Finally Some Snow in the Forecast...
We've been banking cold air left and right this week but for skiers and snow lovers this has been a big tease with all the snow falling lee of the lakes or in the Mountains. Well, that is about to change but only in a small way. On Friday, we shift from a cold air advection pattern to a warm air advection one and that means an increase in clouds on Friday and a period of snow Friday night. It won't be a lot, in fact, the big tease will continue as I am only expecting up to an inch. I will say this though, some models aren't spitting out anything Friday night...maybe a few flurries...but models notoriously underestimate warm air advection pattern and warmfrontal precip so I still think that coatings are likely. There is some question as to boundary layer temps sneaking up above freezing due to the southerly wind component but at this time I think that any mixing or change to rain should be confined to SE Mass.
On to the biggy late in the weekend and early next week. Up to this afternoon it seemed like a guarantee that this next big storm would be mainly rain but the 18Z GFS came in with a much colder solution and a true coastal storm presenting a mix to rain to snow event. As some of you have pointed out tonight, be very cautious with that run of the GFS. For one, the EURO has performed much better than the GFS and has been steady with its warmer solution to this point. Secondly, the initializing data for the 18Z and 6Z runs of the models is much more coarse than the 12Z and 00Z runs so the chances of an error are much higher.
Don't get me wrong, you can't totally discounting it, after all there will be a ton of vorticity out ahead of the shortwave capable of kicking up a new surface low along the East Coast but with the shortwave projected to cut off to our west due to downstream blocking a strong primary surface low will also develop to our west flooding the area with warm air out ahead of it and therefore providing us with a mainly rain event.
So that's the evening synopsis...it will be very interesting to see if this is a new trend developing.
