SPOKANE — Pacific Northwest farmers will see a dry winter and a wet spring as an El Niño forms in the Pacific Ocean, a weather forecaster says.
Art Douglas, professor emeritus in atmospheric sciences at Creighton University in Omaha, Neb., told farmers they will see three months of dry weather this winter.
Speaking at the Tri-State Grain Growers Convention, Douglas said a ridge of high pressure caused by high ocean surface temperatures will persist off the West Coast. The condition is favorable for developing an El Niño. El Niño refers to unusually high surface temperatures in the Pacific Ocean near the equator and usually indicates dry conditions for the Pacific Northwest.
Douglas also predicted dry winter weather in Arizona, California and eastern portions of Oregon and Washington, with at best 80 percent of normal precipitation in eastern Washington and 65 to 75 percent of normal precipitation in eastern Oregon.
“I’m not real hopeful for precipitation in the winter,” he said. “The area that is really going to be hurt is California. They only have about one year of irrigation water left in their reservoirs right now, so if they have a dry winter that’s probably going to run at best 50 percent to 75 percent of normal precipitation, they’re going to have really bad conditions in terms of irrigation.”
Douglas also predicted:
• Dry fall conditions leading into winter after one of the wettest Septembers on record, caused by a complete reversal of the jet stream pattern, with a trough off the Pacific Northwest coast from the Gulf of Alaska replaced by a ridge of high pressure in October.
“We can see that drought has spread a little further north into eastern Oregon, as well Idaho and portions of western Montana,” Douglas said.
• A dry December in the Northwest. The ridge gets closer to the coast in January, so even drier conditions will prevail.
• March will bring above-normal precipitation — about 150 percent of normal in eastern Washington. Idaho will see 110-120 percent of normal precipitation and the rest of the spring will be wet. Dry conditions will continue in eastern Oregon and western Idaho. California will remain dry, and Douglas said water rationing there is a likelihood.
Douglas said summer will be wetter than normal, especially in June, and slightly warmer than normal.
He often compares the outlook for the coming year with similar weather patterns in previous years, so farmers can revisit their notes about those years. He said 2013 looks to be most similar to 1970, 2006, 2011 and 2012.