Absentee voting is way down in Virginia this year compared with 2008, and that could be reduced further by Hurricane Sandy, which shut down polling places across Northern Virginia and the Eastern Seaboard on Monday.

About 246,000 Virginians have cast ballots so far this year. That's 100,000 fewer ballots than were cast at this point four years ago and just half of the total cast in the 2008 election, according to the Virginia Public Access Project, a nonpartisan election watchdog.

All but three localities experienced a decline in early voting. In voter-rich Northern Virginia, the drop-off ranged from 15 percent in Loudoun County to 35 percent in Fairfax County, even though those are two counties in which the presidential and Senate candidates have focused much of their time and resources.

Early voting is down statewide, in regions crucial to both Democrats and Republicans.

Richmond, which heavily favored Obama in 2008, is seeing a 41 percent decrease in absentee voting this year. Early voting in neighboring Chesterfield County, which voted for Republican candidate Sen. John McCain in 2008, is down 61 percent.

Virginia is not a traditional early-voting state. Voters who wish to cast absentee ballots must have an approved excuse, such as military duty or a disability.

Still, 13 percent of Virginians voted before Election Day in 2008, and the presidential campaigns were hoping to generate similar levels this year. President Obama in particular made early voting a priority four years ago en route to a historic victory in Virginia, and his campaign has focused on it again this year.

Hurricane Sandy is sure to further hamper efforts to pump up early voting. The storm partially or completely shut down polls Monday in about 20 communities including Arlington, Fairfax, Prince William and Loudoun counties, as well as the cities of Fairfax, Arlington and Falls Church in Northern Virginia.

Gov. Bob McDonnell and the State Board of Elections are exploring options to keep polls open longer later this week to compensate for storm-related interruptions. The state is now allowing in-person absentee voting for those affected by the hurricane or workers away from home helping with relief efforts. Those affected only by rain don't necessarily qualify to vote early, McDonnell said.

"This is not a blanket authority for people to vote early," McDonnell said. "Those conditions still have to be met. Those rules haven't changed."

The number of registered voters, however, is up across the state, particularly in exurbs of Loudoun and Prince William counties, where registration is 15 percent higher than in 2008. Traditionally Republican southwest Virginia has seen little increase.