News and Events
Climate Outlook for Fall 2003/Winter 2004
4 November 2003
Seasonal forecasting is a type of gambling. Various factors change the odds for a winter that is, say, warmer and drier than normal. El Niņo, a rearrangement of warm water and rainfall in the tropical Pacific, is the most important such factor: it changes the odds for different types of winter and spring weather here in the Northwest.
Tropical Pacific now: After a medium-sized El Niño dissipated this spring, it looked as if it would be followed by another La Niña. Now those early indications have proven false and it looks unlikely that either El Niño or La Niña will be around in the next year. (See the Climate Prediction Center's discussion.)
What will it mean for the Northwest in coming months? With little forecasting help from the tropical Pacific, the odds for precipitation are roughly normal for most seasons in the next year but the odds for temperature are tilted somewhat to above-average for the foreseeable future, a reflection largely of recent trends toward warmer weather (e.g., 10 of the last 12 months have been at least 1F warmer than "normal" in Washington state).
How did you do last year? Because an El Niño event was developing in the tropics, we said there was a good chance that the winter of 2002-2003 would be warmer than normal; every part of the Northwest was at least 2F warmer than normal, and most of Idaho was 5F warmer than normal.
Columbia River Streamflow Outlook for 2003-2004: 15-Month Long-Lead Streamflow Forecast for the Columbia River at The Dalles for Water Year 2004, with different assumptions about ENSO and PDO.
The links below provide access to the latest information on the Current State of global and regional climate, as well as links to global and regional climate predictions.
1. The Current State of the Tropical Pacific
2. The Current State of the Globe
3. Predictions of Tropical Pacific
4. Predictions of US Weather
5. Special Areas: