The morning models have come in weaker with their simulations for today’s developing Nor’easter. This means for the Washington, D.C. area our chances of seeing much more than conversational snowflakes have dropped. Even areas up towards Baltimore, where winter weather advisories are up, may get fringed by the storm and miss out on accumulating snow.
As we discussed yesterday, we need steady precipitation to fall in order transfer cold air down to the ground. Right now, temperatures are rising above 40 - favoring rain or some sort of rain/sleet/snow mix if precipitation is light. And it looks like light precipitation is what we’re going to get. The window for precipitation is between noon and 9 p.m. today (3-7 p.m. best chance).
If somehow heavy enough precipitation moved in, temperatures might drop and precipitation would transition to mostly snow. But the chances of that now appear dubious, unless you head up to northeast Maryland or more likely southeast Pennsylvania, where winter storm warnings are in effect.
Even in places like Philadelphia and Trenton, where forecasts are for 2-5 inches of snow, I’d bet on totals on the lower end of the range based on the skimpier precipitation totals being spit out by the models this morning.
I’d give only 50 percent odds of seeing snowflakes in the Washington, D.C. area and just a 10 percent chance of enough to whiten the ground. Odds increase a bit to the northeast. If you’re in Baltimore, I’d say there’s a 60 percent chance of snowflakes, and a 40% chance of enough to whiten the ground, and about a 1 in 4 chances of seeing an inch.
The Maryland State Highway Administration is cautioning the afternoon/evening commute may be difficult, but we don’t expect issues in the immediate D.C. area. Roads are more likely to be wet than slick, even up towards Baltimore. Perhaps in places like Harford county, if snow intensity is high enough, some slushy travel and reduced visibilities are possible.