User:Lacunae/3

Sting jet
'''it's possible that a "sting jet" could develop on the southwest side of the low pressure area. Such features, which involve cold, dry air descending rapidly from high in the atmosphere, can lead to areas of damaging winds topping 100 miles per hour in some cases, and are occasionally seen in rapidly intensifying storms in and around the UK.'''-http://mashable.com/2015/01/13/major-uk-storm-rachel/

A sting jet is a transient mesoscale meteorological phenomenon found in some extratropical cyclones lasting for only a few hours  which are believed to be the cause of some of the most damaging winds in European windstorms. Satellite Imagery of Pacific Northwest windstorms has shown little evidence of circulations that occur in the sting jet model however, Sting Jet are possible in these storms but so far there is little evidence that they are important in these storms.

Following reanalysis of the Great Storm of 1987, led by Professor Keith Browning at the University of Reading, 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 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.

It has since been reproduced in high-resolution runs with the mesoscale version of the Unified Model. The Sting jet is distinct from the usual strong-wind region associated with the warm conveyor belt and main cold front. There are indications that conditional symmetric instability also plays a role in its formation but the importance of these processes remains to be quantified.

Sting jet

Shapiro Keyser Model
A second competing theory for extratropical cyclone development over the oceans is the Shapiro-Keyser model, developed in 1990. Its main differences with the Norwegian Cyclone Model are the fracture of the cold front, treating warm-type occlusions and warm fronts as the same, and allowing the cold front to progress through the warm sector perpendicular to the warm front. This model was based on oceanic cyclones and their frontal structure, as seen in surface observations and in previous projects which used aircraft to determine the vertical structure of fronts across the northwest Atlantic.

'''Analysis of the "Great Storm of 1987" (hereafter the Great Storm) byBrowning and Field(2004)identified a mesoscale region of high winds that was not associated with any of the previouslydocumented jets and has become known as a sting jet. The term originated from the descriptionof "the dangerous sting in the tail" of the 1992 New Years Day storm (Grønås,1995).'''
 * Grønås (1995)

links
Laura Baker | Oscar Martinez-Alvarado | Suzanne Gray | Peter Clark (Met Office)
 * Idealised simulations of sting jet cyclones  Laura Baker http://www.met.reading.ac.uk/~rx738026/reports/rmets09_poster_A4.pdf
 * An idealised simulation of a sting jet cyclone Baker. Gray, Clark http://www.met.reading.ac.uk/~rx738026/reports/Laura_Baker_EGU_poster.pdf
 * Sting-jet extratropical cyclones in ERA-Interim Oscar Martinez Alvarado, Suzanne Gray http://www.pandowae.de/files/TH-ERM/Talks/Posters/THORPEX_poster_OM-A.pdf
 * http://www.met.reading.ac.uk/~rx738026/reports/NCAS_2008_poster_A4.pdf Sting jets in severe Northern European wind storms
 * http://www.met.rdg.ac.uk/mwp/meso/Research/sting_jets.html Sting jets in severe Northern European windstorms Mesoscale group Reading Uni
 * http://www.met.reading.ac.uk/~sws07om/publications/sting_jets_EMS08.ppt Conditional Symmetric Instability and the Development of Sting Jets Martinez-Alvarado 2008 (.ppt)
 * http://meetingorganizer.copernicus.org/EGU2010/EGU2010-4958.pdf abstract
 * http://www.docstoc.com/docs/75134567/Sting-Jets-in-Severe-Northern-European-Wind-Storms
 * http://www.met.reading.ac.uk/~rx738026/stingjet/


 * Browning (2004)
 * Clark wt al. (2005)
 * Baker (2009)
 * Parton et al. (2009)
 * Martinez-Alvarado et al. (2010)
 * Mass & Dotson 2010
 * Gray et al. (2011)
 * Knox et al. (2011)
 * Geographical Association

Further things

 * | NOAA CONDITIONAL SYMMETRIC INSTABILITY (CSI) HOMEPAGE