The governor and mayor of Philadelphia both declared states of emergency, the School District of Philadelphia canceled classes for Monday and the University of Pennsylvania and several other local universities canceled classes for Monday and Tuesday. Even Halloween parades were canceled.
The storm was expected to result from Hurricane Sandy coming ashore late Monday or early Tuesday, most likely in New Jersey, and colliding with a wintry storm moving in from the west and cold air streaming down from the Arctic. Forecasters warned that the resulting megastorm could wreak havoc over 800 miles from the East Coast to the Great Lakes.
Philadelphia's transit authority said it would shut down subways, commuter rail, buses and trolleys at about 12:30 a.m. Monday, and officials expected service to remain suspended at least through Monday. The American Red Cross opened evacuation centers in the area, and Philadelphia residents bought water, food and other supplies Sunday to ride out the storm.
At The Fresh Grocer in west Philadelphia, Tayna Lindsey, 38, was among those stocking up. She bought nearly $200 worth of food, including a turkey, and planned to cook as long as her power was on.
"If my kids are home," she said, "they need to eat. I have a big family."
She intended to prepare plenty of food for her husband, four children, a grandchild, other relatives and neighbors and to take some with her to work as a medical assistant at the University of Pennsylvania hospital.
Wade Green, 24, of Philadelphia was leaving the store with a case of water and other supplies. But the new city sanitation employee said he has raingear ready and has been told that he might be working during the storm.
"I already know I'm going to be in the middle of it, so I'll be preparing for it," he said. "Prepare for the worst, hope for the best."
At a marina in Philadelphia's Penn's Landing section on the Delaware River, where about 20 people live on houseboats, people were helping each other secure lines but felt the floating dock and the condominiums on either side of the marina would help protect their vessels.
"We're going to be as safe here as we would be anywhere because we're going to be as high as the water gets, plus we've done the prep work," said 62-year-old Howard Molt.
Across the way, Hans Eriksson, 35, who lives on a houseboat with his wife and 19-month-old daughter, said they had spent 2½ years sailing in the Caribbean so they feel they will be all right.
"If it starts looking dangerous, obviously we'll get off the boat," said Eriksson.
Peco Energy, the commonwealth's largest electric and gas utility, said Sunday it has 300 electric line crews and 150 tree-trimming crews from as far away as Illinois and Mississippi ready to go.
"This is definitely what we call an all-hands-on-deck effort," Peco spokeswoman Karen Muldoon Geus said.
Muldoon Geus said she expects some customers to be without electricity for multiple days, and shutting down power to certain areas is likely in areas with heavy flooding.
The utility will also have trailers with response crews in flood-prone areas to quickly turn off gas service where necessary.
In portions of western Pennsylvania, the National Weather Service issued a flash flood watch for areas that could get more than two inches of rain Monday and Tuesday, causing some flooding along small streams or where drainage is poor. Officials said larger rivers may be affected if the heavy rain is widespread. A high wind watch was issued for winds expected to reach 25-35 mph with gusts of 50-60 mph, and snow was expected later in the week.
The Pennsylvania National Guard has told about 16,000 members to be ready to deploy for a storm response if activated. In addition, the 56th Stryker Brigade combat team ended training a day early at Fort Indiantown Gap in suburban Harrisburg to return to its base at Horsham Air Guard Station in suburban Philadelphia to prepare, said spokesman Maj. Edward Shank.
The combat team alone has several dozen Stryker vehicles and several dozen heavy trucks that can respond, he said.
Communities elsewhere in Pennsylvania postponed or canceled their Halloween parades with the approach of the storm.
Parades scheduled in Allentown and Bethlehem on Sunday were postponed until Nov. 4, the Morning Call newspaper reported.
In Franklin County in central Pennsylvania, police said the 70th annual Mercersburg Halloween parade scheduled for Monday night was canceled. It was only the second time in 70 years that the parade was canceled, the Herald-Mail of Hagerstown, Md., reported.