Thanksgiving Day: Preliminary Storm Forecast

Happy Thanksgiving! Before everyone gets moving about for the day I wanted to give my updated thoughts on the storm system that will impact the region on Sunday. At this time, I am favoring impacts to mostly be to the northwest, especially over New England and off the coasts. There is a chance however that we see some back end snowfall from this which will be hard to predict this far out.

Here is my preliminary forecast for Sunday. This is subject to change and is my best estimate on what will happen given all the info I have looked at. This is a very tough one to forecast and the final outcome can look a lot different than what you see below:

This storm system will feature a mixed bag of precipitation. 

For the green zone, I am not expecting major impacts at this time. Mostly rain with some snow possible on the back end of this early Monday morning. 

For the pink zone, mixed precipitation will initially fall Sunday morning before giving way to some rain as well. It is possible however that this zone sees some accumulating back end snow early Monday morning.

For the dotted blue/pink zone, this is the big wildcard. I can see this turning out to be a signifigant winter storm but it just is too early to make the bold call. 

For the dark blue zone, I am very confident there will be a moderate to signifigant snowfall


Models are pretty spread still on what this storm does. This will likely continue for the next day or so.

The reason for this is we have a low pressure system cutting inland that will redevelop off the coast. Anytime you have a redeveloping low the models struggle. You can see the overall evolution of this below...

Zooming in closer...

The GFS is the warmest and doesn't impact the area too hard except for the north...

The European is more aggressive with winter weather making it further south with wraparound snow towards the end of the event...

Using ensemble means, here is the probability of snow exceeding 3"...

Using historical analogs here is median snowfall...

As you can see my forecast map is a blend of many of these tools.


I will start to really hone in on this next several days. I am confident in one thing, that this will throw us some surprises from a forecasting standpoint over the next several days. I wouldn't even be surprised if models are still shifting 24 hours away from this event. 


Stay tuned.