As forecasters predicted that the season's first snowstorm could begin by late morning today and cause problems by evening rush hour, the truly cautious weren't taking chances yesterday.

At hardware stores across the region, the normal Sunday crowds looking for bargains on Christmas lights were joined by shoppers who loaded their baskets with salt and shovels and, for the fun of it, sleds. Youngsters were having visions of a snow day and construction of snowmen, snowwomen and snowchildren.

It appeared last night that only a very light snow could fall during this morning's rush hour, said National Weather Service forecaster James Brotherton. But he said the afternoon would "probably be a whole different story."

He said forecasters expected that snow could start to fall "in earnest" as early as 11 a.m. in the Washington area and that it would be accumulating by the afternoon rush. The heaviest accumulations were expected in the southern and eastern reaches of the area, including Calvert and St. Mary's counties in Maryland and Stafford and southern Prince William counties in Virginia.

By the time the storm ends tomorrow morning, Brotherton said, parts of those areas could be under as much as eight inches of snow. In the immediate Washington area, such as places within the Capital Beltway, accumulations are more likely to be in the three- to six-inch range, he said.

"We have high confidence that there is going to be a swath of accumulating snow across the region," Brotherton said. "It's a little tricky to pinpoint where."

Late last night, uncertainty about timing and amounts also remained. In a printed explanation of its forecast, the Weather Service said a sharp dividing line was expected between areas of heavy snow and areas of light snow.

AccuWeather, a private forecasting service, issued a forecast similar to that provided by the Weather Service. It called for the storm to begin around midday, with accumulations of three to six inches in the Washington area.

Yesterday's warm temperatures made it unclear how quickly the snow would begin to stick.

"The pavement was really warm today," Weather Service meteorologist Brian Guyer said. "As the day goes on, any untreated roads will be slushy."

The storm, which is coming from the southeast, is a different storm than the one that dropped two to three inches of snow in New York City and surrounding areas yesterday, said Roger Smith, another Weather Service meteorologist. The Weather Service issued a heavy-snow warning for Charlottesville, saying five to 10 inches of snow was possible.

Slush or snow could affect driving. Metro has salt and additional employees ready, said Candace Smith, a Metro spokeswoman. If there is less than two inches of accumulation, bus and train riders should expect normal service, but there could be delays if snow builds up, she said.

The prediction of snow was enough of a threat to send people to stores to stock up on the necessary provisions.

At Strosniders Hardware Store in downtown Silver Spring, garden manager David Dayhoss spent Saturday and yesterday clearing out a display of yard tools to make way for dozens of brightly colored snow shovels. There were compact models with extendable handles ideal for storing in a car's trunk and oversize steel shovels with curved handles designed to make shoveling easier on the back. Outside, there were big bags of sand called "Winter Traction Grit" and a colorful display of sleds ranging from the super flimsy Flying Carpet for $3.99 to the Lightning Foam, which cost $42.99.

The sun was shining and the air felt mild, but employee John Brehm said he'd seen several customers stocking up on salt and shovels. "One guy just left here carrying six containers" of snow-melting materials, he said. "I told him to put it back."

But there was no stopping those with a true passion for preparation.

"I had forgotten what makes an effective shovel," said Greg Thomas of Silver Spring, who with his wife and two young daughters recently returned to the United States after four years in Thailand.

It never snowed there, said his wife, Erica, a foreign service officer. When school was canceled because of typhoons, she said, "they called them typhoon days."

Natasha, 8, and Rhiannon, 6, could hardly contain their excitement about the possibility of playing in a sea of white. "They've been talking about the snowman and what it's going to look like," Greg Thomas said.

But he was more focused on getting the right shovel and snow-melting compound.

At Home Depot in Waldorf, people were shopping for big-ticket items even before noon, said Charles Gilbert, assistant store manager of operations. "We've sold about four or five of the snow throwers," he said. "They range from $99 to $800. It depends on the horsepower you want to get."

The Trail Blazer Snow Auger shovel also was selling briskly at $34.99. "That's for people who can't do the snow shoveling. It pushes it to the side," Gilbert said.

And what does an expert, such as Gilbert, use? "I have a shovel and a lot of brother-in-laws. We're going to be all right. I don't have the snow thrower mentality yet," he said.

Staff writer Martin Weil contributed to this report.