Map of the 1991 West Virginia Derecho (courtesy of NOAA)
The 1991 West Virginia derecho was a serial derecho (storm) that started in Arkansas in the early morning hours of April 9, 1991, and made its way northeast, finally dying out over Pennsylvania late that evening.
Two people were killed and 145 were injured in the event, mainly from falling trees, flying debris, and mobile homes and trailers being overturned.[2] Western and central West Virginia were affected by hail and several roads were blocked.[3]
In West Virginia alone, there were 8,000 insurance damage claims for homes and businesses. More than 200,000 people lost power in the derecho. Many people experienced flickering lights and power surges. This derecho was the worst severe weather event for West Virginia since the 1974 Super Outbreak.[4]
What is a Derecho?Edit
There are several criteria for a mesoscale convective system (MCS) to be considered a derecho. The system needs to have sustained winds of 58 mph, and stretch along a boundary at least 250 miles long. There must also be isolated wind gusts of 75 mph or greater.
Formation of a DerechoEdit
There needs to be sufficient convective available potential energy (CAPE) in the atmosphere for several thunderstorm cells to form.
There needs to be sufficient inflow of air in the lower atmosphere, with strong upper level divergence in the upper atmosphere.
There needs to be an elevated mixed layer leading to a rapid decrease in temperature with height.
There needs to be high values of vertical wind shear (45 mph or greater) in the lowest 5 kilometers of the atmosphere.
This is a rather simplified list of conditions needed to form a derecho. However, when all of these conditions occur simultaneously in the atmosphere, a derecho storm system has the potential to form.
Storm Prediction Center's "About Derechos" summary of the West Virginia Derecho of April 1991
October 21, 2023
1991, west, virginia, derecho, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jst. 34 48 N 92 12 W 34 8 N 92 2 W 34 8 92 2 This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources 1991 West Virginia derecho news newspapers books scholar JSTOR May 2013 Learn how and when to remove this template message Map of the 1991 West Virginia Derecho courtesy of NOAA The 1991 West Virginia derecho was a serial derecho storm that started in Arkansas in the early morning hours of April 9 1991 and made its way northeast finally dying out over Pennsylvania late that evening It was the worst severe weather event for West Virginia since the 1974 Super Outbreak 1 Contents 1 Description 2 Damage claims 3 What is a Derecho 4 Formation of a Derecho 5 See also 6 References 7 External linksDescription EditTwo people were killed and 145 were injured in the event mainly from falling trees flying debris and mobile homes and trailers being overturned 2 Western and central West Virginia were affected by hail and several roads were blocked 3 Most of the destructive damage occurred in Tennessee Kentucky West Virginia western Maryland and Western Pennsylvania The fatalities associated with this storm occurred in Charleston West Virginia and Huntington West Virginia as a result of the high winds 3 Damage claims EditIn West Virginia alone there were 8 000 insurance damage claims for homes and businesses More than 200 000 people lost power in the derecho Many people experienced flickering lights and power surges This derecho was the worst severe weather event for West Virginia since the 1974 Super Outbreak 4 What is a Derecho EditThere are several criteria for a mesoscale convective system MCS to be considered a derecho The system needs to have sustained winds of 58 mph and stretch along a boundary at least 250 miles long There must also be isolated wind gusts of 75 mph or greater Formation of a Derecho EditThere needs to be sufficient convective available potential energy CAPE in the atmosphere for several thunderstorm cells to form There needs to be sufficient inflow of air in the lower atmosphere with strong upper level divergence in the upper atmosphere There needs to be an elevated mixed layer leading to a rapid decrease in temperature with height There needs to be high values of vertical wind shear 45 mph or greater in the lowest 5 kilometers of the atmosphere The system usually has a bow echo type of shape This is a rather simplified list of conditions needed to form a derecho However when all of these conditions occur simultaneously in the atmosphere a derecho storm system has the potential to form See also EditList of derecho eventsReferences Edit The West Virginia Derecho of 1991 The West Virginia Derecho of 1991 www spc noaa gov Retrieved 2017 05 03 a b High winds kill 2 in west virginia Chicago Tribune April 10 1991 The West Virginia Derecho of 1991External links EditStorm Prediction Center s About Derechos summary of the West Virginia Derecho of April 1991 Retrieved from https en wikipedia org w index php title 1991 West Virginia derecho amp oldid 1173839084, wikipedia, wiki, book, books, library,
