What's Next for the Pacific Northwest?
El Niño Conditions
El Niño conditions are still present, though there has been some cooling in the equatorial tropical Pacific Ocean over the last four weeks. Sea-surface temperature (SST) anomalies are still well above 2.5 degrees Celsius, however, and the El Niño is expected to persist through the northern hemisphere spring. The "El Niño Advisory" that was released on March 5 is still in effect, and the current El Niño is among the top 3 strongest El Niño events in the historical record. The exact ranking depends on the Nino indice that is used. Model consensus is extremely high that the El Niño will persist through the remainder of winter, with chances above 95%. Chances that the El Niño will persist through the spring have increased to about 85%, but by summer (June-August) neutral conditions are favored. The 3-month seasonal forecasts from the Climate Prediction Center are representing the tendency for El Niño winters to be warmer and drier than usual in the Pacific Northwest, particularly after the first of the year.
What does this mean for Washington in the coming months?
The CPC three-class February-March-April (FMA) temperature outlook has increased chances of above normal temperatures for the entire state, with chances exceeding 60% on the three-tiered system. For FMA precipitation, there are increased chances of below normal precipitation for the entire state, with slightly higher chances of drier than normal conditions for northern and eastern WA.
The outlook for spring (March-April-May; MAM) is very similar regarding temperatures: there are increased chances of above normal temperatures statewide. For precipitation, a majority of the state has equal chances of below, equal to, or above normal precipitation. There is a small area with higher chances of below normal precipitation in the northern Puget Sound, the islands, and the northern Olympic Peninsula for MAM.
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: 1/21/2016
Climate Prediction Resources
NWS Local 3-Month Temperature Outlook
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