NYC/PHL 12/21-12/27 Forecast Threats

[tombo82685]

heres hr 120 on the gem, low over northern alabama

[earthlight]

heres hr 120 on the gem, low over northern alabama

Closed H5 low coming in near the Great Lakes is an absolute beast.

[Collegestudent11]

Closed H5 low coming in near the Great Lakes is an absolute beast.

Would that be the northern stream that is supposed to interact with the s/w?

[tombo82685]

gem says im game

[earthlight]

Would that be the northern stream that is supposed to interact with the s/w?

You are correct. That feature is going to phase into the shortwave given the upper air pattern modeled by the Canadian at 120 hours, it's just a matter of when. The ridging ahead of the shortwave over the East Coast suggests this run will come north if the phase occurs soon enough.

[Zir0b]

ggem looks a bit better at h5 compared to 12z, lets see if it turns the corner

[earthlight]

Like clockwork, the phase occurs..the ridging does it's job, and the CMC makes us all smile. This pattern is a ticking time bomb.

[jrodd321]

Damn 144 is looking beastlyy

[SACRUS]

168

[eduggs]

heres the gem at hr 108, looks to be a little south of 12z

North vs. south can get confusing as you can have a situation where the s/w is sharper but the surface low is slower and further S or vice versa. Regardless, I think the s/w on the GEM is much improved over 12z.

[Collegestudent11]

I would figure since the Northern Vortex is over Canada right now, that it should be sampled correctly and would not be subject to rapid fluctuations.

[earthlight]

I would figure since the Northern Vortex is over Canada right now, that it should be sampled correctly and would not be subject to rapid fluctuations.

Another good point; and this is probably why we have seen little fluctuations in the guidance (thus far) compared to the last system. The shortwave coming out of the Pacific is basically coming straight off a ULL which is already sitting right off the coast. We don't have many major poor sampling issues to deal with here. The phase timing is going to become the serious issue over the next few days. But as far as I am concerned, the light is turned on for this threat...all systems are go for tracking this week.

[SACRUS]

Good to see the ggem has come around. Good trend

[Zir0b]

$20 says the 0z Euro will look more like the GGEM than the GFS

[earthlight]

Old....

Was wondering how the 992 goes to 1003 OTS.

Clear your cache or refresh. It's a 970mb surface low which looks to have passed directly over the 40/70 benchmark.

[SACRUS]

That's gotta be old run.

no its updated. You may beed to hit crtl - f5 to force a refresh. The ggwm maps have habbit of sticking

[earthlight]

The CMC closes H5 off with 520dm heights...unreal.

[gkrangers]

Clear your cache or refresh. It's a 970mb surface low which looks to have passed directly over the 40/70 benchmark.

People shouldn't direct link. That should be a rule for model threads... Makes them a lot more useful for historical purposes especially.

And yes, good to see the GGEM bomb.

[BL03]

that 144hr ggem map is what i thought the gfs would look like at 144hr after seeing hr 130,136... its good to see the ggem showing this. The h500 pattern favors this outcome imo...more than last storm.

[eduggs]

The GGEM was the last real suppressed hold out. And now it's showing a solid snowstorm for most of the coast. This also gives us some breathing room if a few other models miss in coming cycles.

[Zir0b]

Would love the see what GGEM does between 150-162

[gkrangers]

Would love the see what GGEM does between 150-162

Probably something like this:

[earthlight]

that 144hr ggem map is what i thought the gfs would look like at 144hr after seeing hr 130,136... its good to see the ggem showing this. The h500 pattern favors this outcome imo...more than last storm.

We'll get the GGEM maps through 180 hrs on eWall in about a half hour. Should be nice viewing.

[SACRUS]

Would love the see what GGEM does between 150-162

1:00 the 6-12 hour panels will be available.

[SnowGoose69]

This could be the GEM's normal bias having the lows too far west/warm ETC....so use caution for now....the Euro could very well resemble the GFS more.

[gkrangers]

This could be the GEM's normal bias having the lows too far west/warm ETC....so use caution for now....the Euro could very well resemble the GFS more.

Nothing wrong with that 120+ hours out.

[eduggs]

This could be the GEM's normal bias having the lows too far west/warm ETC....so use caution for now....the Euro could very well resemble the GFS more.

Could be. But then how do we explain its past few runs? And it's not like it's showing a mid/upper level solution that's entirely distinct from recent GFS/Euro runs. I think we have to take it at face value and add it to our mental weighted average.

[ace0927]

call me crazy- but this map has Jan 1996 written all over it.

gem says im game

[Zir0b]

call me crazy- but this map has Jan 1996 written all over it.

[earthlight]

Here's a good example of the modeling we are seeing and exactly how impressive it actually is. The synoptic setup is very favorable for snow in the Mid Atlantic. The shortwaves being sampled decently (not well, but decently) at this range lends credence to the models relative consistency so far through this period. The GFS aloft, which actually is suppressed (but not by much) has a very impressive upper air setup. The shortwave over the Central US is closed off--with a favorable ridge axis building ahead of it with the all important confluent flow over New England. The phasing northern stream shortwave is heading for the International Border. We are in a very, very good spot at this range. There's a long time to go..but it should be a fun few days coming up. Get your sleep now.