(Update, Sunday, noon) The National Weather Service has upgraded the forecast from a Winter Weather Advisory to a Winter Storm Warning.
The Winter Storm Warning for all of the Washington area, including Reston, is in effect until 3 a.m. Monday.
Forecasters say to expect snow, sleet and freezing rain. There may be a coating to an inch of snow that will change to sleet and freezing rain this afternoon.
There could be a one-quarter inch accumulation of ice, the NWS says.
Original story, Saturday 7 p.m.:
The National Weather Service has issued a Winter Weather Advisory for Reston and the Washington, D.C. area from early Sunday through early Monday. Expect a mix of conditions and precipitation to usher in March.
From the NWS:
WINTER WEATHER ADVISORY IN EFFECT FROM 7 AM SUNDAY TO 3 AM EST MONDAY…
THE NATIONAL WEATHER SERVICE IN BALTIMORE MD/WASHINGTON HAS ISSUED A WINTER WEATHER ADVISORY FOR SNOW… SLEET… AND FREEZING RAIN… WHICH IS IN EFFECT FROM 7 AM SUNDAY TO 3 AM EST MONDAY.
LOCATIONS… WASHINGTON METROPOLITAN AREA AND SOUTHERN MARYLAND.
HAZARD TYPES… SNOW… SLEET… AND FREEZING RAIN.
ACCUMULATIONS… A COATING TO 1 INCH OF SNOW AND SLEET ACROSS WASHINGTON DC AND SOUTHERN MARYLAND. 1 TO 3 INCHES IN THE NORTHERN AND WESTERN SUBURBS OF WASHINGTON DC. ICE ACCUMULATION AROUND ONE TENTH OF AN INCH.
TIMING… SNOW WILL BEGIN BETWEEN 7 AM AND 10 AM SUNDAY MORNING. SNOW WILL CHANGE TO SLEET AND FREEZING RAIN BETWEEN NOON AND 3 PM SUNDAY AFTERNOON. PRECIPITATION WILL END AS FREEZING RAIN SUNDAY NIGHT.
IMPACTS… ROADS WILL BE SNOW AND ICE COVERED SUNDAY AND SUNDAY NIGHT. TRAVELLING WILL BE DANGEROUS DURING THIS TIME. VISIBILITY WILL BE REDUCED BELOW ONE-MILE AT TIMES IN SNOW SUNDAY MORNING AND AFTERNOON.
WINDS… SOUTH AROUND 5 TO 10 MPH.
TEMPERATURES… RISING THROUGH THE 20S MORNING. TEMPERATURES WILL RISE INTO THE LOWER AND MIDDLE 30S SUNDAY AFTERNOON INTO SUNDAY NIGHT.
PRECAUTIONARY/PREPAREDNESS ACTIONS…A WINTER WEATHER ADVISORY MEANS THAT PERIODS OF SNOW… SLEET… OR FREEZING RAIN WILL CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR SLIPPERY ROADS AND LIMITED VISIBILITIES… AND USE CAUTION WHILE DRIVING.