Possible Big Snow In Virginia (UPDATE)March 4th, 2013 at 8:28 am by Jeremy Wheeler under Weather
SEE MIDDAY UPDATE AT THE BOTTOM:
I was at the Mcdonald’s Garden Show in Hampton over the weekend. It was a nice time where I got to meet a lot of great folks. Some of them would ask me about the upcoming storm Wednesday into Thursday. “Hey Jeremy. Do you think it’s gonna snow this Wednesday?”. One time a person asked, and you could hear a pin drop until I started talking. That was with a room full of people. Folks want to know. So let’s talk about it:
Today we have high pressure in the region. It has been a cold start with low in the 20s and 30s. High temperatures will only be in the upper 40s later today. We will see a lot of sunshine, but the winds will be out of the northwest at 10-15mph with gusts up to 20mph. This will keep reinforcing the cooler air. Darnit!
There is a large area of low pressure which will move out of the western U.S. and will develop over the next 48 hours. The low will move into western Virginia by tomorrow afternoon/evening.
This will allow a warmer southerly flow out ahead of it. This will let the moisture increase which will produce scattered rain showers throughout the region later in the day. With the warmer winds the high temperatures tomorrow will be near 50 in Hampton Roads. Snow will already start up in western Virginia by later Tuesday. As the low moves east it will continue to pull up the milder/moist air out of the southeast. This will clash with the colder air that will come down behind the low. By wednesday morning we’ll have scattered rain showers locally with rain changing over to snow over towards Lynchburg and Charlottesville.
Through the day on Wednesday the changeover to snow will keep moving east as the low slides east. All of the models agree (except the Canadian) that the low will strengthen over Virginia/North Carolina and will slowly slide offshore late Wednesday. Since the system will wrap in a lot of milder/more moist air, it’s not until the system moves to our east that we will see the changeover. This will be due to the northerly winds pulling that cold air down. So we could see a changeover in Hampton Roads by Wednesday night into very early Thursday. Our local snow will depend on how much moisture wraps in behind the system, and the track of the low. Surface temperatures are going to be tricky as well. We are expected to stay above freezing for most of the duration of the storm. However, the heavier precipitation that is forecast northwest of Hampton Roads could be enough to overcome those milder temperatures even before they pull down the colder air.
Our model tallies up the snow. I won’t give exact amounts yet, as I think this could be misleading. But I’ll give the general forecast here:
I will say that I think the D.C. area could easily see a foot or more of snow. That band will stretch between Charlottesville over to Maryland.
The models are actually in good agreement over the track. They do differ in the timing a bit though with the GFS being faster than the European. The NAM model has the most moisture hanging back, but it doesn’t do well when systems are offshore. So I don’t know if I can trust it. This system is still far away. The high resolution models will come into range tomorrow. Then we can have a much better idea for snow amounts. That is due to the temperature profiles which the hi-res models do a much better job. So stay tuned for more details. If you are traveling north (at all), then be prepared to amend your plans.
MIDDAY UPDATE: No huge updates in the forecast. The morning (12Z) updates are in. The NAM still has the most snow for Hampton Roads, but a lot of it would probably melt in the metro. All of the models still show a heavy band of snow from Charlottesville to D.C. to Maryland. The GFS really hits that area hard with barealy any snow down our way. The new Canadian actually has some snow for us now, but it has been a little variable through its runs. One interesting update is that the Hi-Res 4km NAM has some snow by early Wednesday evening even in the metro area, but it does keep surface temperatures above freezing through that time. Especially near the coast. Also, I didn’t talk about tidal flooding in my earlier update. I think we could see some minor tidal flooding on Thursday behind the system. Winds will be mainly out of the north/northwest. The seas will also build quite a bit as the storm moves offshore. So ocean overwash will be possible over the Outer Banks. We’ll have a lot more details on air this evening as the afternoon (18z) models come in.
Meteorologist: Jeremy Wheeler