Tuesday, January 20, 2015

Tuesday Morning: Major Storm Potential on the Boards for this Weekend

Well, we got a big one on the boards here guys. I will start off by saying I am still not completely sold that this turns up the coast, but I need to acknowledge the potential here. Let's start off by showing the surface map of last nights European for Saturday..

Yup, look at the pressure level of 974 that's a very powerful storm being projected for Saturday. In fact, if I look at the  European ensemble which basically takes this model and adjusts the inputs 52 times running 52 trials, 41 of those 52 trials have a low pressure system that is below 980. As a reminder anything below 990 is considered a powerful storm to me. 

If we took this verbatim, it would mean majors snows for south the south NJ and Baltimore Washington area.  I may add that almost every model is showing this storm and mostly all of them have this similar track. None of the models are turning this up the coast which means north Jersey, NYC, Boston ect. stay out of heavy snow. I hate to say it, but I think that is a believable outcome. The reason once again comes down to the pattern ahead of the storm and yes once again the -NAO.

Now it is possible to get a major storm without a -NAO, the probability is just lower. Without this pattern in place (high pressure over Greenland) the pattern tends to be more progressive. To get the big hit you need the timing to be perfect between the northern and southern jet streams merging. Thus, that is the case here. We need to depend on a very steep ridge out west helping the chances that the two disturbances combine.

Here is a simple view of this..

Basically what you see above is the jet stream rising to the west shown by the black line. This causes the jet stream to sink over the east. Within the jet stream there are two pieces of energy. This storm comes down to the timing on when they combine. If they combine earlier the storm is more west, later the storm is more out to sea. I will note that there is a slight negative NAO just before this storm comes in so we have a marginal pattern not a great pattern ahead of this storm threat. 

In any event, we need to keep an eye on this. Even though I am favoring a track more off shore if the timing is perfect we can have a major storm turn up the coast that is likely to have very low pressure and high wind. I will keep you guys updated daily on this. 

So lets move on to early next week were we are faced with yet another snow threat. 

This is for Tuesday into Wednesday and its been showing up on the model for a while now. What is so impressive about this set up is the size of the trough over the east. What I mean by that is the jet stream sinks very far south which means if we get phasing to occur we can have a bomb of a storm. We are far off but it is a very impressive set up. We will hone in on this as well as the days go on. 

Oh yes by the way there is a small snow event (clipper system) that will effect some parts of the area Wednesday..

As I said yesterday, I am not expecting much from this and any accumulations over an inch should be kept to the areas where you see the blue. Baltimore/Washington this can be a nice few inches for you. 

So bottom line guys we might have a pattern that wants to finally deliver some snow. Snow lovers do not get too excited yet, just know we got another shot here. In the best case scenario we can have a lot of snow on the ground by this time next week. Worst case scenario we have nothing. 

More later. 

PS one of the worst model's out there the Navy model has been the most consistent with a big hit on the weekend. This is the worst case scenario..

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