Schools closed, salt trucks ready. But no snow in sight, and temperatures above freezing Washington braced for heavy snow on Tuesday, with four to seven inches of accumulation expected through much of the area, and the worst of the storm predicted to hit around midday. The region had gone into its usual shut-down mode overnight based on the forecasted accumulation, with schools , the federal government and many local governments closed. Temperatures were falling throughout the morning and were below freezing north of the District by 9:45 a.m. Forecasters expect a big winter storm to drop up to 10 inches of snow from Virginia to New England on Tuesday. National Weather Service Washington Post staff Which schools, offices and governments have closed or delayed because of the weather? Get updates on the winter storm and find the latest forecast for the Washington region. The Washington Post's Capital Weather Gang said the snow was falling in Bethesda, Takoma Park and Vienna by 9:30, and should appear in most parts of the area by 10 a.m., continuing into evening. Road temperatures will likely remain a bit above freezing for a residual period, which means that at first the snow that falls on the asphalt in some areas could melt, rather than stick. Meteorologists had said late Monday that between five and 10 inches of snow was expected. But by 6:25 a.m. Tuesday, the Capital Weather Gang had revised those totals to between four and seven inches. Forecasters said the expected snowfall, and increasing winds and cold temperatures, would probably mean difficult road conditions for the afternoon commute. Road crews in the area had begun mobilizing late Monday and were out Tuesday morning pretreating roads. "Today will be very challenging for highway workers and travelers with the snow falling along with temperatures and expected high winds," said Maryland State Highway Administrator Melinda B. Peters. The northeastern part of the United States, including Philadelphia, New York and Boston, are expected to get more than 10 inches of snow, prompting the cancellation of thousands of flights in the busy corridor. On Tuesday morning, 55 flights were canceled at Baltimore-Washington International Marshall Airport, 92 were canceled at Dulles International Airport and 130 were canceled at Reagan National Airport, according to FlightAware. Metro was operating on schedule Tuesday morning but canceled its door-to-door bus service for those with disabilities. The transit agency warned that it might reduce service levels later in the day because of anticipated "low ridership and deteriorating weather conditions." Metro's buses could experience delays or take detours. The transit agency said it will send out a three hour notice to its riders before it suspends service if that becomes necessary. MARC and VRE trains were operating on abbreviated schedules because of the anticipated weather. A special election to fill a vacant seat in the 33rd Virginia Senate District was still taking place Tuesday, Fairfax and Loudoun counties said on their Web sites. Elections officials were urging voters to cast ballots early, before the weather becomes a problem.