Over the last several days, we have been tracking the potential for a winter storm to impact the region. As the forecast has come into better focus, a winter storm does, indeed, seem to be very likely for much of the Mid-Atlantic on Monday. Many will see snow, with far southern areas potentially seeing a mix of snow and sleet.
Storm Overview: A developing storm will cross the Plains this weekend and move by the Mid-Atlantic by Monday. Cold air will settle into the Mid-Atlantic this weekend, which will set the stage for winter weather. The more cold air that is present the further south this system will go.
A band of heavy snow is likely along the northern edge of the precipitation. Just south of that will be a wintry mix of heavy snow, sleet, and potentially freezing rain. The cold air placement will dictate where those line up in our region.
Timing: Our Futureview Model (powered by WeatherBell) shows precip moving in late Sunday night, well after sunset. Temperatures will likely be cold enough for this to start as snow area wide. I have placed the temperatures on the maps so you can see how close the “warmer air” (temps above 32°) will be and what makes this a tricky forecast.
Throughout the day, areas south of DC will be dancing around the freezing mark. This will allow for a wintry mix of snow, sleet, and freezing rain to take hold during the midday hours. Heavy snow will be focused north of DC at this time.
There may be some dry pockets that work in during the midday hours as the mix of snow, sleet, and freezing rain takes hold. Because of this, I am not overly worried about big ice totals in Southern MD. By this afternoon hours, cold air returns and switches many areas back to snow. The snow looks to move our Monday evening.
Snow Forecast: Right now, the “bullseye” locally looks to be setting up in northern Maryland and southern Pennsylvania. This is where 5-8″ of snow seems likely. Totals remain moderate even south of DC, where 3-6″ is likely. Totals are slightly lower due to the potential for a couple of hours of mixing. Snow totals will fall off south of Tappanokck, thanks to more rain down there and north of Harrisburg, thanks to dry air.
Ice Forecast: As mentioned, sleet and freezing rain will mix in at times for areas south of DC. Sleet looks like ice pellets while freezing rain creates more of a glaze. Only minor amounts of ice could cause issues. I expect some issues south of DC where up to a tenth of an inch of ice is possible. Greater amounts and impacts are likely to the south.
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 will the exact axis of heavier snow be 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? Right now, 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:
10% chance: 1-2″
25% chance: 2-4″
40% chance: 3-6″
25% chance: 6-10″+
Could more or less snow fall than currently forecast? Certainly. If the storm were to take a more northerly track, we would see that icy mix zone and the heavy snow zone shift northward. This would likely only lead to a couple of inches of snow in southern MD with the “bullseye” in southern PA. Likewise, if this storm were to shift southward, the heavy snow and icy mix would shift southward. This scenario would put southern MD in a potential bullseye.
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.
What impacts may we see? The mix of snow and sleet areawide is likely to cause widespread, high impacts. Travel will be quite difficult on Monday. As a result, I believe that school and business closures are likely for Monday. We may see these impacts linger into Tuesday, as well.
Any chance of a wintry mix of freezing rain or sleet? This is certainly a risk, especially for areas south of Washington. Sleet will likely mix in at times in southern MD, with more prolonged icing in central VA. This wintry mix zone could shift north or south, though!
Concluding Thoughts… It looks very likely that much of the Mid-Atlantic is on tap to see our first Winter Storm in nearly 2 years. Heavy snow and sleet are likely on Monday. Granted, questions remain on the exact track of this system. Slight shifts, either north or south, will cause big changes in the forecast. This is why it will be important to stay tuned for updates as we learn more about the atmospheric setup and how the conditions evolve.
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!
William Richmond Inc. Roofing & Siding. William Richmond Inc. is your trusted roofing and siding contractor in Southern Maryland. Our services include roof installation and repair, siding replacement, gutter installation and repair, and window replacement. Contact us today for quality workmanship and exceptional customer service.