Monday Morning Weather Update: Winter Arrives This Week

Good morning. If some of you have not been convinced by my various posts over the last few weeks that winter would come on strong, you will be after the pattern change on Wednesday. An arctic cold front cold will move into the region and likely stay put for the remainder of December. Naturally our chances at snow will increase, and the first period to watch will be from this weekend into next week for the white stuff to accumulate. There is an outside chance at a moderate snow producer later this week but I would put my focus to more on the following week for anything more significant. 

Summary:

• The weather pattern changes as a arctic front moves into the region on Wednesday
• In its wake, expect temperatures to stay in the 30's for highs during the day
• This pattern change should last for at least two weeks and likely for the rest of December
• This makes the chances of a White Christmas greater than normal
• We need to track a potential storm system for Friday into Saturday along the east coast
• At this time I do not expect any significant impacts due to my thoughts that it stays more off the coast
• Enhancement of this is possible with a clipper system on its tail
• Regardless, I would expect some light snow Friday into the weekend with some accumulations possible
• This can change so I will continue to monitor closley
• The middle of next week also bears watching for a bigger storm system to develop
• pure speculation at this time but I like the set up I am seeing
• Stay tuned for daily updates

In any case, lets take a look at the details...


On Wednesday the front moves in...

Expect rain ahead of this front and the chance for some snow to fly on the back end in areas north and west of I-95 (no accumulation). In the wake of this front high temperatures will stay in the 30's for the rest of the week. This will be a noticeable change.

We then have a situation to monitor from Friday into the weekend although I am not expecting anything significant at this time. As the pattern amplifies, a low pressure system should develop off the east coast and track northeast Friday into Friday night.....

We will have to watch this very closely as some model projections have taken this closer to the coast which resulted in a moderate accumulating snow event from the I-95 corridor. I started discussing this last week and I still maintain my view that this does not end up having a large impact. That of course can change if models start to trend more west and strong with this, but from what I see this set up favors the more out to sea solution....

Looking above breaks down the situation at 18000 feet. You are looking at energy in the atmosphere that creates storms. By studying trends in how this energy evolves you can try to nail down how a storm might behave at the surface. There are a few things I highlighted here to back up my case. For one, the trough or tilt of the pattern is neutral to slightly negative. For bigger storm you want to see this go more negative earlier. Two factors that can cause that to happen which we will have to watch closely are the sharpness and strength of the northern energy diving into the pattern, the strength of the western Atlantic ridge, and the speed of energy coming in from the southern jet stream. If these end up behaving differently than currently modeled then we can see a closer to the coast storm. Ideally you want to see southern energy getting out more ahead of the northern energy and it having a sharper track to move up. It is a big balancing act which needs to align perfectly. 

We will watch this closely all week to see if it trends more favorable. For now, I would say expect the chance of light snow Friday into this Weekend with minor accumulations possible for most areas. A few impulses of energy and possible a weak low pressure system from Canada (clipper) will continue to rotate this the region as the weekend progressing causing snow showers...

The period that has me more interested is the middle of next week...

I will comment on this more as the week progresses but we have a chance here that the southern jet stream energy may eject out ahead of an approaching northern jet stream disturbance which can cause a storm to develop and come right up the coast. Especially considering the jet stream will be blocked off in the Atlantic. We will have to watch this very closely. 


That's all for now I will have daily posts this week to track any evolution in Friday's system along with speculation around the middle of next week.