‘Slow and steady harvest’ forecast for Northwest grapes in 2019

By on September 4, 2019
If the forecast holds true, the 2019 vintage is shaping up to be one of quality without any major weather events involving harvest on the horizon. (Richard Duval Images)

The 2019 vintage has entered the homestretch in the Pacific Northwest, and the weather forecast seems to indicate that vineyards are positioned for essentially an uneventful hand-ride through harvest.

Greg Jones, a professor at Linfield College in McMinnville, Ore., and one of the wine world’s leading climate researchers, pointed to rather favorable conditions for the Northwest wine industry in his Weather and Climate Summary and Forecast for September.

“The 2019 harvest is underway in many regions, with sparkling varieties and other early ripening varieties picked across the west,” Jones wrote. “Reports also indicate that mid-month may be the center of the harvest, but the forecasted mild and dry conditions should allow for a slow and steady harvest window.”

While the 2019 vintage is lining up similar to that of the past two years in terms of growing degree days, better yet, most of the vineyards throughout the Northwest have not been subjected to smoke from wildfires, particularly in Southern Oregon.

“Heat accumulation (GDD) amounts for four locations that I have tracked for many years in Oregon continue to track near last year’s numbers but below the last few years,” Jones wrote. “Locations in the Willamette Valley, the Umpqua Valley, the Rogue Valley, and the Walla Walla Valley are currently 10-25% above the 1981-2010 normals for the months of April through August and from the same to 6% lower than the same point in 2018.”

Jones, hired in 2017 to become the director of the Evenstad Center for Wine Education and Evenstad Chair in Wine Studies at Linfield, also noted that August didn’t bring a broiling string of 100-degree days, which was a characteristic of the record-hot 2015 vintage. Wine grape vines start to “shut down” when temperatures reach about 95 degrees. 

“A moderately warm August, but low heat stress compared to recent years,” Jones pointed out. “The month was dry south and slightly wet north, but concerns for drought conditions in the PNW and fire risk across the west continue.

Heat units track near 2018, 2017

Greg Jones, a professor at Southern Oregon University and one of the wine world's top climate experts, presents his annual report Feb. 14, 2017 at the Idaho Wine Commission annual meeting in Boise.
Greg Jones, a professor at Southern Oregon University and one of the wine world’s top climate experts, shares his Weather and Climate Summary and Forecast each month with the Pacific Northwest wine industry. (Photo by Eric Degerman/Great Northwest Wine)

Despite the cold and snow of February, growing degree day charts throughout the Pacific Northwest were headed in record territory soon after April 1. A cool June changed that, and the moderate August is reflected in weather stations monitored by Jones throughout Oregon wine country and tracked by Washington State University’s AgWeatherNet across its 177 stations.

At this point, the hottest growing region is Washington state appears to be the Wahluke Slope. Through Aug. 31, there were 2,869 growing degrees days recorded at the Wahluke Slope station. A year ago, that total was 3,046. In 2017, it charted 2,956 GDD. During the broiling 2015 vintage, it stood at 3,331 when September began.

At the Benton City station near Red Mountain, there were 2,791 GDD – while it was 2,909 GDD a year ago. In 2017, it read 2,829. In 2015, there were 3,173 GDD when dusk fell Aug. 31.

On Snipes Mountain in the middle of Yakima Valley, there were 2,634 GDD registered. A year ago, it was 2,831 GDD. On that date in 2017, the accumulation stood at 2,721 GDD. During the blistering 2015 season, it was 3,103.

In the Horse Heaven Hills, the station at Phinny Hill picked up 2,611 GDD by Aug. 31. A year ago, it was 2,622. In 2017, it was 2,500. In 2016, there 2,581, but in historically hot 2015 – the first year of that device near famed Champoux Vineyards – it captured 2,792 GDD.

The Pullman school’s 21 Acres station in Woodinville collected 1,551 GDD, compared with 1,645 of a year ago and 1,523 GDD from 2017. Back in 2015, it received 1,820.

In the Columbia Gorge, Skamania County’s Stevenson station notched 2,138 GDD. A year ago, it stood at 2,293, while in 2017 it counted 2,166. During the scorcher of 2015, however, it had reached 2,438 to start September.

In the Walla Walla Valley town of Milton-Freewater, Ore., there were 2,694 GDD through Aug. 31. Last year, it was 2,865. In 2017, there were 2,890 GDD. In 2016, it read 2,673. At the same stage in the record-hot vintage of 2015, there were a whopping 3,162 growing degree days.

In McMinnville, the home of Linfield College and the heart of Willamette Valley’s Pinot Noir territory, there were 1,863 growing degree days to start September — which is well ahead of the 1981-2010 average but well off the 2,187 of 2015. Last year, it stood at 1,859. In 2017, the figure was 1,954. In the 2016 vintage, seen as a glorious season for Pinot Noir, it was 2,059 to start September.

This year, Roseburg started September at 2,474 GDD, which matched that of 2018. In the historically hot 2015, there 2,734 GDD recorded. And the Rogue Valley station in Medford recorded 2,699 GDD. Last year, the total was 2,755. In 2017, it already hit 2,888.

“Heat accumulation continues to lag behind the warmest of the last few years but remains largely above average in all but portions of the northern and southern coast of California and eastern Washington, which are closer to average or slightly below average,” Jones wrote.

Harvest for bubbles, whites wine well underway

Grapes from the 2019 vintage for white wines and sparkling programs began arriving in Washington’s Yakima Valley during the third week of August. (Richard Duval Images)

Treveri Cellars, the Yakima Valley’s award-winning sparkling wine house, brought in Pinot Blanc and Pinot Meunier from its young estate vineyards on Aug. 21.

Woodward Canyon Winery in the Walla Walla Valley began its crushing season with Chardonnay on Sept. 2. A year ago, the Small family kick-started harvest on Aug. 22 with Sauvignon Blanc.

“The forecast through mid-month indicates a warm start to September becoming mild through mid-month then warming to slightly above average later in the month with no major heat events,” Jones wrote. “Some precipitation is forecast for the extreme northwest, but not much expected, while the rest of the west will likely stay dry.”

Jones signaled “very warm” waters in the North Pacific Ocean as the driver for September through November, “with the western U.S. likely seeing a warmer than average end of summer and start to fall.”

At this point, drought remains a concern because there are no major rain events on the horizon. 

“A relatively dry water year to date continues in northwestern Oregon and Washington and some scattered areas in the northern Rockies (60-85% of average),” Jones wrote. “The U.S. seasonal drought outlook shows continued concern for short to long-term drought in the PNW, especially western Washington, northwestern Oregon and the northern Cascades.”

However, the rest of the U.S. may be more envious than usual of the Pacific Northwest.

“The inland PNW is the only area in the West, and the entire country, forecast to see below-average temperatures,” Jones wrote.

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.

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