As of now
There are reports of smaller crop sizes. Some of this has to do with the spring weather thinning out the crop; some of it may be more of a natural response to three straight years of very large yields.
A smaller crop size does not mean lesser quality. It can actually mean the opposite (but that's not guaranteed either).
The growing season is a couple weeks earlier than average. This has been the norm through the drought as spring has started early for the past few years. This year the grape growth cycle looked very early for awhile, but a coolish May slowed things down. June and July have been all over the place -- some very cool weather followed by hot spells. Even a couple rainy days and it "never" rains in the summer. Doesn't seem like many days have just been average.
For the rest of the season
First, if I could predict the future I'd be rich (I'm not).
The weather in the Pacific is looking like the start of a strong El Nino year. This means lots of rain for California -- maybe even more than we actually need. It could start raining much earlier in the year. Rains generally hold off until about November after the grapes are harvested avoiding those problems with mold and unripe fruit. If it starts raining in earnest before all the grapes are in there could be problems. Some growers are thinning their crops in hopes of ripening what is left earlier before any potential rain storms. (The less fruit to ripen, the faster is will ripen).
|Dropped fruit in the cool 2014 growing season in Tuscany|
Image from rebeccawineintuscany.com
Yeah, if you're a farmer you spend a lot of time worrying!