What's Next for the Pacific Northwest?
Neutral El Niño-Southern Oscillation (ENSO) Conditions
Neutral ENSO conditions are still present in the tropical Pacific Ocean. During the last month, sea-surface temperatures (SSTs) have remained below normal in the central and eastern tropical Pacific Ocean, and are near-normal or above normal in the western tropical Pacific. The neutral conditions are expected to last through the summer. Models indicate that La Niña conditions will develop by the September through November period with about a 55-60% chance that the event will last through the winter of 2016-17. At this time, La Niña will likely be a weak event, and a "La Niña Watch" has been released.
What does this mean for Washington in the coming months?
The CPC autumn (September-October-November; SON) temperature outlook has increased chances of above normal temperatures for the entire state, with chances exceeding 40% on the three-tiered scale. For SON precipitation, there is little indication of how it will turn out over the course of the season. The CPC outlook is calling for equal chances of below normal, equal to, or above normal precipitation for the state.
The outlook for October-November-December (OND) is also indicating above normal temperatures statewide, but the chances are less than for the SON period. For the OND precipitation forecast, the anticipation of a weak La Niña is taken into account resulting in above normal precipitation expected statewide.
Remember that these outlook percentages are based on a tercile system, and therefore the chances of below, equal to, or above normal temperatures or precipitation are split into equal probabilities of 33%. When there is a greater than a 33% chance of an occurrence, it should be looked at as a slight tilting of the odds in favor of that outcome.
Last Updated: 8/18/2016
Climate Prediction Resources
NWS Local 3-Month Temperature Outlook
The links below provide access to global and regional climate predictions.