Hail Damages Crops, USDA Responds, Growers Alerted to Fire Blight Danger

PROSSER, Wash. – While Washington has been spared the devastating droughts and fires that farmers and ranchers in other parts of the nation are contending with, the region has experienced damaging storms. The USDA reports that U.S. Department of Agriculture Secretary Tom Vilsack is using his authority to flex programs in order to provide relief for those affected. In counties not designated disaster areas, individuals who have suffered at least a 30 percent loss in crop production or a physical loss to livestock, livestock products, real estate or chattel property may be eligible for emergency loans.

Impact craters in soil caused by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.
Impact craters in soil caused by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.
Hail stones. Photo courtesy Mike Doerr.
Hail stones. Photo courtesy Mike Doerr.

“This provision may be especially applicable due to this season’s thunderstorms, which caused isolated damage throughout the state,” said Farm Service Agency State Executive Director Judy Olson.

Assessing the damage

A field of corn damaged by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.
A field of corn damaged by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.

WSU Extension educator Tim Smith said that the state’s tree fruit industry has been hit by a series of thunder and hail storms. “We were sitting on a great crop of apples,” he said. “We think there are still a lot of good apples out there, but we won’t know the full extent of the damage for at least a couple weeks.”

Smith said that fieldmen would take at least a week to assess damage in their growers’ orchards. That data would then be collected by packing houses, which would then present their cumulative findings to the industry.

Farmers warned of fire blight

Many orchards sustained damge by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.
Many orchards sustained damge by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.

Smith emphasized the need for producers to be on the lookout for fire blight in blocks known to be already infected with the disease. “If there already was fire blight in a block, the wounding caused by the hail and the wet conditions generally are conducive to the spread of fire blight,” he said.

Smith, an internationally recognized expert on fire blight and its management, said that producers should be on the lookout for symptoms of fire blight 10-14 days after the latest hail event. “Growers can save trees by cutting out infected branches,” he said.

Rare weather convergence

A vineyard damged by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.
A vineyard damged by hail. Photo: Gerrit Hoogenboom/WSU. Click image to download hi res version.

“Many locations across eastern Washington had strong storms last Friday,” said Nic Loyd, WSU AgWeatherNet meteorologist. Loyd said there was a rare weather pattern that resulted in a convergence of factors resulting in the damaging weather. “These factors include warm air, moisture — the fuel for the storms — an unstable low-pressure system, wind shear, and a dynamic cold frontal passage that acted as the trigger. The resultant weather included severe thunderstorms that featured strong winds, heavy rain and flash flooding, lightning and large hail in some places.”

Because the convection cells that form thunderstorm clouds are relatively small, not every location received notable weather. For example, the AgWeatherNet station at Sunnyside recorded nearly three-quarters of an inch of rain in a mere fifteen minutes on Friday, while nearby locations received no rainfall at all. Loyd explained that storms are more likely to form over mountains or hills, since the sun-warmed ground on a hilltop is surrounded by cooler air and is thus more unstable than the air at the valley floor.

The size of the hail that damaged crops last Friday was due in part to the strong convection cells that formed that day. A convection cell forms when there is a strong gradient, or difference, between hot and cold fluids (the Earth’s atmosphere behave much like a fluid). “As warm, moist air rapidly rises in an unstable environment, condensation occurs and creates large thunderstorm clouds. If the updrafts in the storm are strong enough, large hail can form in the cold air that is present high in the atmosphere. As gravity pulls the hail downward, updrafts force the hail upward yet again and allow greater amounts of water to freeze to the hailstone before it ultimately falls to earth.”

Report weather-related damage

Olson reminded farmers and ranchers to report weather-related damage to the U.S. Department of Agriculture Farm Service Agency. “USDA uses damage reports to determine a need for disaster declarations,” she said. “Damage reports are not limited to crops. They also include farm structures, farmland and livestock,” she explained. She encouraged farmers and ranchers to contact FSA county offices to report damages and inquire about assistance from USDA.

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