The National Weather Service Baltimore MD/Washington DC issued a Winter Weather Advisory for Calvert and Charles counties, remaining in effect from midnight tonight to 10 AM EST Sunday, December 14, 2025.
Snow is expected across the two counties, with total accumulations of 1 to 3 inches forecast. Precipitation may begin briefly as rain in some areas before changing over to snow. A narrow band of heavier snow could form between 2 AM and 6 AM, leading to quicker accumulations and reduced visibility to less than one half mile in affected spots.
The advisory highlights slippery road conditions as the primary impact. Drivers in Southern Maryland should anticipate challenges on untreated or secondary roads, particularly during overnight and early morning hours when temperatures drop and snow sticks more readily.
Precautionary actions recommended include slowing down and using caution while traveling. Motorists can obtain the latest road conditions by calling 511, which provides real-time updates from the Maryland Department of Transportation State Highway Administration on state-maintained routes.
A separate Hazardous Weather Outlook issued at 1050 AM EST on December 13 covers a broader area, including the Chesapeake Bay waters, Tidal Potomac River, and I-95 corridor through central Maryland and northern Virginia. It notes the Winter Weather Advisory for the greater Washington and Baltimore areas starting late tonight and continuing through Sunday morning.
The outlook also mentions a Gale Warning for all bay and tidal waters from Sunday morning into Sunday evening, extending overnight for the lower Potomac and middle Chesapeake Bay. Cold wind chills approaching 0 degrees are possible late Sunday night into early Monday morning.
The Maryland Department of Transportation State Highway Administration maintains primary routes in these counties and deploys equipment for pre-treatment and plowing when advisories are issued. Calling 511 connects callers to live updates on traffic incidents, closures, and weather-related delays specific to Maryland highways.
Winter Weather Advisories are issued when snow, sleet, or blowing snow is expected to cause significant inconveniences and potentially hazardous travel, though not rising to warning criteria.
Broader regional forecasts align with this event as a quick-moving system bringing light to moderate snow overnight Saturday into Sunday. No spotter activation means conditions are not anticipated to require widespread public reports, though trained weather spotters may submit observations voluntarily.
Preparation steps align with standard winter guidance for the area: ensure vehicles have adequate windshield washer fluid rated for freezing temperatures, maintain at least half a tank of gas, and carry emergency supplies like blankets and flashlights. Clearing sidewalks and driveways after snowfall helps prevent refreezing issues common in Southern Maryland’s fluctuating temperatures.