With the second blizzard of the season blasting into the region today, officials say they are ready to tackle the foot or more of snow expected to blanket Philadelphia and surrounding counties.

Some schools are planning early dismissals today. Airlines have canceled flights scheduled for this afternoon and tonight. And officials in Pennsylvania and New Jersey said they had already treated key roads with a brine solution to prevent snow from sticking.

"The good news is, we've been here before," said Mayor Nutter's spokesman, Doug Oliver, referring to December's historic storm. "We're prepared."

"We've gotten a lot of notice on this," said Pennsylvania Department of Transportation spokesman Charles Metzger.

The National Weather Service was so confident that it issued winter-storm and blizzard warnings right after lunch yesterday, more than a good day before the first flakes were anticipated.

"We're pretty certain that it's coming," said Andrew Ulrich, a meteorologist with AccuWeather Inc. in State College, Pa.

The storm is expected to come into its own in the region tonight, with heavy snow continuing through tomorrow morning.

Bart Leff, Camden schools spokesman, said students would be dismissed at 1 p.m. in anticipation of the snowstorm.

"We're attempting to be proactive with the safety and security of our kids," Leff said.

Philadelphia public school officials yesterday had not yet made a decision on whether to dismiss school early. Spokesman Fernando Gallard said the district would continue monitoring weather reports before coming to a conclusion.

Oliver said Philadelphia had 34,000 tons of salt available, and planned to deploy 600 workers and 340 pieces of equipment at the height of the storm.

"We'll do everything we can to have the streets prepared for businesses and for Philadelphians as soon as reasonably possible," Oliver said.

Metzger said PennDot had 92,600 tons of salt and 420 trucks available for the five-county Southeastern Pennsylvania region.

On its Web site yesterday, Southwest Airlines announced that it had canceled the majority of its flights for later today and all flights tomorrow for the Philadelphia, Baltimore and Washington Dulles airports.

Morgan Durrant, spokesman for US Airways in Philadelphia, said the airline, which has 400 daily flights out of Philadelphia International Airport, had canceled 50 mainline flights and 165 Express flights systemwide out of 3,000 flights.

US Airways and several other airlines said passengers could reschedule flights scheduled through Sunday in the mid-Atlantic region without a penalty or charge.

Airport officials urged travelers and anyone planning to pick up people at the airport to contact their airline; the airport's toll-free flight information line at 800-PHL-GATE; or the airport Web site at www.phl.org to check the status of their flights.

"Usually, I roll my eyes because the forecast is usually only six inches and people get hysterical about buying milk and bread," said Joe Orlando, spokesman for the New Jersey Turnpike Authority.

"Finally, there's a storm that's worthy of concern," he said.

And he was right, about the people. Reports from the region last night were that the supermarkets and stores were very busy.

As one shopper at a Whole Foods store in Center City put it: "I came in for chicken, and this place is packed. It's like the masses are stocking up for World War III."

With an unusual unanimity, computer models and the humans who use them are expecting a foot of snow generally across the area - or perhaps more.

Blizzard warnings were in effect for New Jersey's coastal counties, where winds could gust past 45 m.p.h., and for central and southern Delaware.

The bull's-eye appeared affixed to the Baltimore-Washington area, where up to two feet was possible, but the storm track could nudge a tad farther north, meteorologists said.

Philadelphia's snowfall this season is 140 percent of normal, and by the time the storm shuts off tomorrow, the winter of 2009-10 could become one of the 10 snowiest on record.

The National Weather Service said yesterday that the approaching storm bore a rather menacing resemblance to that of Dec. 19-20, which left close to two feet in Philadelphia. That one took a northward jog at the last minute.

There's an outside shot that storm would come so far north that it would draw in warm air to cause mixing and hold down snow totals, or pass unexpectedly to the south. But those scenarios were highly unlikely, said Lee Robertson, a weather service meteorologist in the Mount Holly office.

The government's Hydrometeorological Prediction Center, outside Washington, warned that the storm would wring out an "incredible amount" of moisture as it migrated across the South and redeveloped off the North Carolina coast.

Snow totals would depend to a degree on the snow-to-liquid ratios. An inch of water could yield from 10 to 15 inches of snow, depending on the temperature profile of the atmosphere.

An additional foot this weekend would push the seasonal total to near 40 inches, making a run at the winter of 1916-17, No. 10 on the all-time list at 39.6.

What's going on?

Storms riding the strong upper-air winds associated with El Niño, the unusual warming of surface waters in the Equatorial Pacific, have been able to mine copious moisture from the Gulf of Mexico.

By the way, snow is possible again Tuesday.