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Climate report keeps Oregon wine industry warmly optimistic

By Eric Degerman on July 4, 2013

David Hill Vineyards and Winery in Forest Grove, Ore., features some of the oldest plantings in the Willamette Valley. (Photo courtesy of Jason Bull)

Vineyards in the Willamette Valley, including David Hill Vineyards in Forest Grove, Ore., can expect to see above-normal temperatures during the first three weeks of July. (Photo courtesy of Jason Bull)

ASHLAND, Ore. – The recent weather report issued by Southern Oregon University professor Gregory V. Jones, widely viewed as the world’s leading expert for climate studies of viticulture, has the Oregon wine industry increasingly optimistic for the 2013 vintage.

“Combining this with the condition of our vineyards and the fact we are three weeks advanced phenologically generates excitement,” said Jones’ father, Earl, owner and founding winemaker of Abacela in Roseburg.

Most wine grape growers in Oregon wield precise control over irrigation, but warm weather and the all-important growing degree days are out of their hands. According to Jones’ report, vineyard managers in Oregon and throughout the Pacific Northwest can expect above-average temperatures this summer.

Oregon wine industry can expect more of same this summer

“The 30- to 90-day forecasts through late-summer (July-Aug.-Sept.) are showing the western US to have a continued greater likelihood of being much warmer than normal with drier than normal conditions, especially over the PNW,” Jones wrote.

His research includes data from the Climate Prediction Center, based on work by the National Oceanic and Atmospheric Administration and the National Weather Service, which monitors and forecasts short-term climate fluctuations and provides information on the effects climate patterns can have on the country.

Jones, whose work continues to elevate the Department of Environmental Studies at the Ashland school, pointed out that the month of June perpetuated a warmer growing year in 2013, particularly in Oregon.

Growing degree days in Oregon above 10-year average

“For those in Oregon, our June growing degree-day numbers have continued their above normal trend, running 13-25% above the average of the last 10 years, while year to date precipitation is down 35-50%.”

Jones’ data for McMinnville in the Willamette Valley showed the cumulative growing degree days reached 733 at June 30, which is above the 30-year average (620) and nearly double that of the pace during the cool 2010 vintage (396). It is even slightly beyond those of 2003, a recent warm year, which had compiled 725 GDD before July 1.

In the Roseburg region of the Umpqua Valley, the cumulative GDD reached 1,044 at June 30, which is well above the 30-year average (790) and the pace of the cool 2010 vintage (618).

In the Milton-Freewater portion of the Walla Walla Valley, the 1,044 on June 30 is closer to the 30-year average (910), well above the 2010 vintage (743) and even beyond the 977 of a recent warm year in 2003.

Greg Fries, President of Duck Pond Cellars in Dundee, Ore., and Desert Wind Winery in Prosser, Wash., has large estate vineyards in both states was on the road this past week look at vineyards.

“I was in Milton-Freewater on Tuesday and Roseburg (Thursday),” he said via email. “It’s kind of apples and oranges, but I did notice canopy and berry sizes very similar. I’m a little surprised at the lag I see at our vineyards in Salem vs. the GDD data. I think the cool, wet weather catching us at bloom there threw a wrench into things. The Dundee site is more on track.”

Report indicate Pinot Noir in the Willamette Valley was slowed by that cool, wet weather, but it is highly dependent on elevation, with some low sites way ahead and some higher sites way behind, Jones said.

The report by Jones showed temperatures in June were as much as 3.5 degrees Fahrenheit higher than normal in most of Oregon and California.

In some areas of Washington state, however, temperatures were normal or slightly below normal. And precipitation in portions of the Columbia Valley also was above normal, which hampered much of the region’s often-lucrative cherry harvest.

“Areas of northern California and central Oregon up into eastern Washington saw some substantial rains during a few storms events during the month,” Jones wrote.

Conditions in the Pacific Ocean are responsible for the climate in the Pacific Northwest.

“There has been no drastic change in the sea surface temperatures over the equatorial Pacific while warmer ocean temperatures off the west coast are continuing to develop,” Jones reported. “Coupled with the summer time Pacific high pressure ridge developing into its normal position, the latest guidance from the Climate Prediction Center suggests a continued trend toward drier and warmer across most of the West Coast and the Southwest.”

That’s continued good news for the Pacific Northwest wine industry, which looks to grow production to satisfy consumers around the globe.

Most of July expected to be warmer, drier than normal

And in the short term, expect most of July to feel like the first few days of the month, Jones predicted.

“The current CPC short-term forecasts (6-10 and 8-14 days) through the third week in July are calling for a much greater likelihood of above normal temperatures and below normal precipitation across the western U.S.,” he wrote.

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About Eric Degerman

Eric Degerman is the President and CEO of Great Northwest Wine. He is a journalist with more than 30 years of daily newspaper experience and has been writing about wine since 1998. He co-founded Wine Press Northwest magazine with Andy Perdue and served as its managing editor for a decade. He is a frequent wine judge at international wine competitions throughout North America and orchestrates 10 Northwest competitions each year.