Warmer than average winter expected

Marcus Larson/News-Register##Painted hay bales guard the perimeter of Oregon Sweet Berry Farm, which is open 10 am-6 pm daily with loads of family friendly activities, such as hayrides, a corn maze, petting zone, rope swing and a slide.

This coming winter is likely to be warmer than usual, thanks to an exceptionally strong El Nino system, National Weather Service Warning Coordination Meteorologist Tyree Wilde told Yamhill County officials Thursday. But he said the agency is predicting a normal precipitation pattern.

Every year, the county’s Office of Emergency Management asks Wilde to come in to present a forecast. And it invites law enforcement, transportation, health, social services and public works personnel to sit in.

A warning that the winter is likely to be unusually wet sometimes prompts early sandbag purchases to avoid later shortages. Predictions of severe cold can persuade homeless shelters plan ahead for extra capacity.

Typically, El Nino conditions result in warmer, drier conditions in the Pacific Northwest, as storms split and pass to the north and south of Oregon.

That’s not good news for Oregon, all of which is currently in severe to extreme drought, though it might bring some relief to drought-ravaged California, Wilde said. Even a winter of heavy rainfall wouldn’t erase California’s extreme drought conditions, he said, but it would help.

Last year was the warmest on record for the Northwest. In marked contrast, the Eastern Seaboard experienced one of the coldest, snowiest winters on record.

But Wilde noted El Nino provides no warranties against storms. He said some El Nino years have produced severe storms, and sometimes even higher-than-normal rainfall.

Given Oregon’s depleted subsoil moisture conditions, that might prove a boon for farming and fish and wildlife interests, he said.

Since 1950, Wilde said, there have been six strong El Nino episodes. Four resulted in below-normal precipitation, one near-normal precipitation and one above-normal precipitation.

He’s predicting near-normal this time.

The effect on winter snowpacks remains to be seen. Last year, warm temperatures in the mountains resulted in record-low snowpacks that dissipated too early to do much good. That was true to some extent in most western states, but most pronounced in Oregon, he said.

 This year, he said, “The odds are it won’t be as bad.” Nonetheless, he said, “The snowpack is likely to be below average.”

Conditions were exacerbated by a dry spring and hot June, blamed on an unusually warm water mass that developed in the Pacific.

Models show it is likely to be relatively warm and dry in October, November and December, but that precipitation should rebound in January, February and March.

Flooding, windstorms and valley floor snowfall aren’t likely this year, Wilde said.

But he noted, “You can always expect at least one significant event in any year.” He also noted, “We tend to get more snow in a strong El Nino year than in a weak one.”