Update On Today And Thursday NightJanuary 16th, 2013 at 2:51 pm by Jeremy Wheeler under Weather
I’m sitting here looking at all of the weather data this afternoon. There are two main updates, but I will be quick on this blog. The first update is that the front stalled out south of Hampton Roads. Some North Carolina cities will make it into the 60s, but Hampton Roads itself is going to stay much cooler. Highs now look like they’ll be more in the upper 40s to near 50. That is huge because the models really didn’t do well with the warming. So keep that in mind with my second update…
The computer models have been trending colder and wetter Thursday night into Friday morning. The NAM model is quite impressive with several inches of snow for Richmond and even a couple of inches for Hampton Roads. The GFS is also showing snow for a good bit of the area. The main area for potential snow still looks like it will be from Richmond/Williamsburg east through Gloucester and then over to the Eastern Shore. That includes the Eastern Shore. That whole area is currently where I do think 2-3 inches could fall. That is because I do think temps will get low enough for some snow to stick after the changeover. However, Hampton Roads itself is a tougher sell for me. Our model (6z run) still didn’t show much in the period as it had a mix until the very end. The high resolution 4km NAM is also not showing much for here. The surface temps just look too warm until last minute, and the 540 thickness line doesn’t move through until just before 7-8am. I also tend to use the 537 mark or an imaginary line just north of 540. Now the freezing line at the 850 mb (millibar) pressure level (about a mile up) will be below freezing for a good while. So that does look favorable. But a lot of the necessary thicknesses just look like they come through at the last minute between Newport News down to Chesapeake. Maybe for 2-3 hours.
At this point I have a very low confidence in the models for this possible event because, as I mentioned, the models have been doing a terrible job with the recent weather. What was NAM MOS forecast today??? 50 something? Was it 60 yesterday for today? I bet Norfolk doesn’t even hit 49 now.
Here is the latest model from the National Weather Service in Wakefield. It’s kind of in-line with my latest thinking.
I believe that is from their model. While the event is getting closer, I do still think it’s a bit early to put a stamp on amounts. I do still think today’s temps will affect and change the 0z model runs. It may make it even colder, but it could also shift the track of the low farther south. Let’s see that would put us closer to the edge of the precipitation cutoff yet make it colder. Making for an even bigger headache. Yep, that sounds about like how are typical Winter forecasts are. Stay tuned! Oh and some folks have been wondering why I have lower numbers than the models. I think initially the changeover will consume the first snow that falls. Plus the ground will be wet. So a lot of the first snow will likely melt until the cold air can get blown south. Again, a lot of it will probably melt in the metro. So I also don’t want to get too many people’s hopes up. Anyway, have a good one and try to stay warm/dry. Meteorologist: Jeremy Wheeler