Hurricane

The North Atlantic Oscillation (NAO) describes the fluctuations in the difference of atmospheric pressure at sea level between (1) Greenland and Iceland that generally experience lower air pressure than surrounding regions, called the sub-polar low, or sometimes the Icelandic Low, and (2) farther to the south, air pressure over the central North Atlantic Ocean is generally higher than surrounding regions. This atmospheric feature is called the subtropical high, or the Azores High. The increased difference in pressure between the two regions results in a stronger Atlantic jet stream and a northward shift of the hurricane and storm tracks. During a negative phase of NAO, eastern North America and the Caribbean experience lower air pressure which is associated with stronger cold-air outbreaks and an increase hurricane season.