The Post Christmas storm has been shown on the models as a storm that will move well to our west and be rain for the Middle Atlantic into the Northeast. I posted blog a few days ago arguing for the eastward shift starting with the blocking setting up that would prevent such a solution. Well the GFS has come around in a very big way and shows a big time snow storm for Philly on northward!
One of the reasons mentioned in the blog was the blocking that was very favorable for an East Coast Snow Storm. The blocking has a tendency to be weakened too quickly on the models. Another thing mentioned was the phase 2 MJO showing the trough in the Eastern US. The models have backed off the MJO intensity but the latest IR imagery clearly shows the tropical forcing setting up towards a phase 2 with convection increasing south of Sri Lanka and the rest of the Indian Ocean.
The EURO keeps the inland solution but look at the lack of blocking:
The GFS shows the block:
Canadian model lso shows the block:
Another bias of the European model might also be showing up and it is related to another factor that argues for the eastward shift. The active pacific will keep things moving and prevent a very deep trough that destroys the block. The Euro shows a cut off system in the PAC right off the West Coast that prevents the "kicker s/w" from being deeper and kicking the system further east. It is the only model that does this and has a tendency to do this.
The Euro ensembles show an eastward adjustment:
Ensemble support from the GFS is also showing up...notice the inland and warm solution is disappearing from the members below:
Alice, Until the development issues get modeled out which won't happen until after Fridays storm gets by its hard to say. Any statement as to precip type made right now would be a guess since just about all types could be argued if X Y and Z happens. If you read this blog long enough you see valid arguments made for all types. Since this is at the front end of a pattern change the uncertainty lingers longer.
12z gfs Georgia to Philly miller a remix. Great Lakes cutter is gone.
I'm on board for a significant snow event for Philly for this storm.
12z gfs shows rain to an EXTENDED period of snow as the storm hits the block and stops moving.
I fully expect to see this show up off shore within the next 2 days with a classic nor Easter. High pressure showed up in Quebec WAY east of lastnights 00z run. Being that high another 100-200 miles east and BAM.
He's just showing everyone this went from the Great Lakes to the coast. No one has a clue if where it's going to rain or snow. Those details won't be ironed out until Monday at the earliest... And even then that's still to early.
Mike: Great blogs and maps. A White Chritmas ? Hope it turns out like the movie and snow later in the week? What a bonanza of the white stuff for here in the Philly suburbs and other areas.Time will tell.Thanks for the info.