NYC/PHL December 24-27 Potential Part 3

[tmagan]

By the way, the 06Z DGEX is out to see with barely any measurable precip in the Northeast.

[tombo82685]

hr 51 still has a closed low almost to the la/tx border...faster than the nam...northern stream looks slower to

[tombo82685]

hr 54 closed low over baton rouge...this looks a good bit better than the nam imho so far

[tombo82685]

sub 1016 low over the boot of la at hr 57...northern stream trying to dive in

[tombo82685]

hr 66 has a sub 1012 low over pennsecola....northern stream getting hung up, not truly diving straight into it

[baroclinic_instability]

Has potential...

[tmagan]

There are differences between the 06Z GFS and 06Z UKMET.

[tombo82685]

Has potential...

the northern stream just really lags and never goes fully neg tilted.

[tombo82685]

so basically now it looks like you want the speed of the shortwave shown here, but you need the northern energy to speed up a little more?

[weatherweather]

soooooooo close at90

[tombo82685]

soooooooo close at90

yea its wetter than 0z for nyc and phl

[mattinpa]

yea its wetter than 0z for nyc and phl

Good news then. Finally to bed. How did it look better without good phasing?

[Inudaw]

Soo....close...to a big hit. : (

The northern stream needs to dig into the southern stream more so than it did.... about 6 hours late... OR 50 to 100 miles to far north early on when the shortwave is crossing the deep south. ><:

I'd like the southern stream feature to be stronger......as it crosses the south to induce more ridging out ahead of it and to produce a stronger low initially along the gulf coast. Right now the low really does not get going till its in the Atlantic.

[tombo82685]

Good news then. Finally to bed. How did it look better without good phasing?

its basically the same track as 0z maybe hair further west. just need that northern stream a little more agressive.

[baroclinic_instability]

so basically now it looks like you want the speed of the shortwave shown here, but you need the northern energy to speed up a little more?

I don't know, honestly that almost looked as good as it can get. Would like to see the upper trough dig more into the Gulf, but I don't know if that can happen now. GFS is real close, but I brought this up in the 18Z model discussion...it could very well be the difference between model resolutions and their ability to model some of the very mesoscale forcings that will play a prominent role in cyclogenesis. ECMWF has the decided advantage in horizontal resolution (they are both spectral wave) over the GFS, even after the GFS upgrade.

[Voyager]

yea its wetter than 0z for nyc and phl

Good news then. Finally to bed. How did it look better without good phasing?

So far it still does nothing inland except perhaps a few flurries.

[atownwxwatcher]

I think an important thing that we are not exactly looking at here is that this is actually slower and more to the west despite the Northern Stream Lagging. In all honesty this now IMO would start to raise questions as to was the faster speed of the ECM a legit move or was it all due to lack of data of the ULL at 00z initialization?

I would imagine that the GFS means will come more west from 00z...and also interesting now to see the 12 Z ECM and see if it does slow down the Southern Stream S/W once again.

[tmagan]

It even brings P-type issues to the cape.

[Snowlover11]

well gfs did come southwest a bit, but still not good enough. Hopefully 12z runs are better and start telling us something.

[tombo82685]

I don't know, honestly that almost looked as good as it can get. Would like to see the upper trough dig more into the Gulf, but I don't know if that can happen now. GFS is real close, but I brought this up in the 18Z model discussion...it could very well be the difference between model resolutions and their ability to model some of the very mesoscale forcings that will play a prominent role in cyclogenesis. ECMWF has the decided advantage in horizontal resolution (they are both spectral wave) over the GFS, even after the GFS upgrade.

lol you need like a 50 mile shift maybe 25 mile and phl to nyc would be warning criteria snow... It just looked like the northern stream dove down then just stopped. Would a stronger s/w help this out?

[CooL]

Well this run supports the euro more than any other model imo..The ggem was not even close

[tombo82685]

I think an important thing that we are not exactly looking at here is that this is actually slower and more to the west despite the Northern Stream Lagging. In all honesty this now IMO would start to raise questions as to was the faster speed of the ECM a legit move or was it all due to lack of data of the ULL at 00z initialization?

I would imagine that the GFS means will come more west from 00z...and also interesting now to see the 12 Z ECM and see if it does slow down the Southern Stream S/W once again.

thats a very valid point. Both the nam and gfs slowed from 0z. But wasn;t the euro slower than all of these models. They could just be finding a middle point now.

[Voyager]

lol you need like a 50 mile shift maybe 25 mile and phl to nyc would be warning criteria snow... It just looked like the northern stream dove down then just stopped. Would a stronger s/w help this out?

Need about a 150 mile shift west.

[tombo82685]

alright im going to bed, hopefully the ens show some good stuff..

[baroclinic_instability]

lol you need like a 50 mile shift maybe 25 mile and phl to nyc would be warning criteria snow... It just looked like the northern stream dove down then just stopped. Would a stronger s/w help this out?

Yeah it is very close...really so close too hard to call. As you said, shift this 25 miles and it is lights out for Long Island. So many things to consider in a rapid cyclogenesis event...I hate to say it, but this will likely flip-flop all the way up to 24 hours or so...and everyone will be pulling their hair out with each run...but 6Z run was a good run since it shifted it W.

[lindywx]

Historically the GFS doesn't lock in a solution for the "Big Ones" until about 24 hours before the event so I like where we sit, at least from the eastern half of Jersey northeast through southern N.E. As far as areas further south, they still have a ways to go but they are still in the game too.

[SnowGoose69]

If you only showed someone the position of the GFS low at 102 they'd think it pounded NYC/LI/NJ at 90 and 96 but in reality that left hook its making results in those areas only seeing a glancing blow.

[A-L-E-X]

Historically the GFS doesn't lock in a solution for the "Big Ones" until about 24 hours before the event so I like where we sit, at least from the eastern half of Jersey northeast through southern N.E. As far as areas further south, they still have a ways to go but they are still in the game too.

gfs ensemble mean from 0z had about 0.5 qpf for western long island, so there is still some room for improvement, but its looking good.

[A-L-E-X]

If you only showed someone the position of the GFS low at 102 they'd think it pounded NYC/LI/NJ at 90 and 96 but in reality that left hook its making results in those areas only seeing a glancing blow.

Hopefully the ensemble mean will shift west once again. BTW what's causing it to make that extreme hook?

[SnowGoose69]

Hopefully the ensemble mean will shift west once again. BTW what's causing it to make that extreme hook?

The very late negative tilt at 500....thats why I've compared it a bit to the 1989 and 3/2/09 events in that the low after initially going NE off the coast turns and goes almost due north...most major east coast events the low has a heading of 020-060 the entire time.