ENTERPRISE — For hunters, firefighters and farmers, the Oregon Department of Agriculture fall weather forecast, September through November, could hardly be better — colder than normal and wetter than normal.
“Look for fall to come in in a big way in mid-September,” ODA meteorologist Pete Parsons said. “That might make for a quick end to the fire season, but it also could cool things off in a hurry.”
Parsons expects that colder waters in the tropical Pacific off South and Central America will push us into La Nina conditions, which generally mean a cold wet winter.
“We’re going to have different jet stream patterns this fall and winter than we’ve had the past couple of winters,” he said. “And the blob of warm water that’s been in the Gulf of Alaska has moved farther offshore. That means we’ll have cooler waters along the coast, and that, too, will lead to cooler weather here.”
Parsons said while September is typically nice, Northeast Oregon could be looking at temperatures almost 4 degrees below normal, along with 252% of normal precipitation.
“We may see leaves turn a little quickly, along with some storminess that has a little more punch to it,” he said.
October may be closer to normal, with temperatures only about 1 degree below normal in Northeast Oregon, according to Parson’s long-term forecast. But precipitation, at 128% of normal, may mean a slightly soggier-than-usual month for Wallowa County.
Northeast Oregon’s November may be slightly below normal in both temperatures and precipitation, Parsons said, with a high-pressure ridge forecast to form over the Northwest that presages slightly drier-than-normal weather during the month.
“It is possible to get an outbreak of colder air into the northern parts of Oregon during November,” he cautioned. “The more ocean conditions trend toward La Nina, the better the chances of getting a mountain snowpack start to build up around Thanksgiving.”
The outlook after the November holiday tends to lean toward cold and wet, Parsons said.
“There’s a real good chance of at least one Arctic outbreak this winter, so get ready for some cold, snowy weather, especially in the mountains,” he said.