Happy New Years everyone! As we transition out of 2017 and into 2018 let us look ahead to our next potential weather maker that isn’t near zero temperatures.
The facts as I know them right now:
- A storm is going to form near the northern Bahamas on Wednesday;
- It will track north-northeast and pass by New England Thursday evening;
- It will be very intense as it passes; and
- We should see some snow on Thursday.
THE BIG QUESTION: Just how close will the storm track to New England?
- Out-to-sea: Passes too far offshore and all we get is another shot of very cold air; or
- Glancing blow: Passes close enough to give plowable snow, but nothing major; or
- Major hit: Tracks close enough to give us a major storm.
Currently the computer modeling guidance is giving much of New England outside of eastern Maine a glancing blow. Something resembling this for the area (general 2-5″):
12z GFS Snowfall Forecast – Pivotal Weather
But the forecast is long from being concrete. Multiple packets of atmospheric energy will be converging on the U.S. East Coast during the middle of next week. In the image below I have circled 2 of them to point out their location as of 7 am this morning. Not circled is another packet of energy further out over the Pacific off image. My point is that the pieces of energy that will be the genesis for Thursday’s storm are a long way away and a lot can happen over 3-5 or more thousand miles.
12z GFS 500 mb Vorticity
At this point in the game it is best to rely on what are known as ensembles. Ensembles are essentially a computer modeling guidance’s way of creating a range of outcomes. From that range it is possible to calculate the probability of something occurring. Presented below is the European ensemble suites probability of greater than 12″ of snow falling from this system. For much of the region there is currently a 20-30% chance of seeing a foot of snow.
For now I will leave you with that, there are too many variables to give a more definitive forecast. This one bears watching. The storm center itself will pass our latitude at the strength of a category 2 or 3 hurricane and if it tracks close enough could deposit snow we’ll measure in feet and not inches.
Stay tuned!
-Chris
Chris Hampton Weather 