From NPR:

When rain soaked Napa Valley two weeks ago, Bruce Cakebread — the president of Cakebread Cellars in Rutherford, Calif. — used a technique occasionally employed by orange and cherry farmers. It's just the latest example of farmers forced to take drastic measures to salvage crops in the face of extreme weather.

If mold forms on grape clusters, they can't be picked for harvest. Fortunately for the valley's winemakers who got drenched this month, most of the white and red varietals had already been picked, Cakebread tells The Salt (NPR's Food Blog). But the Cabernet Sauvignon — a tougher, more resilient varietal — still hung on the vines during the wet weather.

Cakebread's hired helicopter snaked up and down 100 acres of vineyard about 20 feet above the valley floor, using the wind from the chopper's blades to push water off the plants. You can watch the video:

For complete story, see: To Save Soggy Grapes, Winemaker Looks To Helicopter