NYC/PHL December 24-27 Potential - Part 2

[tombo82685]

just comparing hr 60 on the gem to the hr 72 on the gem 12z, looks like the s/w is more amplified on 0z

[jm1220]

I'm still in the "equal chances of a hit vs. miss" camp, maybe more in the miss camp as of now. I'm definitely not in the overphased inland camp. There's just so much chaos between northern stream shortwaves, the southern stream, and the influence of the ridge out west. I think that a sharp western ridge will increase the chance of a stronger northern stream wave phasing with the southern vort, but as baroclinic mentioned, if there's no equal momentum from a PV to swing it down, it might be for naught. It does seem curious still how the GFS dampens out the southern wave to nothing past 96 hours and dampens the whole trough out. So much needs to go right for this to happen and not get booted east, that it's almost impossible to make any kind of call without all the relevant pieces sampled on land. It wouldn't surprise me if we saw more violent model swings over the next 1-2 days before finally locking into a solution. I think it's either a major slam, or a complete whiff out to sea featuring nothing but thick cirrus. I was never a big fan of the "bowling ball" theory after the northern stream and confluence began looking so prominent on the models.

[Yorkpa25]

I can wait for euro. Other models are handling the s/w pretty well, they seem to be playing catch up to the euro. Hopefully euro holds steady, if not, the trend will not be our friend. It is still fairly early!

[Isotherm]

Take a look at the differences b/t the 00z GFS and the 12z Euro valid 12z Sunday morning. Note the HUGE difference in heights along the east coast, due in part to the earlier phasing/close off at H5 w/ the ECMWF but also check out the 50-50 low position. On the Euro the 50-50 is definitely a good bit further north which allows heights to rise more easily along the EC and consequently a more negatively tilted trough. We'll see tonight if the Euro holds on, but there are some potential big problems on the map here.

I think we need to see the confluence move out a bit faster w/ the GFS, the northern energy needs to be a little quicker as well. We need all the help we can get.

[mattinpa]

It just sounds like grasping at straws at this point because people are getting nervous. If the Euro looks bad what will people blame that on?

People tend to get nervous because besides last year, big storms rarely turn out for us. That's understandable. But it's still 5 days away.

[ace0927]

Wow, now I can hardly wait to see the euro.

the GGEM is out to 60 and its pretty much a carbon copy of the 12Z run at 72 hrs

[KEITH L.I]

It just sounds like grasping at straws at this point because people are getting nervous. If the Euro looks bad what will people blame that on?

they will wonder why Euro is showing bombs and then taking it away..I would start to have doubts about the model this year

[Stormlover74]

If the Euro doesn't hold steady the only hope is we still a day or two for things to change before completely giving up since it is still more than 4 days away. But it would be very discouraging to have little to no model support

I can wait for euro. Other models are handling the s/w pretty well, they seem to be playing catch up to the euro. Hopefully euro holds steady, if not, the trend will not be our friend. It is still fairly early!

[eduggs]

Trends tonight = Once again the good EURO runs appear to have been fool's gold.

This could be a tough night.

None of the previous misses have switched camps. And now we have to hold onto our hits just to maintain status quo so to speak. And it's not like the Euro and GGEM looked so much better than the GFS or UK through 3.5 days. So when we roll the dice again with those setups we could easily miss across the board. That wouldn't mean this is over... just that we're in worse shape than we thought.

[ace0927]

just comparing hr 60 on the gem to the hr 72 on the gem 12z, looks like the s/w is more amplified on 0z

the ridge is more amped up in the west, that is clear now that I really look at it.

[Rtd208]

While to verdict is still out on this one, I will say this, it will be ashame if we miss this storm opportunity.

[tombo82685]

they just said on the radio show the 60 hr 0z gem is slower than the 12z gem

[ace0927]

they just said on the radio show the 60 hr 0z gem is slower than the 12z gem

negligible differences in terms of timing between the two. maybe 50-75 miles....

[NorEaster27]

DT on the radio show seems wayyyyy too confident...for a storm 5+ days away with most models showing this OTS.... We saw this scenario already this past weeknd when the Euro was shoiwng a huge hit. This pattern is not THAT much different. BIG 50/50 low BIG confluence and tricky phasing if at all.

[ace0927]

at 72 vs 84 on the 12Z there are now some differences on the h5 over the tenn/ohio valley's....i dont think its going negative as quick....i could be wrong. the graphics on the site suck

EDIT- it also appears as if the huge 50/50 is FURTHER NE on this run thru 72 hours

[tombo82685]

here is the hr 108 of the gem i believe this is the correct one

[SteveB]

GFS ensembles are considerably farther North than the GFS ops

[Analog96]

DT on the radio show seems wayyyyy too confident...for a storm 5+ days away with most models showing this OTS.... We saw this scenario already this past weeknd when the Euro was shoiwng a huge hit. This pattern is not THAT much different. BIG 50/50 low BIG confluence and tricky phasing if at all.

Except that DT was never that confident for the last one.

[NortheastPAWx]

here is the hr 108 of the gem i believe this is the correct one

No, I think that's 0z/21:

hr96 = 0z/25

hr72 = 0z/24

hr48 = 0z/23

hr24 = 0z/22

hr0 = 0z/21

[Chris L]

DT on the radio show seems wayyyyy too confident...for a storm 5+ days away with most models showing this OTS.... We saw this scenario already this past weeknd when the Euro was shoiwng a huge hit. This pattern is not THAT much different. BIG 50/50 low BIG confluence and tricky phasing if at all.

DT has been doing this longer than we have been born; and he probably has forgotten more than we will know about East Coast Snowstorms...

Anyway, I am not too concerned about the GFS because given its history with east coast snowstorms, it has often struggled (in major ones rather signifcantly). But, we must keep every option on the table.

[SACRUS]

hit crtl f5 its correct and looks a bit east

[Manny]

DT on the radio show seems wayyyyy too confident...for a storm 5+ days away with most models showing this OTS.... We saw this scenario already this past weeknd when the Euro was shoiwng a huge hit. This pattern is not THAT much different. BIG 50/50 low BIG confluence and tricky phasing if at all.

We're at the same juncture we were at 12z today. If GGEM and Euro hold on, then once again it's 12z today all over again. There are obvious differences with the GFS/UK solution slower and looking more like the Euro, with a phase/no phase job potential.

[CheesyPoofs]

No, I think that's 0z/21:

hr96 = 0z/25

hr72 = 0z/24

hr48 = 0z/23

hr24 = 0z/22

hr0 = 0z/21

It's todays run (0z 12/22)...108 hours is 12z Sunday

[NortheastPAWx]

It's todays run (0z 12/22)...108 hours is 12z Sunday

OK when I first saw it it had hr108 as 12z/25.

[ace0927]

GGEM at 120 is mostly a miss to the east

[jm1220]

Take a look at the differences b/t the 00z GFS and the 12z Euro valid 12z Sunday morning. Note the HUGE difference in heights along the east coast, due in part to the earlier phasing/close off at H5 w/ the ECMWF but also check out the 50-50 low position. On the Euro the 50-50 is definitely a good bit further north which allows heights to rise more easily along the EC and consequently a more negatively tilted trough. We'll see tonight if the Euro holds on, but there are some potential big problems on the map here.

I think we need to see the confluence move out a bit faster w/ the GFS, the northern energy needs to be a little quicker as well. We need all the help we can get.

I don't think the difference between the runs has to do with the 50-50 as much. The 50-50 isn't really that dramatically different between both runs. The differences stem from the dampening out of the southern stream energy (which might be the GFS bias at work at it tends to underemphasize southern stream influence, I mean that wave just DISAPPEARS in 6 hours on the 0z run), the speed of that wave, and the strength of the polar vortex in Canada. The ridge is also slightly stronger still on the Euro. I think that if the southern wave stays intact enough and interacts with enough of the northern stream, it'll develop plenty enough of a storm in time to slam us.

[Isotherm]

OK when I first saw it it had hr108 as 12z/25.

Never doubt tombo, he's on his game.

[jm1220]

GFS ensembles are considerably farther North than the GFS ops

That's probably a red flag that the run missed something the other members picked up on to an extent. My guess is that it destroyed the southern stream wave too quickly.

[NortheastPAWx]

Damn, now the GGEM is in the miss camp...never fails with the radio show does it.

[mattinpa]

Canadian is east of the Euro but not as east as the GFS.