The National Weather Service (NWS) expects Tuesday morning’s wintry precipitation to start between 5am and 7am for most of the area, according to its “Winter Precip Onset Times” map.
The Winter Weather Advisory goes into effect at at 3am on Tuesday and lasts until 1pm. The heavy rain is expected to changeover to snow between 5am and 7am, with the NWS projecting 1-2 inches of snow for most of the county and more snow possible further north (NWS maps below).
Loudoun County in Virginia (MoCo’s neighbor to the west) has already made the decision to close schools, while Carroll County in MD and Fairfax County in VA have already announced delays for Tuesday. Frederick County has communicated that they’ll be watching the weather, but that there isn’t yet enough information to make a decision on schools. Our prediction can be seen here.
With temperatures expected to be above freezing, the snow will have trouble sticking unless it falls hard enough to overcome the warm ground. If it falls at a heavy rate, then conditions can get pretty slick. The timing of the wintry precipitation is likely to cause headaches for many school systems trying to make the best decision in the morning. Expected Snowfall, Reasonable Worst Case Scenario, and Low End maps available below.
