ESS5
Prof. Jin-Yi Yu
Positive NAO Index
Stronger subtropical high and a deeper than normal Icelandic low.
More and stronger winter storms crossing the Atlantic Ocean on a more northerly track.
Warm and wet winters in Europe and in cold and dry winters in northern Canada and Greenland
The eastern US experiences mild and wet winter conditions
Negative NAO Index
Weak subtropical high and weak Icelandic low.
Fewer and weaker winter storms crossing on a more west-east zonal pathway.
Moist air into the Mediterranean and cold air to northern Europe
US east coast experiences more cold air outbreaks and hence snowy weather conditions.
Greenland, however, will have milder winter temperatures
Positive Phase
Negative Phase