A powerful winter storm has been wreaking havoc on much of the central United States, but as it moves east it will weaken. High pressure gave us a sunny and beautiful (though cold) day in the D.C. area ahead of this system. As the storm progresses to the east coast, clouds will enter the region overnight, and precipitation will enter the western suburbs by later tomorrow morning.
What you should expect:
At this time, our team thinks that precipitation will start in the form of some light snow around lunchtime tomorrow in the D.C. metro and a little earlier in areas to the west. This snow will quickly change over to light sleet and possibly even some light freezing rain and continue through the afternoon and evening. Below is a look at a model forecast for tomorrow around Noon. This may be a little overdone as far as precipitation but the type looks spot on with some snow, sleet and freezing rain in the area.
- 4km NAM Model for Noon Friday (WeatherBELL Models)
Even though this will be an event with a long duration, precipitation totals do not look very impressive. Current model guidance only depicts around a tenth of an inch of liquid equivalent for the D.C. area. With temperatures hoving around or just above freezing, the roadways should mainly just be wet. An isolated slick spot may still not be out of the question for the afternoon and evening commute.
As of now, there are no advisories posted for our area but they are currently up over West Virginia and southwestern Virginia along the I-81 cooridor. Precipitation should change to rain Friday night into Saturday morning, and more rain will be possible through the day on Saturday as a new low forms and moves off the east coast. The heaviest rainfall totals from this new low should be over the Eastern Shore.
- ECMWF Forecast for early Saturday Afternoon (WeatherBELL Models)