After a relatively tranquil and mild stretch of weather, it becomes volatile tonight and eventually wintry. A powerful cold front drives through the region bringing a period of heavy showers and gusty winds. On Friday, conditions remain windy and unsettled with variably cloudy skies and a chance of rain showers that could mix with snow.
Through Tonight: Rain showers move in from southwest to northeast early this evening. Some of the heavier rain probably falls between 10 p.m. and 1 a.m. when winds also start to pick up. Rain ends by 4-5 a.m. in most spots, with average amounts around 0.5 inch (locally heavier/lighter amounts possible). Temperatures may actually rise until the pre-dawn hours (into the 50s), when they’ll then sharply drop back down towards 40. Winds begin the night out of the southerly direction before shifting to out of the west by morning - sustained at 15-20 mph with gusts to 30 mph (higher gusts possible to the southeast, near the Bay in southern Maryland - where some thunder is possible)
Friday: Skies are variably cloudy with the sun out at times. But pop-up showers are possible (30 percent chance), which may even mix with snow, especially west and northwest of the beltway towards the evening hours (no accumulation). Temperatures pretty much hold steady - between 40 and 45. It’s plenty blustery with winds from the west at 15-25 mph, gusting up to 40 mph perhaps. It will feel MUCH colder than any other day this week.
Christmas precipitation? Post Christmas storm?: Of interest, the GFS model is trying to bring a weak weather system through the region Christmas eve into Christmas morning. Precipitation type is a question mark but there could be enough cold air for some ambiance snow or a wintry mix. It would not be a big storm. A bigger deal storm system may approach the region December 26-27 with ice, rain and/or snow all possibilities. We will have more detail on both of these systems tomorrow.