Radar at 12:14 AM

Tonight I believe I have seen some of the heaviest snowfall I've ever observed.  Rates are 1-2.5 inches an hour and more very heavy bands are headed this way.  In the radar below, you can see two things.  The first is that as the low in the Appalachians transfers its energy to the coastal low off of North Carolina, it has brought a surge of warmer air with it.  Radars tend to be poor at judging rain/snow lines, which is why it looks in the radar below that rain has edged into DC and points south when I can see outside that it has not.

But there is some mixing going on in central Virginia and further south of the DC metro.

As the low off the coast rapidly intensifies (mets refer to this effect as "bombing") more cold air will be drawn in and will change the precipitation that is mixing back over to snow, possibly as far south as Norfolk.

The other thing you can see is the dramatically heavy precipitation that's going on.  Those dark blues are the bands I spoke of and they are where the snow is falling at tremendous rates.  See that yellow line above Richmond?  That's another locally heavy band of what is likely sleet.  As it moves due north and hits the colder air, it will be yet another burst of heavy snow for our region.

11.5 inches here in Arlington.  More to come...