A camera attached to the dashboard of a car driving northbound on the Jones Falls Expressway into Baltimore County shows the effects of Sandy have already begun to hit the area.

UPDATE: The pending arrival of Hurricane Sandy this week has prompted Baltimore County Public School system to close schools and offices at least through Monday.

Baltimore County Executive Kevin Kamenetz warned at a press conference Friday afternoon that the county expects Hurricane Sandy’s landfall to be a “very, very serious event” that could leave portions of the state without power for days.

“Be prepared to be without power for a long period of time,” Kamenetz said. “No one likes that scenario, but if trees start coming down — which is likely — we have to be realistic. Homes and businesses may be without power for a period of days, a number of days.”

According to the county’s latest forecasts, Kamenetz said he expects weather conditions to begin deteriorating on Sunday, with tropical storm-force winds and rain beginning on Monday.

“The concern that we have about this particular event is the duration of it, which would continue through Thursday,” Kamenetz said.

BGE Vice President of Corporate Communications Rob Gould acknowledged that, “the real belief that this storm could actually be worse than what we saw with Hurricane Isabel and with Hurricane Irene.

“That’s a pretty dire prediction if that comes true,” Gould said.

Gould said BGE began contacting customers via a robo-call urging them to prepare, and has requested 2,000 out-of-state utility workers to supplement its 3,000 in-house employees and 1,500 contractors.

So far, Gould said between 500 and 800 workers have committed to the effort, with many east-coast utilities holding on to its employees until its own interests are taken care of.

BGE will stage the utility workers at M&T Bank Stadium, Ripken Stadium in Aberdeen, BWI, and the Maryland State Fairgrounds in Timonium.

According to a news release issued Friday, BGE expects “several thousand” customers to be left without power.

As a result of what could be a prolonged storm in which cleanup efforts might not commence for days after the storm hits, Kamenetz and other county officials urged residents to follow the county’s mantra of preparing for the worst and hoping for the best.

“This is the time for preparedness and planning,” said Assistant Fire Chief and Director of Emergency Management Mark Hubbard. “If there’s any good news to this scenario, it’s that we have advanced warning. We can see it coming.”

With that in mind, Kamenetz and other officials encouraged residents to stock up on water, non-perishable food and other essential items. Residents should also charge all electronic devices, check on elderly or at-risk neighbors, check generators and ensure they’re placed in well-ventilated outdoor areas, and have an evacuation plan.

Several county agency heads detailed their departments’ preparations in anticipation of the storm.

Police Chief Jim Johnson said extra police officers would be on patrol during the storm, and he reminded residents that should traffic signals go dark during the storm, residents should treat all intersections as four-way stops.

“We encourage our motorists, at a certain point when it becomes too dangerous, do not drive,” Johnson said.” If you must operate a motor vehicle, do not … move through standing water.”

Fire Chief John Hohman said the county’s 25 career and 32 volunteer fire stations have checked equipment and are preparing for the worst, especially in low-lying and coastal areas.

Kamenetz said county government would also be in contact with the state Board of Elections over the coordination of early voting sites, which open on Saturday.

For up-to-date information on Hurricane Sandy from Baltimore County emergency officials, visit www.baltimorecountymd.gov/emergency or follow @BACOEmergency on Twitter.