7:25 a.m. Update: We’ve heard that flakes have started to fall out west near Warrenton, Va., in Fauquier County and along the I-81 Corridor, while radar shows snow to the south, slowly edging north into Fredericksburg. Pretty much right on target with our expectation of snow developing generally from south to north between approximately 7-11 a.m. It may take over the next couple hours in the immediate metro area for the dry air to saturate and snow to begin. Importantly, it is cold everywhere with temperatures mostly in the upper 20s to near 30.
From 4 a.m. …
FORECAST IN DETAIL
The winter storm we’ve been tracking all week arrives today with a variety of precipitation types and varying impacts depending on location. Most should start with some morning snow, then changing over to sleet and freezing rain this afternoon and mainly freezing rain tonight. Driving could be hazardous at times, especially as ice builds up this afternoon into tonight, and some power outages are possible mainly tonight. While impacts may be fairly significant in the metro area, far western areas could be in for a serious ice storm.
We warm up enough tomorrow for plain old rain to help wash away the icy mess. But we’re not out of the wintery woods quiet yet, as Tuesday brings another threat for accumulating snow.
Today (Sunday): If you’ve got anything to do today, the earlier the better. Snow develops, generally from south to north, by mid-morning and could accumulate 0.5-2″ in the metro area by early-to-mid afternoon. Treated roads should be manageable through the morning, but could get slick if there are any heavier bursts of snow, which could also lower visibilities. Things then start to get more messy as snow likely switches over to sleet and freezing rain from southeast to northwest during the afternoon. By late afternoon and evening, treated roads may still be passable but you’ll want to drive with care, while untreated roads, ramps, bridges and overpasses could be dangerously icy. Temperatures don’t do much during the day hovering in the upper 20s to near 30. Winds are generally light from the north-northeast at around 5-10 mph. Confidence: Medium-High
Tonight: Sleet and freezing rain should become primarily freezing rain during the evening and continue into the overnight with temperatures steady in the upper 20s to low 30s. Some power outages are possible in the metro area during the night as ice weighs down trees and power lines, but the biggest risk of more numerous power outages is in the far western suburbs and points west (purple part of ice forecast map below). Overnight, slightly warmer air slowly moves in from the southeast. The timing is far from certain, but areas from around I-95 and the District toward points east should change to plain rain during the overnight hours, while areas west of there may have to wait until approximately 5-8 a.m. for temperatures to rise past freezing. Confidence: Medium
For related traffic news, check out Dr. Gridlock. Keep reading for the forecast for another shot of winter toward midweek…
Tomorrow (Monday): The storm isn’t over as we head into tomorrow, but for the most part, the winter side of it is. Winds from the south push warmer air in at the surface and any remaining freezing rain west of I-95 and the District should see a changeover to rain by mid-to-late morning. Intermittent showers continue through the morning and probably into the afternoon, helping to melt all but the heaviest of ice accumulations. Highs range from the upper 30s (NW) to low 40s (SE). Confidence: Medium-High
Tomorrow night: We finally see a little break in the action Monday night, though some light showers and drizzle are still possible, especially to the south and east. Winds switch back to come from the northwest, bringing colder air back in and setting the stage for another tricky storm system. Otherwise it’s a mostly cloudy night, with lows in the upper 20s to low 30s. Confidence: Medium-High
A LOOK AHEAD
Another disturbance forming along a nearby cold front could bring more wintry weather as soon as early Tuesday morning. This time though, it’s more of a snow or rain question, with much less of an icing threat. It’s also a question of how much precipitation the system will produce, and whether it will pass over the D.C. area or skip by to the south. To be honest, models are currently not in close agreement on this system and we don’t have a good handle on it yet. We hope to have a better idea by this evening and early tomorrow. Highs range from only the low-to-mid 30s if it snows, to near 40 if it doesn’t. Tuesday night lows reach down into the 20s to near 30. Confidence: Low
Whatever happens Tuesday, on Wednesday we finally break out of our stormy streak. High pressure takes control and gives us a bright but chilly day. Expect mostly sunny skies and highs in the mid-30s to near 40. Confidence: Medium-High
Dan Stillman contributed to this forecast.