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. The sea-surface temperatures (SSTs) in the equatorial Pacific Ocean are cooler relative to normal than they were last month. Over the last 4 weeks, SSTs throughout the equatorial Pacific Ocean have been near-normal for most of the area. A majority of the models continue to show neutral conditions persisting through the rest of the summer, fall (~65% chance), and winter (~55% chance).
What does this mean for Washington in the coming months?
With ENSO in a neutral state, the following forecasts from the Climate Prediction Center (CPC) are based primarily on forecasts from the dynamical seasonal forecast models, with decadal temperatures trends also coming into play.
The Climate Prediction Center (CPC) September temperature outlook has increased chances of above normal temperatures for the entire state. The highest probability of warmer than normal temperatures is in eastern WA, with the chances exceeding 50% on the three-tier system. The September precipitation outlook has equal chances of below, near-normal, or above normal precipitation for the month.
The CPC outlook for fall (September-October-November; SON) is calling for increased chances of above normal temperatures for the entire state and the entire country. The SON outlook calls for equal chances of above, equal to, or below normal precipitation for the entire state.
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: 8/17/2017
Climate Prediction Resources
NWS Local 3-Month Temperature Outlook
The links below provide access to global and regional climate predictions.