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  • Location: Eastbourne, East Sussex (work in Mid Sussex)
  • Location: Eastbourne, East Sussex (work in Mid Sussex)

    Many people are frightened by the crackles and rumbles of thunder rather than the flash of lightning. However, thunder cannot hurt anybody, and the risk of being struck by lightning is far less than that of being killed in a car crash. Ninety per cent of lightning discharges go from cloud to cloud or between parts of the same cloud, never actually reaching the earth. Most of the discharges that do strike the ground cause little or no damage or harm. Lightning takes the shortest and quickest route to the ground, usually via a high object standing alone.

    In the USA:

    In the United States, an average of 300 people are injured and 80 people are killed each year by lightning. Although most lightning victims survive, people struck by lightning often report a variety of long-term, debilitating symptoms. Other associated dangers of thunderstorms include tornadoes, strong winds, hail, and flash flooding. Flash flooding is responsible for more fatalities—more than 140 annually—than any other thunderstorm-associated hazard.

    Dry thunderstorms that do not produce rain that reaches the ground are most prevalent in the western United States. Falling raindrops evaporate, but lightning can still reach the ground and can start wildfires.

    On average, the United States gets 100,000 thunderstorms each year

    Approximately 1,000 tornadoes develop from these storms

    Florida ranks first with a 100 thunderstorms days annually

    Large hail results in nearly $1 billion in damage to property and crops

    Approximately 10,000 forest fires are started each year by lightning

    Approximately $100 million in annual losses result from forest and building fires caused by lightning

    Straight-line winds exceeding 100 mph are responsible for most thunderstorm damage

    Some of the most severe occur when a single thunderstorm affects one location for an extended time.

    Thunderstorms typically produce heavy rain for a brief period, anywhere from 3 minutes to an hour.

    Warm, humid conditions are highly favorable for thunderstorm development.

    About 10 percent of thunderstorms are classified as severe—one that produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.

    Lightning’s unpredictability increases the risk to individuals and property.

    Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall.

    "Heat lightning" is actually lightning from a thunderstorm too far away for thunder to be heard. However, the storm may be moving in your direction!

    Most lightning deaths and injuries occur when people are caught outdoors in the summer months during the afternoon and evening.

    Your chances of being struck by lightning are estimated to be 1 in 600,000, but could be reduced even further by following safety precautions.

    Lightning strike victims carry no electrical charge and should be attended to immediately.

    And around the world:

    Number of thunderstorms occurring at any given moment: 2,000

    Number of lightning strikes every second: 100

    Number of lightning strikes a day: 8 million

    It has been estimated that are nearly 16 million thunderstorms annually all over the globe

    The average flash would light a 100 Watt light bulb for three months

    The average lightning stroke is six miles long

    A typical flash of folk lightning lasts for about 0.2 seconds

    The temperature of lightning's return stroke can reach 28,000 °C. The temperature on the surface of the sun is around 6,000 °C

    The Empire State Building in New York has been struck by lightning as much as 48 times in one day!

    The type of cloud which is usually responsible for thunderstorms is ‘cumulonimbus’ (a Latin word which translates to ‘rain heaps’). These types of clouds can span the entire troposphere and can be more than 12 miles high. During extreme storms, the updrafts can reach as high as 100 mph while the downdrafts can be even higher. Aircrafts totally avoid these types of clouds as the turbulence found inside them are usually on the extreme side.

    Across the globe, Kampala, Uganda holds the record of about 240 thunderstorm days annually

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    Posted
  • Location: Eastbourne, East Sussex (work in Mid Sussex)
  • Location: Eastbourne, East Sussex (work in Mid Sussex)

    And there's more!

    Thunder can only be heard about 12 miles away under good quiet outdoor conditions

    The average lightning bolt is 6-8 miles long and can easily travel 25 to 40 miles horizontally prior to turning downward toward the ground. In October 2001, the visual lightning detection system measured a single bolt that travelled from Waco to Fort Worth and then Dallas, Texas – a total distance of more than 110 miles

    85% of lightning victims are children and young men aged 10-35 engaged in outdoor recreation and work activities outside.

    70% of all lightning injuries and fatalities occur in the afternoon. 3 p.m. is the most dangerous time of day, it is five times more dangerous than 9 a.m.

    60% of victims are struck under blue skies after storms have passed

    New Mexico has the most lightning deaths per million people—1.88—based on statistics from 1959 to 1994

    The primary cause of death from lighting is cardiac arrest

    Golfer Lee Trevino has been struck by lightning twice

    Many survivors of lightning strikes report that immediately before being struck their hair was standing on end and they had a metallic taste in their mouth

    Long-term injuries from a lightning strike can include memory & attention loss, chronic numbness, muscle spasms & stiffness, depression, hearing loss, and sleep disturbance

    "Lightning Crawlers" or "Spider Lightning" can travel over 35 miles as it "crawls" across the bottoms or through squall line "frontal" clouds. This rare type of lightning is very beautiful as it zaps from "horizon-to-horizon". However it can turn deadly if it happens to strike the ground at the end of its super long path!

    How big around is a typical lightning bolt? Answer: About the size of a 10p piece. Lightning looks so much wider than it really is just because its light is so bright!

    Lightning Strikes create powerful radio waves in the frequency range of 3 KHz (audio, VLF) through 10 MHz (shortwave radio). The VLF (3000 Hz to 30000 Hz) "lightning signatures" can travel around the world, allowing monitoring of world-wide lightning. The shortwave "lightning signatures can travel half-way around the Earth (the night-time side of the Earth). The best region to listen for distant shortwave lightning signatures is from 2 MHz through 7 MHz. After 3 AM local time you can listen to 3 MHz and hear the beautiful dispersion-ringing of the static as it bounces back-and-forth between the earth and ionosphere. It can at times sound like hundreds of tiny bells ringing at once!

    NASA, the Space Shuttle and lightning

    The Kennedy Space Centre operates extensive lightning protection and detection systems in order to keep its employees, the 184-foot-high Space Shuttle, the launch pads and processing facilities from harm. While the protection system is exclusively on KSC property, the detection system incorporates equipment and personnel both at the space centre and Cape Canaveral Air Force Station (CCAFS), located just east of the Space Shuttle facility.

    Some of the facilities at the Kennedy Space Centre that incorporate extensive lightning-shielding devices include the service structures at Launch Pads 39A and 39B, the Vehicle Assembly Building (VAB) and the hangar-like Orbiter Processing Facility.

    An 80-foot fiberglass mast on top of the Fixed Service Structure at each pad is the most visible means of protecting the structure itself, the Shuttle while it is on the pad, and the enclosed launch equipment. The mast supports a 1-inch stainless steel cable that runs over its top. This cable stretches 1,000 feet in two directions to where each end is anchored and grounded. Its appearance is similar to that of a suspension bridge tower and its supporting cables. A 4-foot-high lightning rod on top of the mast is connected to the cable. The rod’s purpose is to prevent lightning current from passing directly through the Space Shuttle and the structures on the pad. Any strikes in this area would be conducted by the cable, called a Catenary Wire because of its shape, to the grounded anchor points.

    Other grounding systems in the Launch Complex 39 area include a network of buried, interconnected metal rods called the counterpoise that run under the launch pads and surrounding support structures. All structures in the area are grounded, including the VAB.

    Overhead gridwire systems protect hypergolic fuel and oxidizer storage areas at the pads. The huge 900,000-gallon liquid hydrogen and oxygen tanks also at each pad are constructed of metal and do not need overhead protection, since they provide their own grounds.

    Away from the pad, the Shuttle is well protected from both inclement weather and lightning when it is in the VAB. This 525-foot-high structure, one of the largest in the world, has its own system of eleven 25-foot-high lightning conductor towers on its roof. When lightning hits the system, wires conduct the charge to the towers, which then direct the current down the VAB’s sides and into its foundation pilings that are driven into bedrock.

    The Kennedy Space Centre has pioneered a two-phase lightning warning policy. In Phase I, an Advisory is issued that lightning is forecast within five miles of the designated site within 30 minutes of the effective time of the Advisory. The 30-minute warning gives personnel in unprotected areas time to get to protective shelter and gives personnel working on lightning sensitive tasks time to secure operations in a safe and orderly manner. A Phase II Warning will be issued when lightning is imminent or occurring within five miles of the designated site. All lightning-sensitive operations are terminated until the Phase II Warning is lifted. This two-phase policy provides adequate lead time for sensitive operations without shutting down less sensitive operations until the hazard becomes immediate.

    The Lightning Policy is defined by the KSC Lightning Safety Assessment Committee. This group is also responsible for seeing that all structures at KSC, as well as the Space Shuttle, are adequately protected. Structures that particularly need protection against lightning include those that contain ignitable, explosive or flammable materials, and personnel.

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  • Location: Eastbourne, East Sussex (work in Mid Sussex)
  • Location: Eastbourne, East Sussex (work in Mid Sussex)

    Tornado facts and figures

    The conditions that lead to the formation of tornadoes are most often met in the Central and Southern U.S., where warm, humid air from the Gulf of Mexico collides with cool, dry air from the Rockies and Canada. This area, dubbed "tornado alley," extends roughly from the Rocky Mountains to the Appalachians, and from Iowa and Nebraska to the Gulf of Mexico. Tornadoes can also occur elsewhere, though, including all U.S. states, Europe, Asia, and Australia.

    The USA

    The average number of tornadoes per year in the United States (1950–2004) is 910

    The central states of the US are highly prone to tornadoes, which are typically more violent and extensive than those in Europe. On April 3-4 1974 there were 148 tornadoes, causing 315 deaths, in 13 states from Georgia to the Canadian border.

    The Top 5 states with highest incidence of tornadoes (average per year, 1950–2004) are: Texas (134), Oklahoma (58), Kansas (56), Florida (51), Nebraska (43)

    US States with lowest incidence of tornadoes (total number, 1950–2004) are Alaska (2), Rhode Island (9), Hawaii (31), Vermont (37), Oregon (87)

    Most tornadoes in one month in the USA: 543 (May 2003)

    Most tornado deaths in one year in the USA: 519 (1953)

    Fewest tornado deaths in one year in the USA: 15 (1986)

    What is believed to be the most violent tornado in US history struck on 18 March 1925, killing 689 people, injuring 1980 others, destroying 4 towns, severely damaging 6 others and leaving 11,000 homeless across Missouri, Indiana and Illinois.

    The UK

    The UK experiences more tornadoes than any other country in the world in proportion to its land area. On November 23 1981, 105 tornadoes struck in five-and-a-half hours across England.

    One of the most powerful tornadoes ever to strike Britain hit London with winds estimated at between 213 mph and 240 mph on October 23 1091. St Mary le Bow church was destroyed and four 8 metre rafters were driven into the ground with such force that only a metre and a bit protruded.

    In the most severe tornadoes wind speeds can approach 300 mph.

    On average, 33 tornadoes are logged each year in the UK, but many more are presumed to go unreported because they strike open land.

    Some tornadoes form at sea as strong waterspouts which produce a tornado as they hit the coast. On January 7 1998 in Selsey, West Sussex, a waterspout carved a trail of damage a kilometre wide through the town, damaging hundreds of buildings in less than 10 minutes.

    The Birmingham tornado of July 2005 damaged 1,000 homes, 90 businesses and injured 22 people in four minutes. A tornado of this intensity is expected of an urban area in the UK every five to 10 years.

    Dr Terence Meaden, the founder of TORRO, said that the areas of the UK most prone to tornadoes are the South and East of England. "The highest might well be the South coast, East of the Isle of Wight" ;)

    The rest of the World

    On average, 330 tornadoes are reported each year in Europe. The estimated "true" number of tornadoes is around 700 per year. In addition to tornadoes reported on land, this figure includes twisters observed on water, often referred to as waterspouts.

    Until recently, many climatologists quoted a figure of around 100 tornadoes per year for Europe. This was based on an estimate made by the German scientist Alfred Wegener in 1917. It stuck for over eight decades.

    The deadliest tornado in history struck Bangladesh on April 26 1989, killing 1,300 people.

    The Netherlands is in second place in the European twister league, with an estimated 35 twisters each year over its comparatively small land area

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