Northwest Growers Undaunted by Weather

Low-pressure system will be followed by El Niño weather pattern, expert says

by Peter Mitham
Flowers survived the May 31 storm at Tero Estates in Milton-Freewater, Ore.
Walla Walla, Wash.—It’s starting out as the Mark Twain vintage in the Northwest, where reports of vineyard damage seem to be greatly exaggerated—not unlike the famed humorist’s death.

Hail-battered blooms and frost-damaged buds are low on the list of growers’ worries as the 2015 season moves toward fruit set, with the long-term forecast calling for dry weather and an above-average crop.

This isn’t to say the past two weeks of storms from Lake Chelan to the Willamette Valley haven’t set growers on edge, coming on the heels of widespread reports of frost damage in vineyards across Oregon and southern Washington state.

Clive Kaiser, extension horticulturist in Umatilla County-Milton Freewater, reported in an update issued by the Oregon Wine Research Institute that a cold snap in November 2014 had resulted in significant bud damage in the Walla Walla Valley.

Similarly, Steve Castagnoli, Kaiser’s counterpart in Hood River, reported “spotty cold damage” in low-lying areas and among certain cultivars.

The stormy blast consequently put growers on notice, with Richard Funk of Saviah Cellars, north of Milton-Freewater on the Washington side of the state line, lending his “full attention” to the effects of a storm that blew through Eastern Washington this past weekend.

“We have had issues over the years with hail damage,” he told Wines & Vines. “Thankfully, the storm that moved through the valley (May 31) did not beat up our vineyard blocks, except a small fraction of leaves and shoots in the hardest hit area.”

Whether or not the damage is significant is another question. Funk said the various stages of bloom in the area mean growers will have to wait and see—an approach winemaker Doug Roskelley of Tero Estates winery is also taking.

The nature of weather means that there’s something for everyone, but not in equal measure.

Duane Wollmuth, a grower and executive director of the Walla Walla Valley Wine Alliance, was driving back from the Tri-Cities when the May 31 storm began, and it tracked east with them at 60 miles an hour.

“We had plenty of thunder and lightning on the north end of the valley, where my vineyard is located, but no hail,” Wollmuth said. “It was a dark and ugly one.”

Casey McClellan, winemaker at Seven Hills Winery in Walla Walla said his vineyards also appear to have escaped the brunt of the storm.

This isn’t to say yields won’t be down in some areas.

Drought and the threat of drought in many parts of Washington state and Oregon could translate into lighter, more concentrated fruit that reduces yields. This would compound the impact of any vineyards Mother Nature’s weather systems have thinned via frost and hail.

“There will be lower yields from some sites and some varietals, particularly Merlot and (in) low-lying areas,” McClellan said. “I expect my Merlot tonnage to be down a bit, but otherwise the vines look very fruitful, and I am expecting normal to above-average tons per acre.”

The precipitation is good news for reservoirs, however.

Roza Irrigation District shut down its irrigation canals in early May as estimates of available water slipped from 54% to 38% in the latter half of April (see “Northwest Growers Strategize to Face Drought”).

However, the storms of May replenished water supplies to 44% of normal by the end of the month. The taps in Roza turned back on this week.

Environmental science professor Greg Jones of Southern Oregon University in Ashland, Ore., warns growers not to count on ongoing humidity.

The storms of late May were the result of a low-pressure system that spun off over the region for a prolonged period mid-month.

“The result was clouds and moisture wrapping around the system for a prolonged period,” he reported, culminating in an “unsettled pattern…with spring thunderstorms, high winds and rain.”

But as an El Niño event takes shape through 2015, Jones told growers to expect warmer weather north from California into Oregon and Washington, accompanied by thunderstorm activity.

Previous vintages with similar patterns of weather include 1998, 2003, 2004 and 2005.

Notably, 2005 was the last year that drought afflicted Washington state, a year that began with a significantly larger snowpack than currently exists.

Similarly, further north in British Columbia, 2003 haunts the memories of grapegrowers as the year of smoke taint from the Okanagan Mountain Park wildfire that consumed part of St. Hubertus Estate Winery near Kelowna, B.C., and singed adjacent vineyards.

With dry conditions closing on both the Okanagan and emerging regions such as the Fraser River benchlands and Thompson River valley near Kamloops, winemakers are nervous.

Kathy Malone of Hillside Cellars Winery south of Okanagan Mountain Park in Naramata expressed concerns last month that arid conditions promise a repeat of 2003.

However, she told Wines & Vines that mercy may be in store instead.

Dry conditions are limiting the development of undergrowth, with inter-row crops in drip-irrigated vineyards already browning.

While this is uncommonly early, it also points to limited brush to fuel wildfire when hot, dry weather and thunderstorms combine.

“So maybe we’ll be spared,” she said.

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