The Stormwatch 7 weather team has been working together a lot today trying to figure out the forecast over the next 24 to 36 hours. Our main thought is that this is a two-part system. The first being a clipper moving through the region tonight into Monday morning, and the second being the development of a coastal low which will take over tomorrow afternoon off the Delmarva and rapidly intensify as it moves into the northeast tomorrow night. Here is the latest.
The D.C. Metro is under a Winter Weather Advisory from 2am Monday morning through 6pm Monday evening. Areas of rain are already beginning to enter the western portions of the area and will continue to spread east overnight. Temperatures are still well above freezing and even eclipsed the 50 degree mark earlier today so will need to cool drastically overnight. Temperatures will cool into the 30s tonight into Monday morning, and rain will begin to change to snow late tonight closer to the Mason-Dixon line, and eventually to snow closer to the D.C. Metro tomorrow morning.
At this point, we think precipitation will change over to snow around the morning commute or towards the tail-end of the morning commute. Even IF precipitation changes over earlier, surface temperatures should still be just above freezing, so snow should be able to melt on contact with the roadways everywhere from eastern Loudoun, Montgomery and points east.
Locations that have seen colder air longer will have the chance for some accumulation on the roadways. Those regions include northern Loudoun and Montgomery Counties and points west. The highest likelihood will be in the warning area for Frederick Co. (VA), the Panhandle of WV and Washington Co. (MD) and points west.
The clipper's energy will transition to the coast Monday afternoon and light snow will continue to be possible throughout the day once it transitions from rain. The low is forecast to rapidly intensify off the east coast tomorrow evening into tomorrow night and race up the east coast.
When this happens, some heavier snow bands may be able to set up along and east of I-95 while the system is gaining strength off the coast. This will be the second part of the storm and another chance for disruptive snowfall in the D.C. Metro.
Currently, a Winter Storm Watch is posted along the Chesapeake Bay and points east Monday evening through Tuesday morning. There is a potential for 2-5 inches of snow in those areas along the Bay, with drastically more possible farther north and east along the Delmarva and into the northeast.
If the banding sets up a little farther west, the D.C. Metro or areas east including Charles, Prince Georges and north to Howard and Baltimore will have the potential for 2-5 inches of snow as well. Right now, there is a fair amount of uncertainty and we will have to follow the radar trends as the storm develops.
The D.C. Metro will have the potential for 1 to 3 inches of snow, with more north and west in some of the higher elevations as well as north to Baltimore and the Mason Dixon line. Regions south of D.C. such as Culpeper to Stafford and points south will have the chance for the least amount of snow from both portions of the storm.
This is a very difficult forecast and we will be doing our very best to keep you updated with the very latest information. Be sure to follow our facebook and twitter accounts and be sure to watch Eileen Whelan tonight on Newschannel 8 and ABC 7 News at 11pm. Jacqui Jeras will be live starting at 4am on ABC 7 News tomorrow morning and Newschannel 8 with Brian van de Graaff will start at 5am with the latest updates. Be prepared for delays, closings and travel disruptions through Tuesday morning.