12:05 PM | **Sunday PM: An active week coming up with another Arctic blast and three precipitation events**
Paul Dorian
12Z GFS forecast map for early Thursday morning with potential snow (in blue) showing up around here as the next Arctic air mass blasts into the region; map courtesy tropicaltidbits.com, NOAA
This December is a far cry from last year which ended up warmer-than-normal virtually throughout the entire nation. It has been colder-than-normal so far this year throughout a good part of the nation and another significant Arctic blast will cross the northern US this week - reaching the Mid-Atlantic region on Wednesday night and Thursday – and this blast will be colder than the last one.
December 2015 temperature anomalies (warmer-than-normal in red, orange); courtesy Weather Bell Analytics, NOAA
In terms of precipitation events, the first system of this active week is already causing snow shower activity across Pennsylvania, Maryland and Virginia and precipitation will tend to expand in coverage this afternoon; especially, north of the Mason-Dixon Line and continue off and on into Monday with raw conditions. Anything that falls today should be in the form of snow in the Mid-Atlantic region, then snow, sleet and/or freezing rain are likely tonight, and primarily plain rain is expected on Monday as milder air pushes in from the southwest. Across northern Maryland, northern Virginia and DC, there can be a dusting of snow today with some messy conditions tonight (i.e., snow, sleet, freezing rain) before a changeover to plain rain. Across Pennsylvania, NJ and southern New York, this first system of the week can produce anywhere from a coating to an inch or two of snow and ice later today and tonight and then primarily plain rain is likely on Monday.
December 2016 temperature anomalies (colder-than-normal in blue, green); courtesy Weather Bell Analytics
The next threat for precipitation will come with the onslaught of the next Arctic blast later in the week. Specifically, I believe snow showers and perhaps even heavier snow squalls will be quite possible in the I-95 corridor later Wednesday, Thursday and even into Friday as this next Arctic air mass floods the region. Temperatures may be confined to the 20’s for highs on Thursday and Friday and strong winds will generate even lower wind chills in the I-95 corridor. After that, the third threat for precipitation comes next weekend as this next Arctic air mass begins to retreat from here to the north. Lots of moisture will head our way from the western states as the Arctic air begins to retreat and this could result in a weekend scenario of snow-to-ice-to-rain.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com