The forecast likelihood for weak or moderate La Niña conditions to persist through the Northern Hemisphere winter increased in a monthly U.S. government weather forecast update.
The Climate Prediction Center (CPC), an agency of the National Weather Service, pegged the chance of La Nina persisting through the winter at about 80 percent, up from 65 to 75 percent in the November forecast.
CPC expects conditions will transition to ENSO-neutral most likely during the mid-to-late spring.
The phenomenon, characterized by unusually cold ocean temperatures in the equatorial Pacific Ocean, tends to deliver wetter than normal weather in the western Pacific and drier than normal conditions in Argentina.
It also favours above-average temperatures and below-median precipitation across the southern tier of the United States and can deliver colder, snowy conditions to the Northern U.S. and parts of Canada.
So far though, Western Canada has had a mild December.