Hello ladies and gentleman, this is an update to my last blog, snow lovers will be happy. The NAO is crashing and the AO is quite negative as well. The write-up that I did in my last blog mentioned the possibility of a significant event on or around the 27th. The reasons that this could well be the case were outlined within that blog, things have not changed regarding the time-frame or reasoning. Some of the things that will be mentioned within this blog were mentioned in the last, however, there will be additional information within this blog that will assist those new to the love of meteorology in understanding why this may be the case. The NAO falling sharply negative and the AO itself being quite negative are great signs, also, the PNA will be positive and the stj active. This, simply put means that the teleconnections are working well for a major event, (it should be known, as most of you probably already know, that everything teleconnection-wise could be perfect and we could see nothing, I myself have seen it happen many, many times. That said, I do not believe that will be the case this time and I will outline the reasons why). We are fairly far away from the 27th, but not that far, all things considered. So, that said, I will now explain in some detail why there is hope and a lot of it. The NAO falling sharply and the AO also being in a negative state around the time in question means several things. Number one, the NAO and AO will be very, very low around the time in question, but they will both be sharply rising, (according to the current forecast), right at the time the system in question is to be affecting our area. As many of you know, though some do not, the best time to look for a major snowstorm on the east coast is not when the NAO/AO bottoms out, but when it starts to quickly rise and that is precisely what is forecast to occur. If you check out the NAO/AO ensembles for that time frame, you will see that what is forecast to occur (which by the way is the "near best case scenario" for the Delaware Valley/mid-Atlantic and northeast, is what is forecast to occur and has consistently been forecast to for some time. Also, the polar vortex looks to be in good position. There will also be a wealth of cold air, over a large area, including ours, including much of the lower and mid troposphere. I will write another blog regarding this, most likely, tomorrow, Thank you for the kind attention you've given by taking time out of your lives to read this.
Good points John. It may be the first time this winter the signals are all in better coordination, along with available energy. The way this winter is going I wouldn't be surprised to get the most snow of the entire winter in early March!
I'm going to write up a new blog that explains why the strong system moving across the nation in what would appear to be an unfavorable track as far as snowfall for our area, will likely turn out well. I will explain why, from the 500 millibar heights, to the vertical velocity in the important parts of the troposphere as well as the skew t plots (soundings) and other reasons why the negative NAO and blocking will cause the system cutting across the nation to transfer it's energy to the coast where a baroclinic zone will set up and coastal cyclogenesis will likely take place.