(CNN) -- States up and down the East Coast are preparing for Hurricane Sandy, which has sent rain to portions of North and South Carolina. Sandy could strike the U.S. coast anywhere from the North Carolina-Virginia border to Connecticut, a 700-mile stretch where state and local authorities are rushing to prepare for potentially devastating effects.
From north to south, here is a look at how coastal states are getting ready:
The Maine Emergency Management Agency is warning that Sandy has the potential to create "significant problems" in the state, starting Monday. The concerns range from high surf to strong winds to coastal erosion, the agency says.
In anticipation of widespread power outages, Gov. Paul LePage signed a "limited emergency declaration" so power crews from other states and Canada can help the state prepare for Sandy. The declaration also extends the hours that power company crews can drive.
Gov. John Lynch joined local and state emergency management officials on a conference call to discuss preparations for the storm. The governor also is discussing preparations with the state's utilities, according to his office.
Sandy could bring winds of up to 60 mph and between 2 and 4 inches of rain to parts of the Granite State, likely starting Monday, the governor's office said.
"While the exact path and severity of the storm remain uncertain, it is clear New Hampshire will experience a significant weather event and I urge everyone to be prepared," Lynch said.
Gov. Deval Patrick declared a state of emergency for the Bay State, allowing officials to make preparations.
Hoping to avoid the kind of criticism utilities received after last year's Hurricane Irene and other storms, Patrick said utilities plan to pair tree removal and power restoration crews -- rather than having them work separately -- so that work can be done more efficiently.
The City of Boston announced that schools will be closed Monday.
President Barack Obama declared a state of emergency in Massachusetts on Sunday.
Like other states in the Northeast, Rhode Island is monitoring Hurricane Sandy -- and declared a state of emergency Sunday.
The Rhode Island Emergency Management Agency is urging all residents to be prepared for prolonged power outages and wind and water damage by having an emergency kit, securing their property, and taking boats out of the water.
State authorities have been taking preparatory measures, such as checking and clearing drains in flood-prone areas and relocating needed state equipment if necessary.
Public schools in Providence, the state capital, will be closed Monday.
Bus service in Connecticut will halt at midnight and stay closed for the duration of the storm, Gov. Dan Malloy announced Sunday.
With a state of emergency declared, Malloy said his state would have 400 National Guard troops ready to assist with recovery efforts, as needed.
"Folks, this could be bad -- really bad," Malloy said, noting that forecasters are predicting 36 hours of sustained winds. "It could impact us in several ways and for a long period of time. Please take this as seriously as we are taking it."
New York's Metropolitan Transportation Authority started shutting down subway service at 7 p.m. Sunday. Bus service was scheduled to stop at 9 p.m.
Gov. Andrew Cuomo's official Twitter account announced that he directed Army and Air National Guard members to mobilize for Sandy.
The city expects a slow surge of water to flood low-lying areas such as Queens, the Bronx and Battery Park in Manhattan, Mayor Michael Bloomberg said. There are mandatory evacuation orders for some parts of New York City. Evacuation centers have been opened in 76 locations, and schools in the city are closed Monday.
The governor dispatched extra ambulances to the county to help frail and ill residents.
State authorities are taking several other preparatory steps, including bringing down water levels along the Erie Canal, Cuomo said. Airlines are trying to prevent travel chaos by allowing passengers to alter their plans, fee-free, at major airports such as LaGuardia and Kennedy.
The Port Authority of New York and New Jersey said all its trains and stations will close at midnight until further notice due to Hurricane Sandy. All Port Authority Bus Terminal carriers will suspend service by early Monday morning.
Citing the suspension of public transportation, The Broadway League canceled all Broadway performances Sunday and Monday night.
Offices at United Nations headquarters in Manhattan also will be closed Monday, as will the physical trading floor of the New York Stock Exchange. Operations will continue on the company's electronic exchange.
President Obama declared a state of emergency in New York on Sunday.
New Jersey, which has declared a state of emergency, was the first to announce mandatory evacuations. The state's barrier islands from Sandy Hook south to Cape May must be cleared out, along with Atlantic City's casinos.
"We have to prepare for the worst here," Gov. Chris Christie said. Tolls have been suspended on the northbound Garden State Parkway and the westbound Atlantic City Expressway so people in those areas can leave more quickly, he said.
All state offices will be closed on Monday, with only essential employees expected to report to work, Christie announced.
New Jersey Transit will be shutting down its entire system of trains, light rail and buses between 4 p.m. Sunday and 2 a.m. Monday, the governor announced via Twitter.
Gov. Tom Corbett declared a statewide disaster emergency ahead of the storm, which is expected to bring heavy rain to much of the state starting Sunday night, the governor's office said.
Flooding, power outages, and sustained high winds are expected, his office said. Sandy could even bring snow to some areas in southwestern Pennsylvania and in higher elevations.
"Essentially, this is a hurricane wrapped in a nor'easter," said Corbett.
Public schools in Philadelphia will be closed on Monday.
The Southeastern Pennsylvania Transportation Authority said Sunday that its service would be suspended at day's end. SEPTA, as it is known in Philadelphia, served some 770,000 riders per day last year.
Parts of the Delaware coast were already experiencing significant flooding around 5 p.m. Sunday -- hours after before Sandy came ashore -- Gov. Jack Markell said.
"We're seeing more flooding than you normally do, and particularly since the storm's not here," Markell told CNN.
Earlier, the governor declared a "limited" state of emergency, meaning it doesn't order driving bans or business closures.
Markell ordered the evacuation of all coastal communities and a flood-prone area in southern Delaware by Sunday night.
Shelters opened beginning Sunday afternoon to accommodate those who have left their homes and have nowhere else to go, Markell said.
President Obama declared a state of emergency in Maryland on Sunday.
Like several neighboring states, Maryland could see as much as a foot of rain in some areas, according to the CNN Weather Unit -- a major reason the state had already declared a state of emergency.
Officials in Ocean City ordered all downtown-area residents to leave before 8 p.m. Sunday. A voluntary evacuation order was in place for those in low-lying areas.
Besides flooding, strong winds are expected to cause significant power outages. The Baltimore Gas and Electric Company, for instance, says several hundred thousand customers could be affected, as early as Sunday.
Public schools in Baltimore, Montgomery and Prince George's County will be closed Monday.
In the coastal city of Annapolis, city crews distributed sandbags to residents and businesses to help them prepare for flooding.
DISTRICT OF COLUMBIA
The city's mass transit system, known as the Metro, will be closed Monday because of the storm.
The district is under a state of emergency, and local officials worked through the weekend to prepare residents, businesses, and infrastructure for the hurricane.
All of Washington's public schools will be closed Monday, Mayor Vincent Gray announced. "The district is preparing in earnest" for the storm's effects, which could include heavy rain, street flooding, strong winds, power outages, and storm-surge flooding along the Potomac River and its tributaries, Gray said.
The local government distributed sandbags to residents and businesses Saturday at RFK Stadium. Authorities have generators ready at major intersections in case traffic lights are knocked out, Gray's office said.
All federal buildings in the district will be closed to the public Monday.
President Obama declared a state of emergency in the District of Columbia on Sunday.
Sandbags were piled up inside restaurants in the Old Town section of Alexandria, along the banks of the Potomac River, in anticipation of Sandy's arrival.
The Virginia National Guard was authorized to bring as many as 500 personnel onto active duty.
Virginia was one of several states to declare a state of emergency ahead of the storm. Computer models predict parts of the state could see as much as a foot of rain, according to the CNN Weather Unit.
As a precaution, officials in Norfolk announced the Sunday closure of the Midtown Tunnel under the Elizabeth River, which connects the city with neighboring Portsmouth.
The storm has already forced the cancellation of rallies for both presidential campaigns. Vice President Joe Biden canceled a planned Saturday visit to Virginia Beach and Republican nominee Mitt Romney called off a planned Sunday rally in the same city.
All public schools in Fairfax County, a large school district in northern Virginia, will be closed Monday and Tuesday. Schools in Arlington, Norfolk, and Newport will be closed on Monday.
Strong winds and pelting, sometimes sideways rain lashed the Outer Banks as the stretch of barrier islands began to feel the outskirts of Hurricane Sandy.
Sandy is expected to parallel the coast before eventually making landfall somewhere in the Middle Atlantic region.
Still, even if it never passes directly over North Carolina, Sandy may still have an impact. The forecast calls for between 4 and 7 inches of rain to fall over several days in the Outer Banks, with some spots receiving 8 or more inches.
Radar showed heavy rains from the fringes of Sandy pelting much of South Carolina's coast, from Charleston to Myrtle Beach.
The Palmetto State is expected to avoid a direct hit from the storm, which is expected to eventually head over land well to the north. That said, the National Weather Service warns tropical storm conditions are possible through Sunday in Myrtle Beach, for example, before skies clear up by Monday.
CNN's George Howell, Athena Jones, Greg Botelho and Melissa Gray contributed to this report.