* Winter Weather Advisory for northern Maryland (including Frederick and Carroll counties) midnight tonight to 7 p.m. Saturday *
10 p.m. update: As we said would be the case earlier, precipitation this evening has been spotty with mainly patchy light rain. Towards Frederick and western Loudoun counties, we’ve seen a mix of rain and snow or just snow, especially in the higher terrain, but with little accumulation. Radar is currently filling in a bit west of D.C., so precipitation should increase in coverage a bit and work east. And as the night wears on, the rain/snow line should gradually get closer to the city. Precipitation amounts should generally be light and there’s no reason to change our snow map below, which indicates little or no overnight snow accumulation until you get well west and north of D.C.
From 5 p.m.: It was the 19th straight milder than average day, but clouds moved in quickly this afternoon, capping temperatures a few degrees shy of expectations (in the mid-to-upper 40s). Areas of light rain arrive this evening, mixing with and changing to sleet and snow late tonight mainly in the outer north and west suburbs. Saturday’s blustery with falling temperatures late along with possible snow squalls after dark. Sunday’s windy and quite cold, but probably precipitation-free.
Through Tonight: Spotty rain showers (mixing with snow well north and west) this evening become a bit more numerous after midnight. As the night wears on, rain may mix with and change to sleet and snow, particularly in Loudoun and Frederick counties. A light snow accumulation of an inch or less is possible in those areas, particularly in higher terrain. Closer to the beltway, the rain may end as brief period of snow or a wintry mix with no accumulation. Low temperatures range from near freezing in Loudoun and Frederick county to 35 downtown.
Saturday: Widely scattered rain and/or snow showers are possible intermixed with intervals of sunshine through the afternoon. No day time snow accumulation is likely. Temperatures may warm up to about 40 by early-to-mid afternoon before beginning to fall off. It progressively becomes more windy, with afternoon winds from the north at 15-20 mph with higher gusts.
Saturday night: It turns sharply colder and windy with a 50-60% chance of snow showers. Snow showers will be hit or miss but they may contain brief, heavy bursts. A dusting or so is possible. With temperatures falling rapidly below freezing, slick spots could develop. By midnight temperatures are in the mid-to-upper 20s. Snow shower activity should diminish after midnight, with morning lows from the upper teens to low 20s (suburbs-city). Winds are from the north at 20-30 mph, with very strong gusts to 35-40 mph. Wind chills reach the single digits in some spots by Sunday morning.
Sunday: One of the coldest days of the winter thus far. Although skies are partly to mostly sunny, the Arctic air mass makes it a struggle to rise above freezing. Highs range from 29-34 (colder suburbs to downtown and south and east). Winds are from the northwest at 15-25 mph, with gusts to 30 mph. Wind chills will frequently be in the teens.