* Winter Weather Advisory N&W of D.C. from 6 p.m. this evening through 11 a.m. Wed. morning (includes Montgomery, Loudoun & Frederick counties) *
Cold air continues to bleed southward due to an area of cold high pressure building in from the north. At the same time, one wave of light rain after another is moving from west to east along a stalled front to the south. The combination of falling temperatures and waves of precipitation may cause the light rain to gradually change to a wintry mix this afternoon and evening in the north and west suburbs, with a little sleet possibly mixing in inside the Beltway (especially after dark).
Here's our current thinking:
Far north and west suburbs (Loudoun and Frederick counties and to the north and west): Temperatures will likely fall to near freezing from northwest to southeast between 4 and 8 p.m. this evening. A mix of rain and sleet is likely during the afternoon, probably changing to a frozen mix of sleet and freezing rain tonight. A little snow is also not out of the question -- especially toward the north (heading toward the Pa. border). Some icy roads are possible, especially after dark this evening. The precipitation should change back to rain by mid-morning Wednesday as temperatures warm again.
Close-in north and west suburbs (Fairfax and Montgomery counties): Light rain may mix with or change to sleet this afternoon, with heavier precipitation (including the chance of some patchy areas of freezing rain in the normally colder spots such as Oakton and Gaithersburg) possible later in the evening and overnight. Temperatures may (50% chance) fall to right around the freezing mark between 6 p.m. and midnight, primarily outside the Beltway and mainly west of I-270 and north of I-66. If they do, then a few slick spots could develop, especially on ramps, bridges and overpasses.
Downtown and south and east suburbs (including south of I-66 in Va.): Rain could become heavier and mix with sleet this evening and overnight. But with temperatures mostly just above freezing, we don't foresee travel problems beyond those that would be caused by plain rain.
Stay tuned for updates as conditions warrant.