A little snowstorm for the I-95 corridor, then what?

 

I've been laying out the storm setup for the northern Middle Atlantic and the I-95 corridor into southern New England for several days. My thoughts on that haven't changed. In fact all of the models have come into a very good agreement that corresponds to what I've been talking about and saying. So if you want to know about my ideas and general accumulations You can go back to yesterday's post and read about them. Instead this post is going to talk about what comes next as far as the pattern!

A look at sea surface temperatures.

Image credit tropical tidbits.

Looking at the image a few things stand out, 1st thing we can see is the cool water anomalies across the eastern into central equatorial pacific.  So even though the La Nina is weakening it is still sticking around! The 2nd thing that stands out, is how warm the water temperature anomalies are in the Atlantic Basin. The 3rd thing that we can see is the water temperature anomalies in the North Pacific right into the Gulf of Alaska.

In the winter outlook and pattern update post since then. I've been talking about the ENSO and how the La Nina is going to be very weak this year and how it would be short lived. That is indeed what is occurring.

The North Pacific

Comparing the temperature anomalies Across the north pacific We can see The warm blob That we had in the fall And we saw some cooler water anomalies enter the Gulf of Alaska. But since then those cool SSTs in the Gulf have been warming back up. As I said in the winter outlook the temperature anomalies in the North Pacific Indicate a good chance for a weak polar vortex and arctic outbreaks working into the central and eastern United States.

September 11

November 16th

It's been cold no doubt about that in fact this is the coldest December the region has seen in several years.

Image credit prison group with Oregon state university

With the cold and the active pattern of back to back clippers; a large part of the region has been building a snow pack.

 

The deep snow pack across Canada is helping the cold air slide down the ridge into the northeast and middle Atlantic. By keeping it from modifying. The cold conditions and setup Have led to a fairly deep snow pack across Tug Hill (the Tug is really adding to that this weekend) along with the Adirondacks into the Greens and Whites. Other areas have a moderate snow pack. And then many areas have a light snow pack. With the I-95 corridor Seeing their 1st snowstorm of the season tonight and tomorrow The vast majority of the region will have seen snow before Christmas.

what about going forward?

Those very warm SST temperature anomalies in the north pacific are a strong indicator that we are not done with cold air intrusions going forward

Madden Julian oscillation

The MJO

The MJO has left phase 8 and is now moved into the neutral Circle.

The CFS

The ECMWF

 

So with it being in the neutral phase This would be a sign that temperatures will moderate over the next several days. But the euro and some of the other models are showing MJO migrating back out into phase 8 after the middle of the month heading towards the end of the month. If this is indeed the case; that would mean heading back into cold weather around Christmas and  likely into January. If all this sounds familiar it is because I've been saying this for the last few weeks.

Eastern Pacific Oscillation

EPO

The EPO Is currently negative But it is trending towards positive. But then the models have a trending negative as we get closer to Christmas.

The EPO is a very important teleconnection to watch Because it's an important driver of cold air for the East Coast. When the EPO is positive we tend to see the pattern send warm air into Canada. Which in turn directs warm air down into the United States. When the EPO is negative,  the exact opposite happens, We see higher pressures in the East Pacific which allows the pattern to send cold air in Canada down into the Eastern and Central United States.

Where the EPO looks to be uheading  is a strong signal for a pattern change as we get around Christmas. This supports what the MJO is hinting at for the end of December into January.

The Arctic Oscillation and North Atlantic Oscillation.

The AO and the NAO are very important as well. 

AO

When the AO is in the negative phase We tend to see the polar vortex stay weak. Looking at the arctic AO we can see it's been predominantly negative Since at least the middle of November During that time  the vortex has been very weak. This explains the Stratospheric warming events and arctic cold outbreaks across the region

NAO

When the NAO is negative we tend to see a better chance for phasing to occur between the northern and southern streams of the storm track. Over the last few weeks the NAO has been predominantly positive. This is the reason for the lack of phasing and partly the progressive nature of the pattern. 

Going forward over the next 10-14 days. Neither the AO or NAO support the idea of a lot of cold air over our region. The NAO does look to trend negative as we approach Christmas, But that remains to be seen. It's important to know that the EPO can override the phase of the NAO. So based on the idea of how the EPO looks to be trending and the idea that the MJOs is likely going to move back into phase 8 later in this month; is where I'm basing my idea of it getting colder towards the end of December into January.

If you've been reading my post you know we're going to be warming up. The warm up means that some will lose Most of your snow or all of it, over the next few over the next several days next week. If this occurs It could ruin some of y'alls prospects for snow on the ground for Christmas Day. Those with the deeper snow pack will likely hang on to enough snow to ensure snow on the ground for Christmas. Not to give false hope but there are signals in the pattern that suggest a possible storm around the time we get to into Christmas Eve and or Christmas Day. The models are suggesting and the teleconnections I've just gone over show that as we get near Christmas There is likely going to be a pattern change and we could see cold air moving back into the region. Does that mean a snowstorm for Christmas Eve or Christmas Day? Maybe! We will have to wait and see how the pattern and setup evolves over the next 10 days. Right now  it could go either way. But a chance is better than no chance.