Helm Wind
Encyclopedia
The Helm Wind is a named wind
in Cumbria
, England
, a strong north-easterly wind which blows down the south-west slope of the Cross Fell
escarpment. It is the only named wind in the British Isles
, although many other mountain regions in Britain exhibit the same phenomenon when the weather conditions are favourable. It may take its name from the helmet
or cap
of cloud
which forms above Cross Fell, known as the Helm Bar, since a line of clouds
over the fells can predict and accompany a Helm. Research into the helm wind was carried out by Gordon Manley
in the 1930s. He interpreted the phenomenon in hydrodynamic terms as a "standing wave
" and "rotor", a model confirmed in 1939 by glider flights.
at the head of the Eden Valley has its own Helm Wind, which sweeps over Mallerstang
Edge, particularly affecting the central part of the dale. This can be similarly fierce and can blow for two days or more, sometimes sounding like an express train. As with the wind at Cross Fell, its arrival is accompanied by the formation of a dense cap of cloud (a "Helm Bar") which, in this case, forms along the high ground on the eastern side of the dale.
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
in Cumbria
Cumbria
Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
, a strong north-easterly wind which blows down the south-west slope of the Cross Fell
Cross Fell
Cross Fell is the highest point in the Pennine Hills of northern England and the highest point in England outside of the Lake District.The summit, at , is a stony plateau, part of a long ridge running North West to South East, which also incorporates Little Dun Fell at and Great Dun Fell at...
escarpment. It is the only named wind in the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
, although many other mountain regions in Britain exhibit the same phenomenon when the weather conditions are favourable. It may take its name from the helmet
Helmet
A helmet is a form of protective gear worn on the head to protect it from injuries.Ceremonial or symbolic helmets without protective function are sometimes used. The oldest known use of helmets was by Assyrian soldiers in 900BC, who wore thick leather or bronze helmets to protect the head from...
or cap
Cap
A cap is a form of headgear. Caps have crowns that fit very close to the head and have no brim or only a visor. They are typically designed for warmth and, when including a visor, blocking sunlight from the eyes...
of cloud
Pileus (meteorology)
A pileus , also called scarf cloud or cap cloud, is a small, horizontal cloud that can appear above a cumulus or cumulonimbus cloud, giving the parent cloud a characteristic "hoodlike" appearance. Pilei tend to change shape rapidly. They are formed by strong updrafts acting upon moist air at lower...
which forms above Cross Fell, known as the Helm Bar, since a line of clouds
Lenticular cloud
Lenticular clouds are stationary lens-shaped clouds that form at high altitudes, normally aligned perpendicular to the wind direction. Lenticular clouds can be separated into altocumulus standing lenticularis , stratocumulus standing lenticular , and cirrocumulus standing lenticular...
over the fells can predict and accompany a Helm. Research into the helm wind was carried out by Gordon Manley
Gordon Manley
Gordon Valentine Manley, FRGS was an English climatologist who assembled the Central England temperature series of monthly mean temperatures stretching back to 1659. This is the longest standardised instrumental record available for anywhere in the world...
in the 1930s. He interpreted the phenomenon in hydrodynamic terms as a "standing wave
Standing wave
In physics, a standing wave – also known as a stationary wave – is a wave that remains in a constant position.This phenomenon can occur because the medium is moving in the opposite direction to the wave, or it can arise in a stationary medium as a result of interference between two waves traveling...
" and "rotor", a model confirmed in 1939 by glider flights.
The Helm Wind in Mallerstang
The daleDale (origin)
A dale is an open valley. The name is used when describing the physical geography of an area. It is used most frequently in the Lowlands of Scotland and in the North of England, where the term "fell" commonly refers to the mountains or hills that flank the dale.The word dale comes from the Old...
at the head of the Eden Valley has its own Helm Wind, which sweeps over Mallerstang
Mallerstang
Mallerstang is a civil parish in the extreme east of Cumbria, and, geographically, a dale at the head of the upper Eden Valley. Originally part of Westmorland, it lies about south of the nearest town, Kirkby Stephen...
Edge, particularly affecting the central part of the dale. This can be similarly fierce and can blow for two days or more, sometimes sounding like an express train. As with the wind at Cross Fell, its arrival is accompanied by the formation of a dense cap of cloud (a "Helm Bar") which, in this case, forms along the high ground on the eastern side of the dale.
External links
- Helm-Wind article from Penny MagazinePenny MagazineThe Penny Magazine, published every Saturday from 31 March 1832 to 31 October 1845, was an illustrated British magazine aimed at the working class. Charles Knight created it for the Society for the Diffusion of Useful Knowledge in response to Chambers's Edinburgh Journal, which started two months...
- Images Of Cumbria - The Helm Wind (no actual images)
- A Helm Bar over Mallerstang Edge
- New Scientist Premium- Histories: When the helm wind blows - Histories
- Example of a Helm Bar taken from near Appleby in Westmorland on April 3rd 2007
- Helm Wind article on a website that specialises in "wind of the world".
