I expect the grape leaves will fall since the low temperature predicted for today may be in the 20s.
GDD base 50 accumulated since April 1 = 3556
http://agebb.missouri.edu/weather/reports/gddTable.asp
Here is a comparison of the GDD base 50 accumulation for the past several years.
| Year | GGD accumulation base 50 April 1 to Oct 31 |
| 2014 | 3556 |
| 2013 | 3435 |
| 2012 | 4064* |
| 2011 | 3853 |
*Early grape bud burst in March – 4370 GDD in season if March is counted
(Grape bud burst usually occurs around April 1)