With the incoming cold blast, we have been monitoring the threat of a potential storm. Over the last couple of days, it has become quite likely that much of the Mid-Atlantic region will see impacts (in some cases moderate to high) from our season’s first winter storm!
Overview: An area of low pressure will work eastward out of the Plains late Sunday into Monday. It will bring with it a decent bit of moisture as cold air tries to drive southward. This interaction will help produce a band of snow for much of the Mid-Atlantic, with an icy mix to the south.
Scenarios: The determiner of who will get the heaviest snow and highest totals will be the cold air to the north. If the cold air is not strong enough, the storm will be allowed to come northward. In that scenario, mixing concerns could get as far north as the Mason-Dixon Line after a thump of heavy snow. A stronger cold air source would help keep the storm a but further south, focusing the heavy snow on the DC Metro area.
Models: Our modeling has come into better agreement over the last couple of days, honing in on a Mid-Atlantic winter storm. Our European model has been consistent showing the potential heaviest snows focused in the DC/Baltimore areas. This model does show some sleet/ice concerns across Virginia that may creep up into southern Maryland. Regardless, the general timing here looks to be 11pm Sunday – 1pm Monday, with potential lingering snow showers behind.
Storm FAQs
How confident are you in your forecast? I have medium confidence in this forecast. I feel pretty certain that we will see a winter storm Sunday night into Monday. The question is, where the exact axis of heavier snow will set up.
Where will the heaviest snow fall? Right now, the highest totals look likely to be concentrated from DC to Harrisburg and Philadelphia.
When will the snow start? Current guidance shows that the snow may begin well after sunset on Sunday.
When will the heaviest snow fall? Probably during the morning hours of Monday
When will the snow end? The storm should begin to pull away from the region by midday Monday, which will allow the snow to shut of from west to east by early-to-mid afternoon.
How much snow will I get at my house? It’s a bit too early to say with any high degree of confidence. Bit generally, I think we are looking at moderate accumulations with some northern areas potentially seeing more. This is all dependent on the track, though. Slight shifts in either direction will impact totals. Currently, here’s my assessment of snowfall probabilities:
25% chance: 1-3″ (more likely south)
50% chance: 3-6″
25% chance: 6″+ (more likely north)
Will the snow stick? It is likely that we will see snow accumulation on both grassy surfaces and roadways (granted, this will take time). The incoming cold shot will help to bring down ground and road temperatures.
Any chance of a wintry mix of freezing rain or sleet? This is certainly a risk, especially for areas south of Fredericksburg and Leonardtown. This wintry mix zone could shift north or south, though!
Concluding Thoughts… Overall, I think it is likely that the Mid-Atlantic will see our season’s first winter storm of the season, and likely our biggest in nearly 2 years. There are still some kinks that need to be ironed out–namely the exact track of the system. After we get new data in tonight, I will feel more confident with issuing my First Call forecast with an initial stab at those hyper-local details and impacts.
Stay with JB Weather for the latest information on impacts here in Southern Maryland and across the Mid-Atlantic. You can always access my forecasts and updates here on the website, on Facebook, on Twitter, on Instagram, and on YouTube. JB Weather is the Mid-Atlantic’s Weather Leader, and I am working around the clock to keep you ahead of any storm!