* Winter weather advisory from 6 a.m. to 3 p.m. Tuesday (except Calvert and St. Mary’s counties) *
10:40 p.m. update: This evening’s model runs suggest an enhanced area of snow tomorrow just north and west of D.C. In our updated map below we’ve bumped those areas up to 1-3″ with most everyone else still in the 0.5-1.5″ range. Most of the snow falls between approximately 8 a.m. and 6 p.m., and much of the accumulation may end up on grassy areas rather than roads. But even the pavement could be briefly coated at times, especially during any heavier bursts and especially in the 1-3″ area.
Today’s temperatures were about normal for the coldest part of the year. D.C. snuck past 40 degrees, but many locations were stuck in the 30s. After a record low this morning, Dulles should also tack on a record low maximum today as long as it stays under 40 degrees there. Sick of winter? You may want to stop reading, and hide indoors for the next day or two.
Through Tonight: We start the night fairly clear, with just some high thin clouds around. Especially once we get toward and after midnight, those clouds should begin to thicken and lower. Light snow may begin to move into the area in the hours before sunrise, and becomes more likely as the sun comes up. Anything that falls in this period may briefly cause slushy roads if it’s intense enough, but most accumulation should be quite light and on grassy surfaces. Lows make the upper 20s to near freezing.
Tomorrow (Tuesday): Mainly light snow — with periods of moderate or even heavy activity — becomes likely after sunrise. The most consistent activity should try to center on the midday, possibly continuing through the afternoon, and tending to wane west to east late in the day. With temperatures rising to and past freezing in the 8 to 11 a.m. time frame east to west, snow accumulation should be largely confined to grassy and elevated surfaces. Highs ultimately make the mid-to-upper 30s most spots. In general, 0.5-1.5 inches is the most likely range of accumulation, again focused on grass. A trace to 1 inch is expected in our far southeast towns. Winds pick up by late in the day as well, eventually gusting past 30 mph from the north and northwest.
Tuesday targets: March 25 is D.C.’s last day with a “normal” snow total until next winter, and it’s a whopping 0.1 inch. The record snowfall for the date is 1.5 inches set in 1906. The record low maximum of 33 degrees and record low of 19 degrees both appear safe despite the fact that we’ll be running a good 20-25 degrees below normal. Out at Dulles, the record snowfall for the date is 3.2 inches, set just last year. Since the historical period there is much shorter than D.C.’s getting records is considerably easier. And the record low maximum of 38 degrees set in 1974 may fall tomorrow. The record low for the date of 17 degrees should hold.