SEATTLE — The Climate Prediction Center has issued a La Niña Watch for the upcoming winter, but meteorologists say the signal is weak and may not bring the Pacific Northwest the classic La Niña weather pattern.
Forecasters expect a brief period of weak La Niña conditions this fall and early winter before the climate pattern reverts to neutral. La Niña, the counterpart to El Niño, is typically associated with cooler, wetter winters in the Northwest and drier, warmer conditions in the southern United States. But with only a faint signal developing, the National Weather Service in Seattle says the region may not see a clear influence on rainfall, snowfall, or storm activity this year.
Historically, La Niña winters have been mixed in the Northwest. The 2010–2011 La Niña brought heavy mountain snowfall, boosting snowpack and leading to above-average spring runoff. By contrast, the 2016–2017 weak La Niña produced only modest impacts, with precipitation and temperatures closer to average. Forecasters note that weak La Niña events are often the most difficult to predict, with some years showing little effect at all.
Officials emphasize that even with a weak signal, the potential for significant winter storms or flooding cannot be ruled out. Seasonal forecasts will continue to be updated as the region approaches the heart of winter.