Latest on the October Snow
We've talked about a "chance for snow flakes" all week, but now, it's turning out to be a bit more than that. I'm going to try to answer what we're expecting now and how this much snow can sneak up like this, changing the forecast.
I am expecting rain and snow, often falling at the same time, to move into the viewing area late this afternoon and around dinner time. Temperatures at the onset will be above freezing and many parts of the Valley will stay above freezing through the entire night. The rain and snow will continue through Saturday morning turning to all snow before tapering off late in the afternoon. A lot of us have not seen any freezing temperatures so far this year, for that reason it will be tough for anything to accumulate on the roadways. However, other
surfaces such as trees and grass could easily see accumulating snow.
At times the snow will be heavy allowing for light accumulations in the Valley with significantly more at the higher elevations.
The higher elevations will see cooler temperatures throughout this winter storm allowing them to see more snow than rain, accumulating more snow. In those areas accumulating snow on the roadways is a potential hazard.
While forecasting, we refer to many different computer models. One that generally does really well is the ECMWF, or the "Euro" for short. For about a week it has been hinting at this precipitation moving through the area and up the coast. However, it was the only one. The GFS, NAM, and CMC (Canadian) all kept this system well to our south and then to our east, keeping us dry for the weekend.
For that reason we left a slight chance in the forecast for rain and snow, but just couldn't be completely sold on the idea of heavy precipitation. It wasn't until Thursday night and Friday morning that all of the models started coming together to any sense of agreement. Turns out, the Euro was on the right track all week!
The weather pattern bringing our snow and rain is a nor'easter, which many of us are familiar with. This time of year, normally we see these systems dump a lot of rain for us, but this time, it's colder than normal for this time of year. High pressure in New England has kept cooler air moving into the Shenandoah Valley and even more cold air will be wrapped around the low pressure system as it moves to the coast. Ready or not, snow in October is on the way!