As it relates to our vineyards the simple answer is no. All of the vineyards we source fruit from are above any flood plain and so are not at risk of flooding.
In general though flooding during the dormant phase has no real long term effect on the vines. Vines evolved in and around seasonal creeks, so they are accustom to some water. Occasional flooding can be beneficial as it deposits nutrients into the vineyard that have been depleted.
During the growth phase however, they typically do not do well with their roots under the water table. Oxygen in the root zone is critical for water and nutrient absorption. It is also important for beneficial micro-organism metabolism and respiration. Microbial activity such as organic matter decomposition and nitrification require the presence of oxygen in the soil.
With the amount of rain we have received and with no end in the forecast, the real concern becomes erosion and mudslides. The soils are saturated so most of the rain we continue to receive will not soak into the soil. This leads to overland flow which increases the risk of erosion and mudslides. In the worst situations, portions of vineyards can be washed away.
Assuming that the vineyard survives the rain, it shouldn't have an effect on this season's vintage.
Flooding at Hartford Winery
Flooding off River Road