Wednesday (2/18) Weather Discussion

(Posted 7pm)

Blacksburg Snow Squall This Afternoon

Another day of snow squalls in the books.  Impacts ranged anywhere from a few flurries to a quick inch or two.  That's just the nature of these things; some people get nailed....some don't.  Upslope flurries and snow showers will continue through the overnight across favored locations.  Roads may become hazardous due to both refreeze and gusty winds blowing and drifting snow across open roadways.  The bigger story remains the dangerous cold air that is now moving in behind the front and the potential for more wintry weather this weekend.  Below is a quick run down for the Shenandoah Valley.

Tonight:  Lows drop well into the low single digits...I would not be surprised to see a few locations go below zero.  Winds will gust 15-20 mph at times allowing wind chills to fall 10 to 20 degrees below zero.

Thursday: Certainly the coldest day we've seen in awhile.  Even with plenty of sunshine, high temperatures will struggle to make it into the teens.  Winds will continue to gust 15-20 mph leading to sub zero wind chills for the majority of the day.

Thursday night: The worst of the cold arrives with lows anywhere from -5 to -10 degrees.  Wind chills may at times fall below -20.  

Friday: A little bit of a warm up if you can even call it that.  Highs will make it into the mid to upper teens.  The best news will be the diminishing winds.

Arctic Cold Bottom line: We're potentially looking at a 60+ hour stretch of temperatures below 20 degrees.  Be sure to take proper precautions (protect against frozen pipes, bring in outdoor pets, limit time spent outdoors, etc.)  It won’t take long for frostbite or hypothermia in these conditions.

Weekend Wintry Potential:  We are now seeing some better agreement in regards to the track of this weekend's system.  A piece of energy coming out of the Pacific northwest will swing down and form a low in the Rockies.  This will track east across the southern plains before turning more northeast and heading up towards the Ohio Valley.  Although this track allows plenty of warmer air to flood in aloft, I'm concerned there will be enough leftover cold air initially for a wintry onset.  For the Shenandoah Valley, this looks like a snow to sleet to freezing rain mess Saturday before warm air eventually wins out and changes things over to plain rain on Sunday.  Even though high pressure will retreat into the Atlantic as opposed to holding firm and setting up strong cold air damming. there's a few factors that favor winter weather. 1) snow pack in place over the east 2) the magnitude of this current arctic air mass.  Both of these will slow the erosion of low level cold air.  Some preliminary Shenandoah Valley thoughts: 1-3" of snow and sleet followed by a glaze of freezing rain and eventually all rain Sunday.  Check back for another update tomorrow evening.

12z GFS for Saturday Evening