ers-wxman1

Steady snow in Reston, moderate at times. Rates seem better than Monday morning. Bet we see closer to 2”

In what way has it been horrible? It did very well on the last event.

5.5-6” in Reston. Second event getting underway.

Will have to wait and see how the evening round pans out, but thus far the HRRR, NAM 3K, RAP, and EURO were overdone, especially the high res - more like 30-40% overdone. I recall the HRRR showing 12-15”, it at least corrected some yesterday. The GFS and even to some degree the ICON had the right idea with heavier totals S and E.

1.5”, snow picking up. All surfaces covered.

Steady light snow, flakes increasing in size. Coating on all surfaces.

Very light snow has begun here. I’m 2N of Reston Town Center.

Dewpoint up to 19 at IAD. Should be another 30 min to an hour before the hole fills in. Always something around here to throw things off. Snowing at the FAA Command Center in Warrenton, my boss says.

I’m on shift this evening at the Command Center. Can tell you the convection down south is significant…tops over 40,000 feet in January. The tap is out of the gulf into very cold air. The rates here will be impressive after midnight and I would expect the snow to pile up fast so the high res models that have been showing this are likely correct. Do believe we will see 90% of our snowfall up until 10 am Monday/15Z. Upper pattern looks reasonable to support light snow into Monday night. South of 66/50 still could see a few pingers mixed in with all the WAA and latent heat release but not too significant. Dynamic event and I always side conservatively in here.

As exciting as it looks, take the HRRR with a grain of salt. If all of the high res models begin converging on a 12+ area wide event then it may be on to something.

HRRR goes bonkers on frontogenetical forcing in a cold column. I’ve seen it both overdone and underdone and when it busts it’s usually a bad one. The elements are there for heavy snow but we are not seeing a true upper level phase that would produce this type of snowfall. More so a 6-10 inch event with a few pockets of 12 is more likely in this setup. 90% of our snow will fall between 2 am and 10 am, purely WAA with frontogenetical banding. Beyond that it’s more complicated with the pass of the upper low and development of the coastal which will not phase.

Still snowing at 18z per NAM

Warning level snowfall for much of the sub forum. North of I-66/50 likely to see 6-10”, south mixing likely to an extent, but big question is how will the upper levels evolve and how quickly can the coastal get organized. Potential for an uptick with future runs if the 850/700/500 can close off or at least take a favorable south of the region track. Cold air in place. This is our best shot in several years.