On top of the frost warning tonight, it now appears that hail is in the forecast for later this week:
SCATTERED THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON AND EVENING. SOME OF THESE THUNDERSTORMS MAY PRODUCE LARGE HAIL AND DAMAGING WINDS...PARTICULARLY ACROSS NORTHERN AND CENTRAL VIRGINIA.
Hail storms are always a risk for vines, but the biggest risk comes primarily at the end of the growing season. The biggest risk to vines this early in the growing season is shoot damage, which is recoverable, but can take a lot of work.
Once again, all we can do is hope for the best.