Sting Jets in Severe Northern European windstorms

Dr Suzanne Gray
Prof. Peter Clark
Dr Oscar Martínez-Alvarado
Dr Laura Baker
Dr Neil Hart

Background

Sting jets occur in rapidly deepening extratropical cyclones leading to localised regions of extremely damaging winds. Although their existence has only recently been recognised, it has been shown that the winds that constitute the sting jet descend from the region near the bent-back warm front, which marks the 'tail' of the characteristic 'hook' of the cloud head, hence their name.

Despite their potential significance as an output of weather prediction, current numerical weather prediction (NWP) models are unable to explicitly resolve this phenomenon apparently due to a poor vertical resolution. This fact makes it desirable to develop diagnostics for the prediction of sting jets. Nevertheless, the number of case studies so far is limited and there are still various unanswered questions concerning the physical processes involved in the development of sting jets. For example, evaporative cooling and slantwise convection are two processes that are known to have an important role in the occurrence of sting jets. However, it remains to be quantitatively determined the relative importance of these processes.

Projects

Sting Jets were first investigated by Prof. Keith Browning, and first studied using model simulations by Peter Clark.

The first formally funded project, "Sting Jets in Severe Northern European windstorms" was funded by NERC and led by Sue Gray, aided and abetted by Peter Clark. Within this project, Oscar Martínez-Alvarado studied further cases and developed a diagnostic to identify potential sting-jet storms using data from models run at too low resolution to explicitly form a sting jet.

Laura Baker achieved her PhD developing an idealised configuration of the UM developing cyclones with explicit sting jets, and went on to study sting-jet precursors.

The current project in this area is called "Sting jet windstorms in current and future climates", funded by AXA, again led by Sue Gray, aided and abetted by Peter Clark. Neil Hart is studying the predictability of Sting Jets using ensemble techniques.