Rejoice? La Niña is Forecast to End in the Pacific NW.
Word from the National Weather Service out of Pendleton, Oregon is that conditions in the Pacific Ocean are looking right to put an end to La Niña.
La Niña, also sometimes called El Viejo, or anti-El Niño, is when trade winds are stronger than usual in the South Pacific, pushing more warm water toward Asia. Off the west coast of America, an up-welling occurs, which brings more cold, nutrient-rich water to the surface. The cold waters of the Pacific then push the jet stream northward. All of this leads to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest. During La Niña year, winter temperatures are warmer than normal in the South and cooler than normal in the north.
Officials from the National Weather Service are forecasting trade winds to decrease to normal levels, which will bring warm water back east, causing the Pacific jet stream to move south of its current position. This phenomenon is referred to as El Niño. Typically this means a drier and warmer forecast for us here in the pacific northwest.
However, the effects of both the La Niña and the El Niño have a stronger affect on winter weather, though because of the change in pattern being forecast, we could very well see a hotter and drier spring and summer.
With that being said, we have been under La Niña conditions for the past three years. This has led to late snowfall in the past couple years, as well as several unusual cold snaps. The past few summers have also been punishingly hot and dry in the northwest, even under the La Niña conditions.
According to officials, just because we're transitioning into the El Niño pattern, doesn't mean even hotter and drier summers. Though it very well could lead to milder winters for the next year, or two. That can pose a problem for you own pest management come the next couple springs, but it is also a possible boon for our agricultural industry. The colder, wetter winters have been particularly tough for tree fruit growers. The early and late cold snaps can cripple those crops, as has happened the last couple of years. Though the prospect of a possibly drier late spring and early summer would be a blessing to cherry growers, in particular.