Friday December 16 – The National Weather Service has issued a Freezing Rain Advisory that includes Maryland’s lower Eastern Shore of Dorchester and Wicomico Counties. Cambridge and Salisbury are impacted. Also central Virginia. The Winter Weather Advisory has been extended until 1 PM for the colder suburbs northwest of Baltimore. This includes northern Harford, northern Baltimore. Carroll, Frederick, Washington, and Allegheny Counties. This is all supporting what I mentioned earlier about the cold air being slow to depart.
This split in the counties has been part of the new zone breakdowns from the National Weather Service that began in December 2014
See more about that topic here
It is important to note again that the ground is frozen solid. Computer models forecast surface temperatures for weather stations at 6 Ft above the ground. Situations like this can still have rain above freezing falling on a ground that is still frozen, thus icing up. Also any ice that develops might linger longer. I can not tell how the roads will be since that depends on your local crews. But untreated roads, sidewalks, and parking lots will be slick.
More notes below slider
Here’s the latest radar simulation from the HRRR Model. Please note this is a guide and not gospel. It does suggest a brief period of flurries or sleet around midnight passing north. But the main batch will be delayed until just before sunrise. It is possible we get snow and sleet sooner than shown here. The air is so dry that plenty of virga (sublimating/evaporating before reaching the ground. I am hedging my between on 3AM on…