Gametime for DC: March 13-14 Snow/Sleet/Freezing Rain/Rain Currfest

Finally have time to sit down and write. Well we finally clawed our way to a winter storm-in March no less. With only a few hours before the start of precipitation, details are still being worked out. The overall synoptics are clear. Low pressure currently over the Midwest will transfer energy into a developing coastal low off the SE coast. This consolidating low will then run up the East Coast, bringing widespread heavy precipitation. This in conjunction with abnormally cold air will result in frozen precipitation for many.

Current storm positions and radar

First stop for the storm is DC.

Precipitation will overspread the region somewhere between 8PM and 10PM tonight. It may begin as light rain but will turn to snow as steadier precipitation develops. In the early morning hours, as the storm cranks up and approaches, the immediate DC metro area should mix with sleet. this will likely coincide with the heaviest precipitation. Freezing rain is not far off to the SE, although temperatures will probably be too marginal for much ice accumulation. This is where details matter. The timing of the changeover and duration will vary model to model and depends on small track shifts. This will all be nowcasting. In any case, precip will change back to snow as the storm pulls away in the morning and snow may into the afternoon hours, depending on if the storm throws back any precip. That's something that is often not well modeled and often overestimated. Temperatures will be in the mid 30s.

Frozen precip accumulations will vary wildly through MoCo. Areas that don's switch over to sleet may end up with around a foot of snow. Areas that do switch over closer to the city will have much less. However, a couple inches of sleet would still be a traffic disaster so unless the storm just rains, no school Tuesday. Going to go with 3-8 inches of snow before the changeover (more north less south) and then 0-2 inches of sleet (less north more south), before 2-4 more inches of snow after, yielding snow totals of 5-12 inches across the county. A bit more than 1" liquid equivalent.

After this storm, temperatures are expected to stay well below average for at least the rest of the week with some outside chances of snow later too.