The models have been very inconsistent lately, so the long range forecast has become very challenging. Even the short range forecast will soon be difficult, since it doesn't look like the models are getting a better grasp on the storm as they move closer. We'll start out with our teleconnections:
NAO:
Once again, I'm liking the trend, but as you can tell, the NAO likes to trend negative and then do a nice little flip for us that drives us all nuts! So we'll have to continue monitoring it very closely, but look for consistency, and not jump to any conclusions past 3-5 days out. RIGHT NOW, however, it looks like the NAO takes a dive. Keep in mind folks, the NAO does not tell us whether or not we will be able to get the cold and the snow. Rather it tells us whether or not we will be able to get blocking and sustained cold in our area. SO you CAN have the cold and the snow without the NAO. If you want the sustained cold and snow though, you really do want the NAO to take a dive...
PNA:
The PNA will take a dip negative, after being the only teleconnection to favor the cold and snow in our area. HOWEVER, we look out a little bit further, and it begins to trend back positive. Again though, I don't like looking at these models past 3-5 days out. Interesting to see however.
AO:
The AO has been EXTREMELY positive over the past few weeks, and has been doing some of the same fakes the NAO has been doing. Once again though, it looks like it will FINALLY be taking a dive over the next few days, which is certainly a good sign, and a start. We even see some models try and take it negative. OVERALL though, you can see, a lot of models remain positive, so the AO isn't really in our favor at this point.
REMEMBER: The teleconnections are our WILD CARDS. They do NOT dominate the overall pattern and set up, although they are able to help gear a pattern or set up a certain way. The weak east based La Nina will speak for itself soon enough, and as I have explained in other recent blogs, a lot of times that kind of set up can spell out a VERY cold and snowy Northeast.
Now to the short term and the models...
Hopefully all of you noticed the cool off today, and the temperatures will continue to dive through the night, and through the rest of the week. Most areas will be experiencing highs in the 40's come later in the week. That all ends though early next week, ahead of a complex system that will make its way across the country.
This is only one models depiction of the storm, but is a set up that I agree with for next week. We see temperatures rocket ahead of the system as it begins to move eastbound and strengthen.
The storm, while it may drop a decent snowfall for portions of the midwest, will only get interesting once it gets its act together... Here's the GFS's depiction again of the storm as it reaches the Northeast. You can see how quickly, and how strong, the cold air rushes in behind the storm, changing the heavy rain rain over to heavy wet snow into the PA and NY area.
As the storm reaches the coast, enough cold air is pulled in to change heavy rain over to heavy wet snow all the way over to the I-95 corridor...
Euro's depiction of the same storm around the same time...
Like I've said in the past... I do not believe this is a big, nor a widespread, snowstorm. I can see though, an area either in the interior, or even closer to the coast, picking up a very quick, wet, and heavy accumulating snowstorm. May not even be a lot of snow, but it may come down very fast and very hard. We'll have to watch this for sure over the next couple of days...
As we move ahead into the long range, we can see my "pattern changing storm" move through around the 8th-12th. The GFS has a rather weak storm that drops snow across the midwest and ohio valley, but doesn't do all too much to the Northeast. What it does do though, is make it COLD. Enough so, that it would be considered a pattern changer in my book, with a change to MUCH colder weather and better opportunities for snow.
Here's the Euro's idea around the same timeframe. Even less of a storm, but more aggressive with the cold.
Just a few more ideas that the GFS has that I like to throw around since we know it is OCCASIONALLY on spot with the long range forecast. Here's a possible system around the 14th with the cold air still in place.
Beyond that, we can see the 18z GFS keeps it simple with sustained cold all the way out to the 16th of December? Is this reasonable? Sure. Can I guarantee something like this to take place? Of course not... But it's certainly something to keep in mind!
To wrap it all up, we have a very difficult pattern ahead of us to forecast, and I will do my best to stay true and update often about all the latest changes. It may seem like I am relying heavily on just one run of the GFS, but that model explains best visually what I think will take place over the next few days and into the upcoming weeks. Don't worry... I am taking into account other models and factors! Enjoy the last day of meteorological Fall, and get ready for Winter tonight at 12 am!
-Scott P.
