PM Update: Chance of rain, sleet, light snow tonight mainly south of D.C.

Temperatures have remained steady or slowly fallen today, as a colder airmass oozes into the region. At the same time, a weak wave of low pressure is approaching from the southwest. This combination of cold air and moisture produces a chance of a little light rain and/or snow tonight, mainly in southern Md. and northern neck of Va. The rest of the weekend is mainly dry and chilly.

Through Tonight: In D.C.’s northern suburbs, there’s less than a 20% chance of light rain and/or snow. These chances increase to 50% in Prince William and southern Prince George’s county. The most likely timing is between 7 p.m. and 3 a.m. With temperatures above freezing (34-40) and precipitation generally light, no accumulation is expected.

South of Prince George’s and Prince William counties, the chance of precipitation increases to better than even and begins as early as between 4 and 5 p.m. in the southwest (towards Stafford and southern Fauquier counties). Rain, perhaps mixed with sleet, is most likely initially. Precipitation may mix with and change to sleet and snow before ending. Accumulation is unlikely.

Gradual clearing occurs late at night, with early morning lows 30-35 (suburbs-city).

The weekend: Saturday is mostly sunny and chilly, with highs 40-45. Winds are from the north around 10 mph. Increasing clouds Saturday night with a 20-30% chance of snow flurries. Lows from the upper 20s to low 30s (suburbs to city). Becoming partly sunny Sunday, with highs in the low-to-mid 40s.

See Camden Walker’s forecast through the weekend. And if you haven’t already, join us on Facebook and follow us on Twitter. For related traffic news, check out Dr. Gridlock.

November global temperature review: NOAA reports the average global surface temperature was 12th warmest on record (since1880) in November. It was the 321st consecutive month with global temperatures above average. Sea ice extent in the Arctic was 3rd lowest on record.