Some wintry weather (finally)?

Robust cold air advection has finally set in (it's January 20!), and precipitation will begin falling here by midnight. The combination of the two should give us our first true accumulating wintry precipitation event: up to 1" of snow, then a quick changeover to sleet, then to freezing rain, then finally to rain. By 15Z (10 a.m.) we should be all rain in Annapolis. This will be an interesting event to watch, for several reasons: (1) sleet/freezing rain are less common here than snow or rain; (2) surface cold/dry air is more entrenched than NWP models are predicting (we're at 34F/12F in Annapolis now, which gives a wet-bulb temperature around 25F - plenty cold for freezing/frozen precipitation. Locations to our east and north are similar (34/12 at Cape May, NJ; 36/10 at Ocean City, MD), so it will take a while to advect in warmer air. Thus we'll have to see how things pan out.

Of course I have a flight tomorrow at 11:35 a.m. to New Orleans for the AMS meeting. I expect some delays, but hopefully not an outright cancellation (although with how tight Southwest's flight schedule is, given that my plane will have already likely made 2 take-offs & landings by the time it leaves BWI late-morning, nothing is certain). Here are NAM model predictions of 2m temp, accumulated snow, and composite reflectivity, all valid at 7 a.m.