Climate Outlook
What’s Next for the Pacific Northwest?
Neutral El Niño-Southern Oscillation (ENSO) Conditions
On September 10th, the Climate Prediction Center (CPC) upgraded the La Niña Watch to a La Niña Advisory due to sea surface temperatures (SSTs) dropping to -0.9˚C in Nino 3.4 (5°N-5°S, 120°W-170°W), which is below the La Niña threshold of -0.5˚C. The advisory is issued when La Niña conditions are present and are expected to persist for five or more consecutive months. La Niña conditions can also be observed in the tropical atmospheric circulation. Since the start of the month, SST anomalies have amplified with above normal SSTs in the western equatorial Pacific and below normal SSTs in the eastern equatorial Pacific. The four Niño regions, which range from 170°E to 90°W, have all undergone cooling over the past month- resulting in negative SSTs. Since the last climate outlook, ENSO models have pointed towards an elongated La Niña event lasting through winter. Previously, models were indicating a weak La Niña dissipating in the winter months. ENSO models show a fair amount of confidence with a 65% chance of La Niña between January and March, when ENSO is typically strongest.
What does this mean for Washington in the coming months?
The CPC October temperature outlook has equal chances of above,
below and near-to normal temperatures giving little insight into the month to
come. The precipitation outlook has increased chances of
above normal precipitation statewide in the 40 to 50% range.
The CPC three month (October-November-December) temperature outlook has slightly favored conditions for above normal temperatures statewide. Above normal precipitation is favored statewide during this time period with greater chances in the 40 to 50% range outside of the SW Washington and the Olympic Peninsula. Drought conditions in the Columbia Basin are expected to improve through the rest of 2020, with drought conditions disappearing on the periphery of the affected area.
Last Updated: 9/18/2020
Climate Prediction Resources
NWS Local 3-Month Temperature Outlook
Select a location plotted on the map to view the local outlook.
The links below provide access to global and regional climate predictions.
- The Current State of the Tropical Pacific:
- Predictions of the Tropical Pacific:
- Predictions of U.S. Climate Anomalies
