Monday: Pattern Change on Track, Snow this Weekend?

Good morning. Everything I laid out in my prior post regarding the pattern change so far is playing out as expected. Long range models are now showing a flip towards a sustainable winter pattern within 10 days.  This pattern then has the potential to last well into February. Winter is coming!

In addition to this, we also now have to watch later this weekend for a potential storm. As always, details are unclear but there will be cold air in place and some signals suggest snow on Sunday. I have upgraded my Winter Outlook index to a moderate threat for this period. I will be discussing this more below.

Staring off, this week will feature more seasonable weather for most of us and much needed snow returning to the mts of New England...

Notice how tomorrow morning some snow/ice is showing up for NNJ. Be careful as roads can be slick for tomorrows commute.

The focus however is New England and the mtns continue to see snow as we progress through the week...

When it is all said and done I expect around a foot to fall for the central and northern ski area peaks by the end of the week.

Then we turn to the weekend. This departing low pressure system that will cause the snow in New England is a key feature...

When I see a vortex of low pressure develop in this region, it is a signal to me that there is a mechanism to lock in cold air along the east as seen below with cold high pressure...

The consequence of this is to favor a better chance at snow for any storm that wants to develop behind it. Of course for a storm we need other factors to come into play. Those factors are on the field, it just is a matter of if they come together...

Looking above I labeled a few areas. The vortex of NE Canada to lock in the cold air and aid in blocking the jet stream. Two pieces of energy that need to come together and a western ridge.

Just because these factors are on the field it does not guarantee a storm, but it certainty increases the chances as those two pieces of energy are more favorable to come together in a setup like this. 

The models are all over the place. The GFS has a snowstorm Sunday..

The European is flatter and out to sea...

Its ensemble system is more west...

Bottom Line: Nothing is set in stone but we have enough evidence to monitor a potential winter storm for later this weekend. By Wednesday we should have a better handle on some of the key details I discussed. Stay tuned!