This is a very in depth (Nerdy) update on the storm potential, so for all of the “I just want the facts people” here is a brief overview.
•All major models support snowfall between Thursday and Saturday
•The probability of a minor to major storm continues to increase, but is not yet certain.
•Snowfall accumulations vary greatly based on details that we are two early to iron out.
•Begin to factor this storm potential into your plans.
We have been discussing a potential storm threat for the Thursday AM thru Friday PM period since late last week, and as of today, the probability continues to increase. While the forecasting models do all support snow for this timeframe, they all have a different opinion on how much. Lets try to break things down a bit as of now, so everyone can see the range of possibilities at this time. Keep in mind that this is NOT a forecast, but simply providing you with all of the possible scenarios.
European Model (Worst Case)
• This model continues to paint the worst picture with heavy snow, on the order of over a foot, region wide.
•Gusty winds between 20-40 MPH, blowing a drifting snowfall.
• Long duration snowfall of varying intensity from 8am Thursday through Saturday at 8pm.
•Temperatures only in the low teens means, dangerous wind chills, high ratio snow of 20-1+ also means difficult to maintain roads at these temps.
•Track is closest to the region compared to other models.
Below is the snowfall forecast from the European Model….
Here is another image showing the track of the system…
GFS Model (Strong Storm)
• Still a significant storm on the GFS model, with less snowfall across the region on the order of 8-12+ inches.
•Winds are not as big of an issue, storm is not as deep or as close to the coast, so winds are mostly offshore.
•Temps also in the low teens, so high ratio snow means more than what the model is showing, same difficulties in maintaining road conditions.
•Also a long duration snow of varying intensity from Thursday through Saturday
•Further South track from European and not as deep of a system (central pressure)
Below is the snowfall forecast from the GFS model…
Here is the GFS model track of the storm..
CANADIAN Model (Weakest)
•A much weaker storm with snowfall between 3-6+ inches
•Being the furthest South, wind is a non issue with this scenario.
•Still cold, high ratio snow
•Shortest duration, snowfall from Thur through Fri
•Very suppressed system that grazes the region
Below is the snowfall forecast from the Canadian Model…
The storm track from the Canadian Model..
So as you can see we have some differences between the forecast models, this is where the actual forecasting comes into play. The Canadian Model should be dismissed as an outlier at the moment, and a blend of the GFS and Euro Model is the smartest approach. Also keep in mind that none of these track are the ideal track for a big nor easter, we are in a positive NAO state, which in laymen’s terms means there is no blocking in place to force the storm tighter to the coast, this is why all the models take the storm more NE, and away from the coast. A lot of people are happy that the European model came South today verses its overnight run, one thing to watch is that the model doesn’t keep trending South and remains suppressed like the Canadian model. There is a very strong 1032-1036 High Pressure to our North, that is supplying us with this cold air, with no blocking it can also be strong enough to keep the storm south, which is something to watch closely. One other item to keep in mind is that all snow maps, put out by these models are defaulted at a 10-1 snow ratio, keep in mind that temps in the teens can spell out 20-1 or even high snow ratio’s, meaning only one inch of liquid can produce 20 inches of snow. The short of it is, there is still a lot of details to be ironed out but the most responsible forecast as of this afternoon is to be prepared for the possibility of a moderate to heavy snowfall, Thursday into overnight Friday.