It was a week that the Washington region would have preferred to end with a deep sigh of relief over terrorist threats still unrealized.

Instead, forecasts for sleet, snow and freezing rain last night launched a new wave of shoppers into supermarkets and home improvement stores, and cancelled all sorts of events.

No weekend school activities were to be held in Montgomery, Prince George's, Calvert, Charles and Anne Arundel counties in Maryland, Prince William County in Virginia or the District. The Dulles District volleyball tournament, scheduled for today, was rescheduled for Monday.

Loudoun County public schools canceled some athletic activities because of the forecasts, though Fairfax school officials said they would wait to make a call.

Light snow began falling late last night at Reagan National Airport, and according to forecasts, those flakes might have been only the first of a weekend that would bring a foot or more to parts of the metropolitan area.

Earlier in the week, with the federal government's terrorist threat alert raised to Code Orange, consumers stocked up on stuff to seal homes and offices against gas or germs. Yesterday, they jammed roads and parking lots, clearing supermarket shelves of milk, bread and other perishables, in fear of being trapped by the weather.

Was it busy at the Braddock Road Safeway in Fairfax County last night?

"Oh, you're joking, right?" said front end manager Scott Fair. "How about I have no more milk in my case? We're getting the triple-duty thing: We've got the terrorists, we've got Valentine's Day and we've got the snow."

Gallons of water were cleared off shelves. Distributors made extra deliveries of Coca-Cola, Pepsi, Aquafina and Dasani.

"All of our cash registers have been open the last eight hours," Fair said. "This store has been here 30 years and we've already exceeded our best day ever."

Business was brisk at the Mills liquor store in downtown Annapolis. "There's always a little panic buying if they think they're going to be snowed in for a week," said wine consultant John Chadwick. "If you don't have enough in your house to get through two days, that's pretty sad."

Staff writers Rosalind S. Helderman, Nelson Hernandez, Martin Weil, John F. Kelly, Theola Labbe, Justin Blum, Mitra Kalita and Elaine Rivera contributed to this report.

With snow forecast, Akila Young, 10, top, and sister Tiye, 5, of Varnum Street NE may have another chance to make snow angels this weekend.