is most often overdeepened below the level of the cirque's low-side outlet (stage) and its down-slope (backstage) valley. If the cirque is subject to seasonal melting, the floor of the cirque most often forms a tarn (small lake) behind a dam, which marks the down ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacific Creek (Teton County, Wyoming)
Pacific Creek begins in the Teton Wilderness of Bridger-Teton National Forest in the U.S. state of Wyoming. The creek originates from North Two Ocean Creek, which splits into Pacific and Atlantic Creeks at Two Ocean Pass along the Continental Divide. Pacific Creek travels southwest into Grand Teton National Park and receives outflow from Two Ocean and Emma Matilda Lakes just before it empties into the Snake River immediately northwest of Moran, Wyoming Moran (also Moran Junction) is an unincorporated village in south central Teton County, Wyoming, United States: as the community has had two different names, the Board on Geographic Names officially ruled in favor of "Moran" in 1970. It lies in .... Pacific Creek has a watershed which covers . References Rivers of Wyoming Rivers of Teton County, Wyoming River bifurcations Wild and Scenic Rivers of the United States {{Wyoming-river-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Funnel Cloud
A funnel cloud is a funnel-shaped cloud of condensed water droplets, associated with a rotating column of wind and extending from the base of a cloud (usually a cumulonimbus or towering cumulus cloud) but not reaching the ground or a water surface. A funnel cloud is usually visible as a cone-shaped or needle like protuberance from the main cloud base. Funnel clouds form most frequently in association with supercell thunderstorms, and are often, but not always, a visual precursor to tornadoes. Funnel clouds are visual phenomena, these are not the vortex of wind itself. "Classic" funnel clouds If a funnel cloud touches the surface the feature is considered a tornado, although ground level circulations begin before the visible condensation cloud appears. Most tornadoes begin as funnel clouds, but some funnel clouds do not make surface contact and these cannot be counted as tornadoes from the perspective of a naked eye observer, even as tornadic circulations of some intensity alm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud Base
A cloud base (or the base of the cloud) is the lowest altitude of the visible portion of a cloud. It is traditionally expressed either in metres or feet above mean sea level or above a planetary surface, or as the pressure level corresponding to this altitude in hectopascals (hPa, equivalent to the millibar). Measurement The height of the cloud base can be measured using a ceilometer. This device reflects a beam of light off the cloud base and then calculates its distance using either triangulation or travel time. Alternatively, the cloud base can be estimated from surface measurements of air temperature and humidity by calculating the lifted condensation level. One method for doing this, used by the U.S. Federal Aviation Administration and often named after Tom Bradbury, is as follows: #Find the difference between the surface temperature and the dew point. This value is known as the "spread". #Divide the spread by 4.4 (if temperatures are in °F) or 2.5 (if temperatures are i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hailstones
Hail is a form of solid precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fall in cold weather, while hail growth is greatly inhibited during low surface temperatures. Unlike other forms of water ice precipitation, such as graupel (which is made of rime ice), ice pellets (which are smaller and translucent), and snow (which consists of tiny, delicately crystalline flakes or needles), hailstones usually measure between and in diameter. The METAR reporting code for hail or greater is GR, while smaller hailstones and graupel are coded GS. Hail is possible within most thunderstorms (as it is produced by cumulonimbus), as well as within of the parent storm. Hail formation requires environments of strong, upward motion of air within the parent thunderstorm (similar to tornadoes) and lowered heights of the freezin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridger–Teton National Forest
Bridger–Teton National Forest is located in western Wyoming, United States. The forest consists of , making it the third largest National Forest outside Alaska. The forest stretches from Yellowstone National Park, along the eastern boundary of Grand Teton National Park and from there rides along the western slope of the Continental Divide to the southern end of the Wind River Range. The forest also extends southward encompassing the Salt River Range and Wyoming Range mountains near the Idaho border. Geography Located within the forest are the Gros Ventre, Bridger and Teton Wildernesses, totaling . Other points of interest contained in the forest include Gannett Peak at , the tallest mountain in Wyoming, and the Gros Ventre landslide, which is one of the largest readily visible landslides on earth. All of the forest is in turn a part of the Greater Yellowstone Ecosystem. While Gannett Peak is the highest summit in the forest, another 40 named mountains rise above . The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1974 Super Outbreak
The 1974 Super Outbreak was the second-largest tornado outbreak on record for a single 24-hour period, just behind the 2011 Super Outbreak. It was also the most violent tornado outbreak ever recorded, with 30 F4/F5 tornadoes confirmed. From April 3 to 4, 1974, there were 148 tornadoes confirmed in 13 U.S. states and the Canadian province of Ontario. In the United States, tornadoes struck Illinois, Indiana, Michigan, Ohio, Kentucky, Tennessee, Alabama, Mississippi, Georgia, North Carolina, Virginia, West Virginia, and New York. The outbreak caused roughly $843 million USD (~equivalent to $4.58 billion in 2019) in damage, with more than $600 million (~equivalent to $3.3 billion in 2019) occurring in the United States. The outbreak extensively damaged approximately along a total combined path length of . At one point, as many as 15 separate tornadoes were on the ground simultaneously. The 1974 Super Outbreak was the first tornado outbreak in recorded history to produce more than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Tornadoes In The 1974 Super Outbreak
This is the list of tornadoes confirmed that occurred during the record-breaking 1974 Super Outbreak tornado event that occurred on April 3–4, 1974 across the eastern half of the United States and in Ontario, Canada. __TOC__ Tornadoes confirmed *Note: Some tornadoes are not yet included in this table. April 3 event *Note: Path lengths and widths, tornado start times, injuries, and deaths sometimes vary from source to source; information listed here may conflict other sources. April 4 event *Note: Path lengths and widths, tornado start times, injuries, and deaths sometimes vary from source to source; information listed here may conflict other sources. See also *1974 Super Outbreak *2011 Super Outbreak *List of tornadoes in the 2011 Super Outbreak *Tornadoes *List of F5 and EF5 tornadoes This is a list of tornadoes which have been officially or unofficially labeled as F5, EF5, T10-T11, IF5, or an equivalent rating, the highest possible ratings on the various tornado ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
