NYC/PHL December 24-27 Potential Part 3

[Isotherm]

Phase and capture still a bit too late for us but favorable trending at H5 compared to 18z.

[Allsnow]

Why is the low further west around NC.....pretty much has it over hse.......18z was further east....but at out latitude it looks further east then 18z

[weathercoins]

Every run it gets slightly better. if euro holds up in 2.5 hours I bet tv mets finally start the hyping.

[tombo82685]

hr 108 storm is pulling awy just some left over lgt precip over sne

[bluehens]

Is it me or is the timing here signficantly faster than the Euro......seems like storm is over for PHL by 0z Monday whereas Euro had an all day event on Monday.

[Dsnowx53]

Everyone thought this run looked better, but it really never did. Since it was faster, it of course "appeared" more amplified, since everything was occurring faster with the amplification, but as time went on, the fact that the 18z GFS was slower allowed it to dig more and amplify more, and thus actually be a better solution than the 00z GFS.

[am19psu]

Wrong

In GFS-World, it's not really a trend at all. It's faster, but synoptically, hardly any difference

[bluehens]

Results at worst seemed on par with 18z......100 miles west and we're building very big snowmen

[jm1220]

Since the S/W is faster on this run, it takes longer for it to really phase and capture, and by the time it does it's too late for most outside of Cape Cod. It also shears the whole system out and causes the whole thing to stay weak until the northern energy finally catches it.

The key tonight I think is too see how fast the Euro sends out the energy. If it noticeably speeds up tonight, it might be a sign of it caving into the more offshore models.

[Sunny and Warm]

Normally I wouldn't be concerned but considering we have the s/w onshore and that the first two models with the data have unfavorable trends....

Actually they both trended toward the Euro, just not enough for your liking (or mine). The models are still moving west, if ever so slightly. At this range, the NAM is a throwaway. The s/w is not entirely onshore and sampled, so if 12z tomorrow shows the faster solution, then I'd agree with you that a coastal scraper may ultimately be the correct solution. You just can't say that at the moment.

[Dsnowx53]

nope- a step back from 18Z

Yup. I don't like this run at all.

[weatherweather]

I dont think the 0z nam and 0z gfs can really be compared hr for hr with prev runs. They seem to be spittin out almost a diff solution with faster evolution, faster phasing but less digging when compared to the euro. Its really hard to say if this is better or worse.

[NittanyWx]

The progressive nature of this run was due to the weakening of the southern stream shortwave (once again).

[mattinpa]

Radio show says there are improvements, but the trof is too wide this run.

[famartin]

Since the S/W is faster on this run, it takes longer for it to really phase and capture, and by the time it does it's too late for most outside of Cape Cod. It also shears the whole system out and causes the whole thing to stay weak until the northern energy finally catches it.

The key tonight I think is too see how fast the Euro sends out the energy. If it noticeably speeds up tonight, it might be a sign of it caving into the more offshore models.

Yes

[NortheastPAWx]

Wrong, why are you guys posting this crap. There is more ridging ahead of the system at 500mb. Look at the upper air, not the surface at this point folks.

It doesn't matter, it's all too fast.

[NittanyWx]

In GFS-World, it's not really a trend at all. It's faster, but synoptically, hardly any difference

The southern stream is significantly weaker compared to the Euro. GFS has been consistent (by its own standards) with that.

[Collegestudent11]

The southern stream is significantly weaker compared to the Euro. GFS has been consistent with that.

Why is that? The southern stream is onshore now is it not?

[Isotherm]

Since the S/W is faster on this run, it takes longer for it to really phase and capture, and by the time it does it's too late for most outside of Cape Cod. It also shears the whole system out and causes the whole thing to stay weak until the northern energy finally catches it.

The key tonight I think is too see how fast the Euro sends out the energy. If it noticeably speeds up tonight, it might be a sign of it caving into the more offshore models.

Yeah the faster southern stream s/w is the reason for the later phase and capture. Had snow breaking out Christmas night across the sern mid atlantic. We need the slower solution to allow the northern s/w to catch up and phase in time. H5 is slightly better in terms of the height rise on the EC and sharpness of the trough, but the timing is problematic as you noted.

[am19psu]

The southern stream is significantly weaker compared to the Euro. GFS has been consistent with that.

Oh sure, there are still significant differences between the two models, but, synoptically, I didn't see anything other than speed diffs between 12z and 0z in the GFS. Did you, since I'm watching the football game too and I wasn't looking at every minute detail?

[Zir0b]

not liking the trend with the s/w on shore. nam/gfs both in consensus about speeding it up with the new RAOB data, i expect euro to follow this new development

[mattinpa]

not liking the trend with the s/w on shore. nam/gfs both in consensus about speeding it up with the new RAOB data, i expect euro to follow this new development

Or maybe the Euro will hold as it has done for about 6 runs. It doesn't often hold for that long. You can get the data but not always do the right thing with it.

[Dsnowx53]

Yeah the faster southern stream s/w is the reason for the later phase and capture. Had snow breaking out Christmas night across the sern mid atlantic. We need the slower solution to allow the northern s/w to catch up and phase in time. H5 is slightly better in terms of the height rise on the EC and sharpness of the trough, but the timing is problematic as you noted.

The reason, though, why the height rise was better was because the storm was faster, so there was an earlier amplifying process since the southern stream made the initial "phase" with the northern stream earlier (which is when the southern stream vort kind of got dampened out into the northern stream complex)...as you looped out further in time, the fact that the 18z GFS was slower allowed it to amplify more, so it caught up, and eventually surpassed the 00z in amplification, so the 18z GFS solution was better. That's how I see it..

[greg ralls]

There is nothing to be overly concerned about the 0Z runs yet - just listen to the radio show. In fact, they're saying it's a step in the right direction.

[weatherweather]

The real only negativity is the broadness of the trough at 500mb. Other than that, its diggin more and getting ready to go negative faster.

[famartin]

To think a little positively (to possibly all our detriments ), those who point out the shortwave isn't completely onshore are correct. It will be better sampled for the 12Z run. If we don't start to see good trends in the GFS by then, I think we might be in trouble...

[jm1220]

Yeah the faster southern stream s/w is the reason for the later phase and capture. Had snow breaking out Christmas night across the sern mid atlantic. We need the slower solution to allow the northern s/w to catch up and phase in time. H5 is slightly better in terms of the height rise on the EC and sharpness of the trough, but the timing is problematic as you noted.

Looks like there's lots of energy to be had that will eventually spin up a major storm, and SE NE gets blasted on this run pretty good, but it won't do us any good if the storm stays sheared out until it's already past our longitude. Hopefully the Euro holds firm in terms of its timing of this southern feature, I think that if it phases near the timeframe and location the Euro has, we should be awesome. We might even have a little wiggle room in that regard since the snow gets well west into PA on the last few Euro runs. I also think it has to be more than just the Euro hold-back-energy bias at play since it's had the SAME outcome for 5 runs now. The GFS often has a too quick/overemphasize front side energy bias as well, so I'm not that worried yet.

[KEITH L.I]

believe me,tonights GFS run is not the final solutiion..100 miles to the west we're in business..and the Euro and it's ensembles are a go

[hazwoper]

oh well on to the Euro. When do the GFS ens. come out?

[jm1220]

not liking the trend with the s/w on shore. nam/gfs both in consensus about speeding it up with the new RAOB data, i expect euro to follow this new development

12z tomorrow will probably be the most crucial, since all the main players will be ashore and sampled well. There was even some missing data near the center of the S/W off southern California tonight.