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By Chris White

Weather Blog: Since Fredericksburg resides "in the seam" between the Richmond VA and Washington DC media markets this blog is a look at the weather from a Fredericksburg-centric point of view.

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THE snowstorm of this winter

FORECAST: Check here for the latest from the NWS.

CLOSINGS: Check here for weather-related schedule changes.

POLL: Are you buying it?


Okay, I’m finally ready to admit that the upcoming storm looks like the real deal and will provide the snow lovers with the event they have been clamoring for all winter long.  In fact the counties along and west of Interstate 95 are under a Winter Storm Watch from the National Weather Service (NWS). The exact forecast for any given point is very challenging as indicated in this morning’s area forecast discussions of all three Virginia-based NWS offices.  Here’s one quote from the Sterling office which covers Stafford, King George, Spotsylvania, and the city of Fredericksburg (but not Caroline county):

“THE RAIN/SNOW LINE WILL CONTINUE TO WAVER OVER THE SAME GENERAL AREAS WITHIN A FEW MILES OF THE I-95 CORRIDOR OVERNIGHT AND INTO WED.”

That “wavering” will greatly affect the snow totals at any given spot on the map as the surface temperatures will be within one or two degrees of the freezing point (32 degrees) for most of Tuesday night and Wednesday when the bulk of the snow will fall.

The city of Fredericksburg (note the specific place reference here) will see rainfall starting mid-afternoon Tuesday with a high temperature in the middle 40s (F).  That precipitation will begin a changeover to a mix of rain and snow by late evening (after 10 p.m.) and it looks like that mixture will continue throughout the night as the low temperature hovers very close to the freezing mark.  Snow accumulations in the city look like they will be very light by dawn – perhaps an inch – but the western portions of Stafford and Spotsylvania counties could see more than that as those areas will be just a tad cooler than the ‘Burg overnight Tuesday.

Then at 7 a.m. Wednesday here’s the official NWS surface forecast map:

Having tracked south of our area the surface low – the red “L” over Virginia Beach – will begin to intensify as it reaches the coast.  This intensification will accomplish two things that will increase the potential for accumulating snow over the ‘Burg.  First, the dynamics of the storm strengthening will create the potential for “snow banding” which can dump a lot of snow in a short period of time.  Secondly, as the low pressure center moves off the coast the counterclockwise winds around it will shift to a northerly direction over Fredericksburg and yank down colder air from the north, also increasing the snow potential. (And those winds could be strong enough to create problems with downed tree limbs and power outages when you add in heavy wet snow.)

The combination of these factors will lead to the city receiving the bulk of its accumulating snow Wednesday afternoon and evening, and that is reflected in the time-based snowfall maps from NWS Sterling.  Meanwhile the overall snow depth potential is shown in this HPC graphic for the 24 hour period ending Thursday morning:

This shows areas along I-95 and westward under a high risk (>70% chance) of at least 4 inches of snow accumulating between Wednesday morning and Thursday morning.  The ‘Burg could wind up with 5 or so inches of total snow accumulation out of this event.

Now, with all this information flying at you keep in mind that this blog is focused on the city of Fredericksburg. The surrounding counties may well experience much different conditions.  The gradient of snowfall depth will ramp up rapidly as one heads west in Stafford and Spotsylvania counties and will likely ramp down rapidly in the opposite direction toward King George county and the Northern Neck.  Additionally ANY slight change in the track of the surface low center, say 10 or 20 miles, can change the overall snowfall pattern.  There are no models or forecasters that are accurate – or lucky – enough to predict that little bit of change at this point, so it would be very wise to stay tuned to official weather sources like weather.gov to stay abreast of any potential changes to the forecast.

Whew!  I’ll revisit all this tomorrow morning but for now my head hurts….

Permalink: http://news.fredericksburg.com/weather/2013/03/04/the-snowstorm-of-this-winter/