As of 1:30 p.m. EST, it is raining in Blacksburg, Va. and has been for much of the morning. If weather.com is correct, it will continue off and on until the 5 o'clock hour, and pretty much be done by gametime. With the front having gone through, the temperature will also drop to around 45 degrees at kickoff.
How does this affect the game? Two things immediately come to mind, the first being that the wet day and cold weather will help to quiet down the crowd. The other is that Georgia Tech's offense has played well in rain and bad weather before, with two games in particular: 2008 Georgia and 2009 Virginia.
A wet field could help slow down Virginia Tech's high powered offense, which has scored over 40 points in 4 straight games. Tech's defense which has struggled at times this season could use any advantage it can get.
The only worry is that Tech's triple option, which is based on timing and precision, is thrown off by the conditions and the Jackets put the ball on the ground more than normal.