The talk in the Northern California wine community has been all about frost this spring. I know in our area there is anywhere from 10-100% loss from the night-after-night freezes we've had in the past few months. I'll put it this way - we've turned on our overhead frost-protection sprinklers more times this year than the past two years, combined!
Hillside vineyards that normally don't frost because the cold air filters down onto the valley floor have been hit especially hard, as many don't have any frost protection measures at all (well, would you bother if this is the first time in 30 years that you had to worry about it?). Here on the valley floor, we've been so cold - in the mid-20s too often - that wherever multiple sprinklers don't overlap, the baby leaves are burnt to a brown, brittle mess. And that includes the developing flowers, which will never turn to grapes as they're now completely dead.
Mendocino County is now asking all its growers to send in information about their damage this year, as they're considering asking for federal emergency money for the crop, which is looking to be very low.
I'll post some pictures soon. It's not pretty.