Well well the normally warmer NAM has not gotten into range of the Friday system and starts off with a rain to snow situation and no this is not a bit colder air...it's the first sign of Arctic air reaching the east coast.
The Canadian has been hinting at this for 6 straight models runs and even now the GFS is getting on board. Is this a big snow event ? no it's more of a pattern change that tells me the models are still evolving into a winter pattern very UNLIKE last winter.
Some forget just two winters ago we had the NAO and AO working well together and the year before it was El Nino on crack. I honestly think the two November snow events and Sandy gave everyone a false start to the the winter.
Climatology shows very little snow from NY to DC in December and well everyone wants to push past the climo numbers because many think the active November was the start of winter and it was not....it will start soon enough ya'll.
**** WORDS OF CAUTION ****
I don't care if it's the PNA NAO AO EL NINO PDO OPP GOP...these signals are only good for a two week period from today so if you think a signal is not going the right way it certainly DOES NOT mean this will be the case all winter.
You have to watch everything and how it teleconnects worldwide not one signal, not one model run, not even a few mild days in December will decide how January - March will play out. Relax we are in the 1st inning of the winter. Grab a beer and peanuts and enjoy the winter game ahead of you.
BLOG SONG ----BLURRY by Puddle of Mudd
Every thing's so blurry
And every model can be a fake And everybody's worried And everything is so unpredictable Preoccupied with a model I cannot forecast at all My whole world surrounds snow I stumble then I blog
You could be my pattern You could be my model You know that I'll protect you From all of the warm is seen I wonder what your doing? Imagine where you are? There's oceans in between storms But that's not very far
Can you take it all away Can you take it all away Well you shoved the PNA in my face This pain you gave to me Can you take it all away Can you take it all away Well you shoved it my face and now it's gonna change
Ok lets look at each model a little closer and see where I am leaning at this point.
Again, Rob, let's remind our weather enthusiasts here that the 540 thickness "red line" is the first line of guidance...it is possible to have rain or freezing precip north/west of the RED line and/or snow south/east of it. We have to look at the finer resolution critical thicknesses through 1000/850 and 850/700 layers.
I do also support the idea of back end snow on Friday as the cold air rushes in behind a departing storm. This is typical stuff for December with windy conditions and and flurries and snow showers blowing through the neighborhoods come weeks end.
I am still on board with my 16-26" of snow in my winter forecast. I see no reason at this early stage to change this.
I will be doing a blog later this afternoon or evening. The one thing I like seeing over the past week is a more active southern branch of the jet stream that is again reloading out in the pacific southwest of California... time this feature up with even modest cold air coming across Southeastern Canada we will be in serious snow business to the tune of 10"+ for the Mid-Atlantic points northbound.