Sunday Snow PotentialFebruary 17th, 2012 at 9:08 am by Jeremy Wheeler under Weather
We’ll get to the white elephant (snow potential) in the room soon. But first I have to talk about this morning’s fog. It was very thick in some places. We had visibilities down to about a half mile or less in many locations. There were even 2 school delays because of it.
- Visibility This Morning
The fog and clouds will burn off later this morning. Then we’ll get to some nice weather this afternoon. Other than a northwest breeze at 10-15mph this afternoon things will be great. That breeze will make it feel a little chilly near the shore. A big area of high pressure will produce dry conditions for both today and tomorrow.
- Today’s Weather Map
The high will keep sliding east through our region tomorrow. The focus then will be the low that will come out of Texas. The general idea is that the low will move up into our region through the day on Sunday. This will create wet weather for most of the 2 state region. There will be colder weather near the Appalachians, so Snow will be possible there even during the day. There is a high potential for snow from Charlottesville to Richmond to Washington D.C. Hampton Roads can expect some snow on the back side of the low as it moves offshore, but it’s hard to tell how much will stick to the ground. This will happen Sunday night. The timing of a few elements are critical to this forecast. It’s like a big chess board where the pieces have to line up, but the pieces also have to line up at the right time. The track and timing of the low is the thing to watch with this one:
- Sunday/Sunday Night Forecast
I’ll do the big blog routine now where I’ll do some complicated model talk in the next paragraph. I’ll give the general overview after that. So you can skip down to the bottom if numbers and computer models aren’t your thing.
The Models: The European model has gained a lot of attention in the last couple of years. It is a very expensive and powerful model from my understanding, but it has shown great skill in forecasting snow out 3-7 days. It has been showing an area of low pressure to skirt our region, but it is weaker and a little slower than the other models. It actually isn’t showing too much snow with it’s latest scenario. It has rain for most of the region until around midnight. Then it has a light changeover in the viewing area. A few flurries and scattered light snow showers through about 5am Monday. The GFS is quite a bit wetter. It has moderate snow over a good bit of western, central, and northern Virginia from late Sunday afternoon through early Monday morning. It brings in the changeover to southeast Virginia after midnight. I pulled out Bufkit, and it shows the GFS with a half inch of accumulation in Norfolk and with about 5 inches in Richmond. Whoever doesn’t get the accumulating snow will at least see flurries or some scattered light snow showers (all the way down to North Carolina) into about 5am Monday with that scenario. The NAM also picks up on this system. It has snow over western and northern Virginia Sunday evening. Then it brings a changeover to Hampton Roads around midnight. It’s scenario though has mostly rain with only a brief period of snow. Most of which would probably melt. This model usually has a better handle on the temperature profile, but the GFS almost always handles offshore lows better. So we’ll see which direction these models trend in the next 12 hours. Finally, the Canadian model is similar to the GFS. It has a heavy band of snow that might stick due to its timing from Emporia to the Peninsula to the Eastern shore northward. It only has a brief changeover from the southside into North Carolina. These are the latest model runs, but the morning (12runs will be in soon). Either Jeff Edmondson or I will update at midday if there is a big difference in those runs.
The Overall: The good thing here is that the models are in fairly good agreement now as to the pattern and timing. There are differences, but I’m surprised as to how much agreement there is compared to 24 hours ago. No matter which model you go with, all of them show some snow in the region Sunday night. How much will stick is the questions. There is no doubt that it will all start as heavy rain. If a lot of rain falls, then remember it is tough to get the snow to stick unless you get that air temperature down to 30 degrees for about 20-30 minutes. The only way you will get that to happen is to push the cold air down from the north. That can happen with a northerly wind, but the European and NAM models have more of a northeast wind through the period. The wind direction depends on how soon the low can strengthen as it pushes offshore. At this time I’d say that the metro has a 40% shot at accumulating (more than a dusting) snow. The Northern Neck has a 60%. The Richmond to D.C. area….80%. One thing to remember is that the longer range models don’t have the resolution to show the likely scattered nature of the snow as it moves in. So I would expect the snow amounts to be a little clearer in the next 24 hours. HPC (A branch of NOAA) has a nice graphic that shows the chance for a certain amount of snow on a map. Check it out here: HPC
I’m very vested in this forecast as A. I will be in Monday morning to cover whatever is on the ground, and B. My mom is flying out Sunday night. So I actually hope conditions aren’t too bad for her flight. Despite being vested I am trying to stay objective.
Meteorologist: Jeremy Wheeler