The elevated odds for a warm winter extend to the East Coast and Appalachian Mountains states. In the North, a wetter than average winter is favored from the Ohio Valley northwestward along the U.S.-Canada border.
How do changes in the equatorial Pacific Ocean impact places much farther away? The answer for the tropics, at least, lies in changes to the equator-wide atmospheric circulation called the Walker Circulation.
Guest blogger Marybeth Arcodia explains her latest research into how the Madden-Julian Oscillation and ENSO sometimes enhance each other's influence on U.S. precipitation and other times cancel each other out.
Arctic sea ice extent likely reached its annual minimum for 2020 on September 15. For the second time in the satellite record, sea ice extent dipped below 1.5 million square miles (4 million square kilometers).