Hurricane Sandy is churning off the East Coast and is expected to join up with two other weather systems to create a huge and problematic storm affecting 50 million people. Here’s a snapshot of what is happening or expected, state by state.

CAROLINAS

The storm lashed barrier islands off North Carolina and rendered several homes and businesses nearly inaccessible. About 90 miles off the coast, a tall ship carrying 17 people was in distress; the Coast Guard was monitoring.

CONNECTICUT

The number of power outages increased quickly in a state where utilities’ response to past weather-related failures has become a political issue. Connecticut Light & Power says hundreds of customers are without power. Gov. Dannel P. Malloy asked a task force to ensure fuel suppliers are fully stocked. Many residents along Long Island Sound heeded warnings and evacuated.

DELAWARE

Hundreds of people fled to shelters as rough surf pounded the coast. Water covered some roads.

KENTUCKY

Snow is expected in mountainous areas.

MAINE

Officials predict coastal flooding and beach erosion, and utility crews have been brought in from Canada to handle anticipated power failures.

MARYLAND

Hurricane Sandy inflicted considerable damage overnight to a large, iconic ocean pier in the Maryland beach resort of Ocean City. In mountainous western Maryland, a blizzard warning was issued for sections of Garrett County for Monday night into Tuesday morning.

MASSACHUSETTS

Utilities brought in crews from as far away as Texas and the Midwest to cope with anticipated power failures. Most schools and colleges have canceled classes. The Boston transit authority said it would continue to operate as long it was safe.

NEW HAMPSHIRE

Gov. John Lynch put 100 National Guard soldiers on active duty to help with preparations. Two shelters are being set up, and some schools have closed.

NEW JERSEY

Much stronger winds, rain and flooding marked the approach Monday of Hurricane Sandy, on its way to a predicted direct hit on New Jersey. Tidal waters crossed the main oceanfront drive in the south end of Cape May, and streets near the Atlantic City Boardwalk began to flood. Officials closed a section of the Garden State Parkway because of flooding.

NEW YORK

Many residents left low-lying flood evacuation zones, and the subway system shut down Sunday night. A storm surge of 11 feet is possible, the highest of all coastal areas being hit by Sandy. The New York Stock Exchange and other U.S. financial markets shut down for at least the day. Thousands of flights were canceled at the city’s major airports.

OHIO

Residents of low-lying areas and along Lake Erie were told to watch for flooding; utilities are anticipating high winds that could blow down trees and poles. Snow is forecast in some areas.

PENNSYLVANIA

Many schools closed. Philadelphia shut down its mass transit system, and hundreds of flights were canceled at the city’s airport. Dozens of people took shelter at evacuation centers. Thousands of members of the National Guard have been told to be ready for deployment.

RHODE ISLAND

Officials are concerned about wind driving water north up Narragansett Bay, which could create flooding in low-lying areas of the upper bay, including Providence, Warwick and Cranston. About 2,600 National Grid customers were without power, mostly in Barrington and other parts of Bristol County.

TENNESSEE

Snow is expected in higher elevations, where a freeze warning has been issued. High winds are expected in many areas.

VERMONT

Gov. Peter Shumlin declared a state of emergency to provide access to National Guard troops in a state still recovering from the devastating effects of the remnants of Hurricane Irene. Culverts and storm drainage basins in some spots have been cleared of debris.

VIRGINIA

About 4,800 customers lacked power, and a utility said as many as 1 million could ultimately lose electricity. Many residents of Chincoteague Island, popular with tourists, shrugged off the idea of evacuation.

WASHINGTON, D.C.

The capital area’s transit system shut down rail service for the first time since 2003, and the Smithsonian Institution closed for the day.

WEST VIRGINIA

As much as 2 to 3 feet of snow was forecast in mountainous areas, and flooding was possible in some areas. At least 14 counties are under a blizzard warning Monday as high winds and heavy, wet snow moves through the state.

• Associated Press