Polar lows are similar in behavior and size to tropical cyclones, although generally much shorter lived.
Polar Lows are typically several hundred kilometres in diameter, generally have strong winds (although generally not at hurricane intensity) and last one to two days on average. Unlike most typical cyclones they develop extremely rapidly reaching peak intensity within 24 hours. They generally form under cold upper-level lows when cold arctic air flows over a warm body of water.
On satellite imagery Polar Lows appear very similar to hurricanes with an eye and convective bands wrapping the storm in the counter-clockwise fashion. Research aircraft data suggests that these 'Arctic Hurricanes' may be warm-cored systems. Polar Lows are currently difficult to predict due to scarcity of data. Most predictions in this area are more subjective than the prediction of tropical cyclones.