Tuesday Evening (2/17) Weather Discussion

(Posted 6pm)
Although many areas failed to get above freezing this afternoon, the higher angle, mid-February sunshine helped melt a good bit of snow off paved surfaces. This was actually the warmest weather we'll see the rest of the week.  Be careful as the combination of a setting sun and subfreezing temperatures lead to areas of refreeze in the morning.

Evening Snow-Squalls with Wednesday's Arctic Front (18z high res nam)

Attention Wednesday will be on yet another arctic front set to swing through bringing with it a reinforcing blast of cold air and additional scattered snow showers.  Although at the upper levels this looks quite similar to Saturday, there's some differences towards the surface including less moisture and flatter low level lapse rates...both meaning snow squalls shouldn't be quite as robust.  I still think a few of these survive the mountains, likely making it to the coast tomorrow night.

Shenandoah Valley Arctic Front Thoughts for Wednesday

Timing: Best chance for snow showers/flurries between 1 and 7pm.  Expect any squall to be short lived (maybe lasting half an hour or so)

Amounts:  Really depends on where you are...just flurries for some while others may see coating to a quick inch fall.

Impacts: Wind-blown snow will reduce visibility at times.  This not only applies to snow that falls, but also to the blowing and drifting of what's already on the ground.  

Following the front....some of the coldest air we've seen in years (colder than this past Sunday and the arctic outbreak January 2014) will arrive and last into the weekend.  There's a solid chance Shenandoah Valley locations end up stuck below 20 degrees for a 60+ hour stretch (Wednesday evening through Saturday afternoon).  Thursday highs may struggle to make it out of the single digits followed by below-zero lows Thursday night.  I know I say it a lot but be sure to take proper precautions for such an extended period of extreme cold (frozen pipes, outdoor pets, limiting time outside, etc).  It will be interesting to see school decisions since most buses won't be able to start.

Thursday's High Temperature Forecast (NWS NDFD)

Looking ahead, another system is on tap for the weekend.  Although this looks like it'll take a more northerly (warmer for us) track, it'll be awfully hard to erode arctic cold air completely.  As of right now, I'm leaning towards a mixed bag of precipitation types for the Shenandoah Valley area....stay tuned the rest of the week for updates on that.