FORECAST IN DETAIL
The week starts off innocently enough, with some gentle morning rain and a mild afternoon. Then Tuesday is tranquil. But Wednesday into Thursday, Arctic air blasts into the region and we can’t rule out some snow showers as it arrives. The combination of wind and cold on Thursday is the most brutal of the season so far. When the next storm system moves in Friday night into Saturday, we may have snow and mixed precipitation before it likely turns over to rain.
Today (Monday): Light rain is likely this morning which should taper off midday. In some of our colder areas in western Loudoun and Frederick counties, look out for pockets of freezing rain — mainly before sunrise. Total rainfall should vary between about 0.1 to 0.5 inches. As skies brighten in the afternoon, temperatures rebound and should max out within a few degrees of 50. Confidence: Medium-High
Tonight: Partly cloudy skies and seasonably cold air. Lows range from near 30 in our colder areas to the mid-to-upper 30s downtown. Confidence: Medium-High
Tomorrow (Tuesday): This wins the prize for the week’s nicest day, although it’s nothing special. Under a mix of clouds and sun, highs climb up to near 50 — which is close to normal for this date. Breezes are light from the southwest. Confidence: Medium-High
Tomorrow night: High clouds begin to slowly increase ahead of the Arctic front — but no precipitation is expected. Lows range from near 30 in our colder areas to the mid-30s downtown. Confidence: Medium-High
A LOOK AHEAD
The Arctic front noses into the region Wednesday, but the balance of the day’s weather is calm. Highs settle in the mid-40s during the afternoon, with more clouds than sun. At night, as the front finally pushes through, winds increase and the cold air begins rushing into the region. We can’t rule out (20 to 30 percent chance, highest northwest of the Beltway) some scattered snow showers (little or no accumulation) as lows dip into the 20s in the area. Confidence: Medium
Thursday brings a punishing combination of wind and cold. Temperatures more or less hold steady in the 20s to near-30 degrees, while winds are sustained at 15 to 25 mph, with some higher gusts. Wind chills are in the teens much of the day and we can’t rule out a flurry as clouds whisk by from the northwest. Thursday night is very cold and winds only slowly relent. Lows range through the teens (to near 20 downtown) and wind chills are in the single digits. Confidence: Medium
The wind will have settled down by Friday, but it’s still quite cold. Despite plenty of sunshine, highs are only 30 to 35. Confidence: Medium
The forecast for Friday night and Saturday is complicated. Low pressure approaches from the west and, if precipitation breaks out at night, it is likely to start as snow or mixed precipitation. But if the precipitation waits to start until during the day Saturday, milder air may have arrived meaning any period of frozen precipitation would probably be short before a transition to rain. It’s still too soon to really pin down how much frozen precipitation to expect and the duration. Lows Friday night are in the 20s before highs Saturday may climb to near 40. Confidence: Low-Medium
Rain is likely Saturday night with temperatures near 40. The rain could linger into Sunday before the next surge of Arctic air arrives (timing is uncertain — it could be during the day Sunday or at night) with windy conditions and temperatures steady or slowly falling into the 30s. Confidence: Low-Medium
SNOW POTENTIAL INDEX
A daily assessment of the potential for at least one inch of snow in the next week, on a 0-10 scale.
1/10 (→): Any snow showers late Wednesday unlikely to amount to much. Any weekend wintry mix probably not a big snow producer.