A sting jet is a meteorological phenomenon which has been postulated to cause some of the most damaging winds in

extratropical cyclones Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of ...

, developing according to the Shapiro-Keyser model (though perhaps not exclusively) of oceanic cyclones.

Concept

Following reanalysis of the UK Great Storm of 1987, led by Professor

Keith Browning Keith Anthony Browning (born 31 July 1938) is a British meteorologist who worked at Imperial College London, the Met Office, and the University of Reading departments of meteorology. His work with Frank Ludlam on the supercell thunderstorm at ...

at the

University of Reading The University of Reading is a public university in Reading, Berkshire, England. It was founded in 1892 as University College, Reading, a University of Oxford extension college. The institution received the power to grant its own degrees in 192 ...

, researchers identified a mesoscale flow where the most damaging winds were shown to be emanating from the evaporating tip of the hooked cloud head on the southern flank of the cyclone. This cloud, hooked like a scorpion's tail, gives the wind region its name the "sting jet". It is thought that a zone of strong winds, originating from within the mid-tropospheric cloud head of an explosively deepening depression, are enhanced further as the " jet" descends, drying out and

evaporating Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. High concentration of the evaporating substance in the surrounding gas significantly slows down evaporation, such as when humidi ...

a clear path through snow and ice particles. The evaporative cooling leading to the air within the jet becoming denser, leading to an acceleration of the downward flow towards the tip of the cloud head when it begins to hook around the cyclone centre. Windspeeds in excess of 80 kn (150 km/h) can be associated with the sting jet. Sting jets are generally about 10 to 20 kilometres wide. A narrow area of land may be hit by very intense winds of or more, but 50 km away there may be the wind speeds associated with a normal storm, of about , making the damage from a sting jet very localised. Sting jets have been reproduced in high-resolution runs with the mesoscale version of the

Unified Model The Unified Model is a numerical weather prediction and climate modeling software suite originally developed by the United Kingdom Met Office, and now both used and further developed by many weather-forecasting agencies around the world. The Unif ...

of weather prediction. The sting jet is distinct from the usual strong-wind region associated with the warm conveyor belt and main

cold front A cold front is the leading edge of a cooler mass of air at ground level that replaces a warmer mass of air and lies within a pronounced surface trough of low pressure. It often forms behind an extratropical cyclone (to the west in the Northern ...

. There are indications that conditional symmetric

instability In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds. Not all systems that are not stable are unstable; systems can also be mar ...

also plays a role in its formation but the importance of these processes remains to be quantified. One North Atlantic storm, Cyclone Tilo (November 6–11, 2007) was analysed and found not to display a sting jet, despite generating strong surface winds and displaying a fractured cold front.

Globally

The sting jet mechanism has been considered less significant in

Pacific Northwest windstorm Pacific Northwest windstorms, sometimes colloquially known as Big Blows, are extratropical cyclones which form in the Pacific basin, and affect land areas in the Pacific Northwest of the United States and British Columbia, Canada. They form as cy ...

s which occur over the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

(which impact the

Northwestern United States The Northwestern United States, also known as the American Northwest or simply the Northwest, is an informal geographic region of the United States. The region consistently includes the states of Oregon, Washington, Idaho, Montana and Wyoming. ...

and

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

). Evidence of mesoscale high wind areas has not been noted in most large windstorms occurring there, along with cloud geometry associated with the phenomena being absent in satellite imagery of major Pacific Northwest storms. Although a case study of a sting jet in the region has been produced. High resolution computer models of the phenomena have also shown realistically strong winds without the need for sting jet dynamics.

List of sting jet cyclones

Sting jets can be spotted on satellite images as they develop, due to the end of the cold conveyor being marked by a scorpion-like hook-shaped cloud with a point at the end. About a dozen confirmed sting jets have been identified since the Great Storm of 1987 which led to their discovery. See the associated list.

External links

What is a sting jet? David M. Schultz and Keith A. Browning, Weather 72 (3) March 2017

The Sting Jet: Forecasting the damaging winds in European Cyclones, UK Met Office

The 1987 Great Storm - What is a Sting Jet?, UK Met Office

* [https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/qj.3267 Sting jets in extratropical cyclones: a review, Clark & Gray, Quarterly Journal of the Royal Meteorological Society, Volume 144, Issue 713 April 2018 Part B Pages 943-969]

References

{{Extratropical cyclones European windstorms Storm Wind Atmospheric dynamics

Concept

Globally

List of sting jet cyclones

External links

Further reading

References