Polar low

A polar low is a small sized and short-lived atmospheric low pressure system that is found over the ocean areas pole ward of the main polar front in both the Northern and Southern Hemispheres. The systems usually have a horizontal length scale of less than 1,000 km and live for less than a couple of days. They are part of the larger class of mesoscale weather systems. Polar lows can be difficult to detect using standard weather reports and are a problem to high-latitude operations, such as shipping and gas and oil platforms.

Polar lows have been also known as by using many other terms, such as comma cloud, mesocyclone, polar mesoscale vortex, Arctic hurricane, Arctic low, and cold air depression. Today the term is usually set aside for the more-energetic systems that have near-surface winds of at least gale force (17 m/s).

Other websites
 European Polar Lows Working Group 
 NSIDC 
 Polar Low Forecasting by MetEd

Further reading
Rasmussen,E.A. and Turner,J.(2003). Polar Lows: Mesoscale Weather Systems in the Polar Regions, Cambridge University Press, Cambridge, pp 612.

Category:Meteorology