The National and Oceanic Atmospheric Administration (NOAA) recently updated its U.S. Winter Outlook for December through February, which continues to call for warmer-than-normal conditions in the West and Alaska.
For precipitation, NOAA's outlook calls for drier-than-average conditions in the Pacific Northwest and Ohio Valley and wetter-than-average conditions over parts of the South.
Currently, NOAA is monitoring a weak El Nino in the tropical Pacific, which is expected to continue into early 2005. However, NOAA scientists predict this El Nino will remain much weaker than the 1997-1998 El Nino event.
"El Nino wintertime impacts over the United States vary considerably depending on the character of the warming in the tropical Pacific," said Vernon Kousky, NOAA's lead El Nino/Southern Oscillation forecaster. "While we are carefully monitoring this current El Nino episode."
NOAA scientists say the leading climate patterns expected to impact this winter's weather are long-term climate trends and features such as the El Nino/Southern Oscillation (ENSO) and the Pacific/North American pattern (PNA), which influence the jet stream and the track storms take across the eastern Pacific and North America.