Snow chances next week?

The buzz has been around for a few days and while I have been talking about it there are a few words of caution. We are just now getting closer to a time where some specifics are starting to come into clearer focus. There are still some serious doubts about the track and location but there’s no denying that the pattern is very conducive for a winter storm in the Southeast to the Mid-Atlantic. I should mention we are still getting snow flurries and snow showers this weekend across the Piedmont but no accumulation is expected. I wouldn’t be surprised to see a dusting to a half-inch in a few localized areas Saturday evening. Overall it’s just an appetizer for the larger possible storm next week.

Next Weeks Storm:

The storm system is currently over the Pacific Ocean.

Which means we don’t have the greatest data going into our numerical weather models right now. Remember there is limited to no surface or upper air stations over the vast areas of the oceans. So the sampling of this storm is not very good right now which should always be a word of caution when forecasting a storm. That changes this weekend when it arrives on the west coast.

Then things start to get interesting as the 500mb low and vorticity crank up and move southeast into the trough on the east coast.

By the time it gets to the Carolinas it has both some cold air and plenty of moisture to work with. Here’s a animated GIF of the entire journey into the Carolinas.

The interesting thing about this storm is the strong indications on the GFS model and even the ECMWF model of a deformation zone forming. These zones are areas of intense lift and cooling that usually means heavy snow banding. This is the 700mb vertical velocities or lift along with moisture at that level. The 700mb level is your ideal snow growth region.

How Much Snow?

This far out it’s really hard to say because the track could move just 50-100 miles and make all the difference in the world. I suspect we will see this start as a rain snow mix and change back to snow. The real chances of a significant storm would hinge on the placement of that 700mb deformation zone. That would form on the northwest side of the low track. The GFS model output for snow looks like this.

While the ECMWF looks like this right now:

Final Thoughts:

I’m not sold completely yet on this storm due to the lack of good model data to this point. The pattern is there so a storm is likely. The location and track though is currently in doubt. This could crank up after it moves through and we see nothing. Yet the one thing that is also worth noting is the intense blocking going on in the North Atlantic. This blocking can really lead to big east coast storms, but it also plays havoc with the model data. The numerical models have a tough time resolving storms in this type of pattern.  So for now I’m leaning towards a rain/snow mix with little accumulations. I suspect this could be more of a Mid-Atlantic storm, VA/MD/DE storm than a NC storm. I will have a much better idea and feel much more confident this weekend once the storm is over the west coast. Stay tuned!