Saturday: Major Winter Storm Gaining Traction for Wednesday, Light Snow Monday

*Major Winter Storm to Potentially Impact the Region on Wednesday*

<<<<<<Update- 5PM Video Discussion, see below:>>>>>>

Good morning. A lot to talk about today as I am starting to hone in on a potential major winter storm for Wednesday into Thursday. I also am watching a smaller snow threat for areas to the NW on Monday.

Summary:

• Mild conditions this weekend transition to stormy conditions Monday as a cold front approaches the region
• Low pressure will develop along this front and  snow can breakout in areas like NW NJ, southern NE and NE PA on Monday.
• This is not the main storm threat but we can see a few inches in areas to the NW

• Very cold air then moves into the area on Tuesday ahead of a approaching large storm system

• This storm system will approach the region on Wednesday and has the potential to be a Major Winter Storm for many across the region through Thursday
• Best probability at this time for accumulating snowfall would be central NJ into Southern New England
• Without going into specifics this is the storm that has potential to deliver 12"+ to some

• This storm is by no means locked in but it is the strongest signal I have seen in a few years.
• Confidence is moderate at this time
• By Sunday night we should be able to get more specific on impacts

So as you can see, confidence is starting to increase. Every major model suite is now showing the chance of a signifigant winter storm. A word of caution, there is still a possibility the storm can trend weaker than currently modeled. This is why I will be cautious and not go into detailed accumulations till Sunday night.

In any event, I need to show you something so here are my impact maps for Monday's potential light snow event and the main event on Wednesday...

As you can see two systems to deal with here.

The Monday system will not have a lot of cold air to work with so if the precipitation aligns perfectly along the front, the higher elevations of NW NJ, NE PA, and southern New England can see a few inches of snow. I would not expect much snow elsewhere.

Here is a model projections for Monday...

Again, if this aligns perfectly we can see snow breakout but I would not expect much accumulation in any lower elevation areas despite what you see above.

Moving on, very cold air then moves in on Tuesday night ahead of the main storm system...

This is quite exciting as true cold air is an essential ingredient to a major storm system. I will note that Monday's storm trending stronger helps reinforce this cold air in its wake. It is all connected!

The reason we have this cold air arriving and locked in is due to the upper level pattern I have been discussing last few days which will lock in high pressure (the source of the cold air) seen below...

Again this is a classic look for a big storm and at the surface the models are responding. The loop below is the gfs ensemble model. I cherry picked this model because it closes represents my current thinking on how this storm evolves...

As you can see an amped up major storm system is being show on the models. If this came to fruition it would be largest winter storm for the region in two years and the largest December storm in many years.

So what would need to occur for this storm not to materialize?

At this time my focus would be on the big disturbance that will be seeding this storm seen below. The other parts of the upper air pattern I think are going to stay pretty stable which means if this storm fizzled out it would be due to the energy you see below getting strung out and not consolidating enough...

The less concentrated the energy is, the less likely a larger storm would develop. It still would be likely we see some impact however even in the "bust" case. Not my forecast at this time.

So there you go. Stay tuned I will be updating frequently on this blog and on twitter @weatherwilly.