What about the 15th and 16th?

 Today we have a trough dropping in out of Canada and moving across the great lakes into the Northeast and Middle Atlantic. With the trough is coming some cold air. As has been the case for a while we're gonna see a few clippers move through this week. The trough and the pattern this week is setting a stage for a few possible storms to impact our region. 

850MB temperature anomaly from the GFS courtesy of tropical tidbit

The 500MB Vorticity And height chart Courtesy of tropical tidbits

Wednesday's chart is showing 2 pieces of energy one in the northern stream dropping across the plains and another in the southern stream. Both of these will be critical as to what happens for Thursday and Friday. How these 2 interact will be a major player and if the mid Atlantic into new England sees a major snowstorm. Right now the question is Will the northern pc of energy outrun the southern pc of energy or will they end up phasing?

Before we go further I want to talk about the madden Julian oscillation.

Madden Julian oscillation

I show the MJO diagram a lot but it's been quite a while since I explained how to read it. So here's a quick refresher that will go over the basics.

The MJO is a massive wave of air and thunderstorms that travels eastward and takes 30 to 60 days to travel around the world.

The MJO Is divided into 8 phases. Each of these phases is based on the location of the MJO. When looking at the diagram think as if you are looking down at the globe and at the center of the diagram is the north pole. On the diagram we see various colors of lines.

The red line Is the 0-5 day, the blue line is the 6-10 day and the purple line is the 11 day and beyond. The closer the lines are to the center circle The weaker MJO is considered The further away these lines are from the center circle the stronger the MJO is considered. When the lines are within the center circle this is considered the null phase. Sometimes it's called the circle of death. When the lines are within the null phase; the MJO is weak and not exerting much in the way of influence on the patten weather

Specific weather patterns and events in certain parts of the globe can be tied to the individual MIO phase depending on the  time of year. During the winter, phase 6 is not really considered a warm phase here on the East Coast as we typically see ridging out west and a trough into the Great Lakes. Phase 7, 8 into phase 1 are considered cold phases during the winter. Phases 7 and 8 are typically correlated with colder than average temperatures here in the Northeast and Middle Atlantic.

Why is the MJO important when we look at the possibilities of a snowstorm impacting parts of the East Coast on the 15th and 16th? When we looked at the diagram Above We see that the MJO on the 15th is going to be in phase 6. While phase 6 does indicate  we will have some cold air in the region; it's not necessarily the best phase to set up a pattern for a snowstorm here in the Northeast and northern Middle Atlantic. But when we look back at the diagram We can see that the MJO does quickly move into phase 7 and then phase 8 and 1. These phases   are much better signals for storminess as we move deeper into January and into February.

It's looking much more apparent that we're going to see these two areas of energy phase and that the trough is going to become negatively tilted. So a storm should be able to come up the coast.

Where the upper level low developed and sets up is going to be a big factor when it comes to the placement and behavior of the surface low that should be up around the Delmarvia  Peninsula. 

These images Courtesy of tropical tidbits show the upper level low setting up around the Carolinas into northern Georgia. Then it has the storm moving east and north just off the Mid Atlantic coast and south and east of Long Island.

Courtesy tropical tidbits

The GFS is showing a major snowstorm impacting the Middle Atlantic into southern New England and southeast New York State I-95 corridor. Bringing heavy snow to DC, Philadelphia, Baltimore, New York City into Boston. The ECMWF European has been showing the storm being further north than the GFS. Which would keep the heavier snow just north of the major cities. But starting last night and continuing today the euro is trending towards the GFS and it looks to be caving to what the GFS has been showing.

We don't have strong upstream blocking over Greenland. Remember the MJO looks to be in phase 6. So this would be a fast moving system and with the MJO in phase 6 the storm might be more fragmented and not as consolidated as we'd need for a major heavy snow event for the I-95 corridor. 

This is a look at how the forecast is coming together and some of the players on the field. While there's a chance for a major snowstorm in the Middle Atlantic and southern New England. Some of the teleconnections favor it not being as big a deal as the GFS is hinting at. So it could be more of a moderate event than not. Anyway this is how things look to me at the moment. One thing to keep in mind is that while the MJO in phase 6 is hinting at this being more of a moderate event doesn't mean that we can't have a major snow event with the MJO in phase 6. We will have to watch and see how things trend and how things look to come together as we move forward over the next few days.

We do have a shot at another snowstorm around the 18th to 20th But let's get through the event this week or at least get closer to the second event before we get much into that.

That's it have a great rest of your Sunday.