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