The following two images (courtesy WxBell) show you visually just how bitterly cold it may be during the later half of the upcoming work week:
The latest European Ensembles are currently showing surface temperature anomalies (departure from average) on Friday December 16th in Celsius below.
Let’s zoom in on the Mid-Atlantic and New England: If the models are correct, we would have high temperatures running some 25 degrees below average across the Washington and Baltimore Metro Areas.
In the image above, notice how the cold air is seeping down the eastern side of the Appalachian mountains into the Carolinas and northeastern Georgia… this is setting up a Cold Air Damming (CAD) event for next weekend!
The next image reinforces the “CAD” viewpoint as you can see the blue colors holding strong east of the mountains with West Virginia and eastern Kentucky warming up.
So let’s put the images above into something we can quantify by looking at the latest European Meteograms (a graph of potential outcomes in temperature, precipitation and snowfall accumulation) for National Airport, Dulles, BWI, Frederick and Fredericksburg for the upcoming week:
- Bottom of graph currently shows 7″ of snow accumulation potentially on the 17th (next Saturday)
- Notice temperatures dipping into the lower to middle teens in DC on Friday with highs holding in the lower to middle 20s! (Look at the two horizontal color bars above the temperature line graph). T2M Max (2 meter or surface high temperature); T2M MIN (2 meter or surface low/minimum temperature) shows just that.
- The black numbers on the left hand side of the graph are temperature (F) and the smaller numbers on the bottom right of the graph are showing precipitation (in liquid; remember 1″ of rain typically equals 10 inches of snow near freezing).
- Coldest air of the season will march through our area Thursday night into Friday
- We will have to watch a storm system next weekend that could produce our first significant winter storm (snow, sleet and freezing rain)