CORVALLIS - Long-term weather predictions sometimes are a shaky proposition and forecasters who last year predicted a wet and cold winter ended up with egg on their face. It was one of the driest winters in a century.
So when Oregon State University's George Taylor - the state climatologist - issued his winter weather forecast Friday calling for an "average" winter, it seemed like a safe prediction.
Taylor insists he isn't getting gun-shy. It just "looks like an average year," he said.
"All-in-all, we expect generally average temperatures in the fall and winter, with maybe a little more precipitation than normal, and average mountain snowfall," said Taylor, who is on the faculty of OSU's College of Oceanic and Atmospheric Sciences.
"I'd say there is a 50-50 chance of one or more big snow events in the western valleys," he added. "Historically, we receive snow storms about 50 percent of the time, so again, it looks like an average year when it comes to the possibility of snow at low elevations."
Meanwhile drought conditions continue to plague the Pacific Northwest. The dry winter last year has led to a disturbingly low water supply, lowered moisture content in forestlands, and created dangerous wildfire conditions.
Fall relief is drawing closer, Taylor said, though it may not get here for another six weeks.
"The fall-winter 'wet season' should arrive about on schedule," he pointed out. "In Oregon, October is the biggest transition month; it usually begins mild and dry and ends wet and cool. Often, that transition is rather abrupt, but it probably won't come until mid- to late-October."
For the next six weeks or so, Taylor sees below-average precipitation and warmer-than-average temperatures - not good news for firefighters. The rainstorm that hit earlier this week helped douse existing fires, but did little to change water supplies. And the benefit of additional moisture in the soil likely will be wiped out by increasing temperatures over the next few days.
When winter storms arrive in mid-October and November, Taylor said, precipitation in both western and eastern Oregon should return to normal. Days will be generally cool; nights mild.
The best chance for snow in the valleys, Taylor said, will be in late January or early February. Eastern Oregon may experience temperatures that are cooler than normal in mid-winter, and slightly wetter than average in March.
"November and January look like they may be the wettest months, and those 'pineapple express' storms coming from the southwest may bring some abundant moisture to southern Oregon," Taylor said.
Unless, of course, we have another dry winter.
"Last year, the forecast bombed," Taylor said with a laugh. "It is as simple as that. But we were in good company, because nobody foresaw a dry winter, let alone a near-record dry winter. There is no good explanation for the extreme dryness. We're still puzzled by what happened. We can't blame it on El Nino or La Nina or other known causative factors.
"If we saw last August's conditions again, we would probably predict near-normal precipitation again," he added. "And we would be wrong again."
Taylor's best guess? A strong trough of low pressure over the Midwest last winter brought very cold temperatures to the eastern U.S. and caused a ridge of high pressure in the west, which diverted storms away.
"That was definitely not an average winter," Taylor said.
Click photos to see a full-size version. Right click and save image to download.
George Taylor, 541-737-5705