18z Models 12/1/10

[LetItSnowInPhilly]

Looks pretty different out was already at 36.

[tombo82685]

out to hr 42, shortwave is stronger down to sub 1008 low, while 12z was sub 1012

[tombo82685]

looks like its a bit more amplified at hr 45, anyone else think so?

[Dsnowx53]

looks like its a bit more amplified at hr 45, anyone else think so?

I definitely agree. More potent and more amplified. Probably won't be enough, though.

[tombo82685]

by hr 48, definitely stronger and digging more compared to 12z

[Dsnowx53]

What I don't like, though, is that there really aren't any trends with the ULL.

[tombo82685]

What I don't like, though, is that there really aren't any trends with the ULL.

the one parked over the northeast im assuming?

[tombo82685]

hr 54 continues to be more amped up than 12z

[Dsnowx53]

There does appear to be a tad less vorticity out to the east, implying that perhaps the ULL is a bit weaker. It's nothing too drastic, though, so this run will probably just be a baby step in the right direction.

[tombo82685]

There does appear to be a tad less vorticity out to the east, implying that perhaps the ULL is a bit weaker. It's nothing too drastic, though, so this run will probably just be a baby step in the right direction.

yep its not as robust as 12z, while the shortwave is stronger.

[Dsnowx53]

yep its not as robust as 12z, while the shortwave is stronger.

Yeah, the shortwave is definitely a lot stronger.

[tombo82685]

hr 60 looks like a 1008 pressure over southern iowa

[tombo82685]

hr 69 has a 1012 low over lexington, ky

[TomieV]

thanks for the updates

[tombo82685]

hr 72 sub 1012 over eastern ky

[tombo82685]

gfs looks a lot like the gem, brings lgt precip just about to balt at hr 81

[earthlight]

Very impressive trend with the shortwave, the surface is a bit lacking. I'd be pretty excited regardless with that trend if I was in the DC proper.

http://www.meteo.psu.edu/~gadomski/AVN_18z/f72.gif

[tombo82685]

not gonna make it this run, hr 84 has a 1004 low just off hatteras, and moving ene, i would watch out sne, this may track close to them...all in all some good improvement.

[BaltimoreWxGuy]

Seems a bit further north than 12Z...too bad it weakens from 1008 to 1012 but thats what clippers do as they come down generally...The hope is that it would be far enough north, hit the VA caps and explode and get pulled northward...Wishful thinking

[Dsnowx53]

The trends were obviously very good on this run.

Now that being said, I'm afraid that we're just in the wrong spot. The initial clipper impulse might give 3-6" snows to DC proper, but then by the time the ULL captures it and hooks it back, it'll be too late for us, and SNE might cash in.

Anyone else feel the same way?

[tombo82685]

The trends were obviously very good on this run.

Now that being said, I'm afraid that we're just in the wrong spot. The initial clipper impulse might give 3-6" snows to DC proper, but then by the time the ULL captures it and hooks it back, it'll be too late for us, and SNE might cash in.

Anyone else feel the same way?

thats most likely what will happen. Unless it digs big time and phases a lot quicker, the clipper is the best shot of snow. The coastal would be for sne

[earthlight]

Very impressive trend towards a more robust shortwave over the past 24 hours. Basically everything has trended here--the ridge out west is stronger, the shortwave itself is more robust, the ridge axis and wavelength is more favorable between the shortwave and the ULL, and the ULL itself is weaker and further north.

00z GFS last night

http://www.meteo.psu.edu/~gadomski/AVN_0z/f90.gif

18z GFS today

http://www.meteo.psu.edu/~gadomski/AVN_18z/f72.gif

[earthlight]

The trends were obviously very good on this run.

Now that being said, I'm afraid that we're just in the wrong spot. The initial clipper impulse might give 3-6" snows to DC proper, but then by the time the ULL captures it and hooks it back, it'll be too late for us, and SNE might cash in.

Anyone else feel the same way?

Absolutely correct

[Dsnowx53]

Absolutely correct

Even when the Euro was going bonkers a few days ago, that result is pretty much what it showed, only to a larger extent. It gave DC like 4-7" of snow, then crushed E LI and E SNE, and only gave us a couple of inches.

I just find it hard to believe that we're going to have enough trending to get a BETTER solution than what that Euro run showed a few days ago. We definitely have room for improvement to that very solution, but we'd have to have some pretty large-scale changes for us to get in the act for significant snows, and I think time might be running out for that.

[jrodd321]

I say this is in an improvement from 12z today..

12z

18z

[eduggs]

The trends were obviously very good on this run.

Now that being said, I'm afraid that we're just in the wrong spot. The initial clipper impulse might give 3-6" snows to DC proper, but then by the time the ULL captures it and hooks it back, it'll be too late for us, and SNE might cash in.

Anyone else feel the same way?

Exactly. This is not the usual case where an approaching s/w can just tilt the flow and send a surface low up along the coast and everybody wins. For our area, the upstream trof HAS to move out of the way.

[tombo82685]

for our area, we should be tracking the clipper, the coastal imho will not affect us, unless drastic changes occur in the strength of the shortwave and the vortex

[tombo82685]

2nd storm is crushed like an empty beer can

[earthlight]

The important features are all here on the GFS this afternoon and just a quick glance at the model shows the problems with this setup at our latitude. We can learn alot from watching the guidance and this piece of guidance is telling us something as they all are. The image below shows the 18z GFS at 54 hours and I have marked the important features. First of all, we can see our shortwave of interest (which is probably the most important feature). This feature has trended stronger over the past few days as it has moved into better data assimilation areas in the Pacific. Secondly, we can see the upper level low and vortex over the Northeast United States. Not only is this feature large, but it has a ton of confluence associated with it and a northwest flow aloft. You can view the northwest winds aloft at most levels by looking at the NCEP or PSU Ewall maps which show the wind barbs and direction. Third, we see the ridge axis which has built in between the two features discussed (not bad wavelength separation here, if you live in the Mid-Atlantic). This ridge axis was not here last night on the 00z guidance suite of the GFS, as it was weaker with the shortwave initially and did not allow the feature to dig. Finally, we can see the ridge building out west, moreso than last nights guidance as well, which could help the feature to ampify. That being said, this feature has very little space to amplify, and really has nowhere to go in the pattern. The northwest flow aloft means this feature is going to dive southeast. The trend towards a stronger shortwave is good for the Mid Atlantic as it could allow for more ridging ahead of the feature, and slightly more amplification and a more developed precipitation shield which would otherwise be mundane. Still, the ULL is just way too close for us to expect anything of significant in our area. Even if the ECMWF from last night 00z was correct, the phase would occur as the ULL dropped into the system, which means the system would swing off the coast, with the confluence backing into our area once again as the system deepened, and then the surface low would be tugged towards the ULL towards the Gulf of Maine with a cold conveyer belt developing off the shores of New England. Basically, this synoptic setup as advertised is not favorable for frozen precipitation in our area at all--so I suggest that if we don't see any significant changes we begin to turn our attention to the not so distant future setups and potential.

[tombo82685]

vast difference between 12z euro and 18z gfs. Gfs still has under the vortex while the euro began the warmup....