Thursday December 15 – A Winter Storm Watch has been issued for Friday night through Saturday morning. This is for minor snow accumulation plus ice before a change over to rain Saturday. The map looks incomplete because the National Weather Service Office in Sterling VA issued this first for the Baltimore/Washington region. I expect the other weather service offices that include Cecil County/Eastern Shore, Delaware, and Pennsylvania will catch on by this evening. I have snow maps for all of our Mid Atlantic regions below. This doe highlight the main concern will be north of I-70 and northwest of I-95. Closer to the big cities and Bay there will be some snow and icing, but the impact is more dependent on the specific depth and duration of cold air.
- Arrival of snow: 10 PM Friday to 2 PM Saturday
- Mix to sleet and freezing rain: 6 AM to 9 AM Saturday…. later farther north
- Change to all rain: From south to north but all areas by early afternoon Saturday
- Basically if you have plans Saturday afternoon you should be fine.
- Ravens game will be wet but can end with some snow.
- Sunday: Rain may end with a mix to snow. If the front stalls, some snow could linger Monday morning near and south of I-95
Compare the GFS and Canadian Model Timelines. Multiple Snow Projection Maps Below
I will post my first call for snowfall map in this evening’s report.
The GFS is later to arrive with the snow. The first wave north in PA until after midnight. Then a faster change over to an icy mix by daybreak Saturday. The Canadian Model suggests an earlier arrival of snow, then a longer duration of icing into mid day Saturday.