NYC/PHL December 24-27 Potential - Part 2

[Stormlover74]

It could be but if the GGEM is similar and the Euro trends to the east 50-100 miles than we'd have pretty good model consensus that this is largely a miss for the big cities with the coast cashing in on some good snows. Now if the GGEM trends west and the Euro holds then look out.

Look for it to trend even further towards the euro in terms of strength and track-- looks like the GFS just folded and all the GFS-huggers got really quiet.

[hazwoper]

UKMET came west

but not west enough, still good though

Yeah but that is a fairly substantial shift as well, is it not? Didn't see last nights, but was under the impression is was suppressed quite a bit like the GFS?

[am19psu]

This is very close to the track and intensity that I have been expecting as the final outcome as well. But what do you look for when you are looking for "errors?"

With a southern stream s/w digging that far south, there should have been more ridging than 0z and 6z showed due to stronger WAA. That should have slowed down the flow to allow a phase to happen over the CONUS, instead of offshore. This looks like a more "classical" solution.

[eduggs]

12GFS is entirely "northern stream" driven. The initial potent s/w currently near the west coast appears to completely dampen in the gulf of mexico. This might be the same evolution as the Euro, but it's more difficult to tell with 24hr panels instead of 6hr.

[Alpha5]

Yeah but that is a fairly substantial shift as well, is it not? Didn't see last nights, but was under the impression is was suppressed quite a bit like the GFS?

Yeah its a decent shift west, I remember last night it was way out there...

[psv88]

Yeah but that is a fairly substantial shift as well, is it not? Didn't see last nights, but was under the impression is was suppressed quite a bit like the GFS?

yea the UK jumped at least 200 miles NW

[Allsnow]

With a southern stream s/w digging that far south, there should have been more ridging than 0z and 6z showed due to stronger WAA. That should have slowed down the flow to allow a phase to happen over the CONUS, instead of offshore. This looks like a more "classical" solution.

So your saying the syrface does not the depict the low as west as it should be? In classical do you mean set-up for a east coast snowstorm?

[NittanyWx]

DT in the general thread saying the GFS is too far east based on H5. JSYK.

Edit:

Took a second look at that, and DT is on the money.

[gkrangers]

at 108n hrs look at the 500 mb map

then the surface

IMO the Low is still waaaaaaaaay too far east given that the 500 Low closed and negative SHOULD be capturing it and pulling it back

This crossed my mind too when I was watching the 500mb panels. I switched to the surface and was actually a bit surprised to see the GFS that far east. I would have expected a bit closer to the coast. Hopefully the GFS starts to pull it in a bit more tonight.

[chubbs]

DT in the general thread saying the GFS is too far east based on H5. JSYK.

Could be. At hour 108 looked like it was going to completely close off mid+upper levels over Va. In any case it is very close.

[A-L-E-X]

from DT:

at 108n hrs look at the 500 mb map

then the surface

IMO the Low is still waaaaaaaaay too far east given that the 500 Low closed and negative SHOULD be capturing it and pulling it back

[am19psu]

So your saying the syrface does not the depict the low as west as it should be? In classical do you mean set-up for a east coast snowstorm?

This run of the GFS look ok regarding its connection btw H5 and the sfc. Maybe a touch farther west at T+120, but not much.

By classical, I mean in the Norwegian Cyclone Model sense.

[eduggs]

Why bother asking that? Meteorologists aren't scientists.

Did you take your statistical mean of every ensemble solution yet?

Not this crap again. Taking thermodynamics, fluid mechanics, diff equations etc... doesn't make someone a "scientist." That said, many mets have advanced degrees and can be considered as such. But it's a meaningless term as anyone with a particular analytical mindset can think rationally and apply scientifically knowledge effectively.

I wanted to know how a guy could eyeball model errors. That has little to do with science.

[A-L-E-X]

Could be. At hour 108 looked like it was going to completely close off mid+upper levels over Va. In any case it is very close.

Just a minor correction is needed to make this a major hit. At any rate, this is probably where we want to be 100 hrs + out lol-- especially with the known SE bias of the GFS. Just working with the GFS and EURO at this point, leaving all other modeling out of the equation. Let's see where the GGEM goes, but aren't its verification scores less than the other models?

[eduggs]

With a southern stream s/w digging that far south, there should have been more ridging than 0z and 6z showed due to stronger WAA. That should have slowed down the flow to allow a phase to happen over the CONUS, instead of offshore. This looks like a more "classical" solution.

I don't understand the "should have been" part. "It would have been nicer if"... or the model physics is wrong?

[Guest Patrick]

Perhaps a stupid question, but I think valid:

Why is there a high pressure center depicted just to the west of the storm we are tracking on the H126 panel? Is this telling us something is wrong, or is this throwing our storm for a loop. Looks like HR120-126 is when the storm really gets shunted east, so I think it's a valid question.

My very amateurish guess is that it is some representation of a pretty big dry slot, and the pressure so low, that the final solution is clouded. Of course, it IS hr 126 on the GFS, just wondering. Any better answers? Thanks!

This run of the GFS look ok regarding its connection btw H5 and the sfc. Maybe a touch farther west at T+120, but not much.

By classical, I mean in the Norwegian Cyclone Model sense.

[psv88]

psv, probably should engage in that "think before you post" mentality.

Why? i think its a very fair, relevant question.

People cite Wes, JB, DT, PB and J, as much as the GFS and Euro as if they are their own models...am i wrong?

Does anyone else get annoyed with all the references to these guys? Or at least JB..come on

[NittanyWx]

I wanted to know how a guy could eyeball model errors. That has little to do with science.

By having an extensive knowledge of atmospheric interactions and the behaviors of pressure systems at different levels of the atmosphere.

Does that answer your question?

[Manny]

This an encouraging run, similar set up and phase like the Euro, but not enough to pull it closer, but a Stark contrast to previous runs, way different.

[Weathergun]

12GFS is entirely "northern stream" driven. The initial potent s/w currently near the west coast appears to completely dampen in the gulf of mexico. This might be the same evolution as the Euro, but it's more difficult to tell with 24hr panels instead of 6hr.

Yes. It uses the northern stream to crush the southern stream system. That leads to the typical SE bias it has. I don't buy it. The NAM doesn't even show that.

[A-L-E-X]

psv, probably should engage in that "think before you post" mentality.

He should also learn how to place his responses outside of others' quotes-- basic reasoning skills, really.

[psv88]

By having an extensive knowledge of atmospheric interactions and the behaviors of pressure systems at different levels of the atmosphere.

Does that answer your question?

eduggs...i think we all get what you mean...but you are taking it to the extreme. Humans have the ability to look at a model and see where the computer may have overcalculated, had a poor input etc....no need to rehash again...

[am19psu]

I don't understand the "should have been" part. "It would have been nicer if"... or the model physics is wrong?

No, of course the model physics aren't wrong. They solve the Navier-Stokes equations using a set of initial conditions.

However, there are certain parametrizations used to explicitly solve the equations. For example, for clouds, models only produce a certain opacity over a grid point, versus explicitly resolving clouds. Same with updrafts and downdrafts. This can lead unrealistic solutions, particularly when dealing with mesoscale type events that are less than 25 km in extent (or 15 km in the Euro).

Now, will you please drop your condescending line of questioning each time a meteorologist questions a particular model solution? There are things that we look for that clue us in on what the probable final solution will look like, based mainly on experience in the field.

[A-L-E-X]

Why? i think its a very fair, relevant question.

People cite Wes, JB, DT, PB and J, as much as the GFS and Euro as if they are their own models...am i wrong?

Does anyone else get annoyed with all the references to these guys? Or at least JB..come on

There is such a thing as a meteorological interpretation of where a model will go in the future-- this is where "science meets art"-- unless youre blind, you see that the GFS just made a HUGE jump, and a much smaller one is necessary to make it a major hit.

[eduggs]

Why? i think its a very fair, relevant question.

People cite Wes, JB, DT, PB and J, as much as the GFS and Euro as if they are their own models...am i wrong?

Does anyone else get annoyed with all the references to these guys? Or at least JB..come on

PB&J

I believe Wes is great at describing the implications of various charts and explaining underlying physical principles. He's also rightly conservative with mid-range forecasting. Otherwise none are particularly great prognosticators compared to mid-range guidance, despite what everyone says.

[NaoPos]

Why? i think its a very fair, relevant question.

People cite Wes, JB, DT, PB and J, as much as the GFS and Euro as if they are their own models...am i wrong?

Does anyone else get annoyed with all the references to these guys? Or at least JB..come on

Jb hypes... the mets on here dont..

They breakdown model runs, give out explanations why this or that is happening. Maybe your just jealous.

I mean, this is a weather disco board, i couldn't see why the life of me why anyone would want to quote a PRO MET ...... thats like saying the news quotes barack obama for no reason..

[psv88]

He should also learn how to place his responses outside of others' quotes-- basic reasoning skills, really.

My apologies sir. I am currently writing an Appellate brief for a client and i was typing very fast.

[A-L-E-X]

No, of course the model physics aren't wrong. They solve the Navier-Stokes equations using a set of initial conditions.

However, there are certain parametrization used to explicitly solve the equations. For example, for clouds, models only produce a certain opacity over a grid point, versus explicitly resolving clouds. Same with updrafts and downdrafts. This can lead unrealistic solutions, particularly when dealing with mesoscale type events that are less than 25 km in extent (or 15 km in the Euro).

Now, will you please drop your condescending line of questioning each time a meteorologist questions a particular model solution? There are things that we look for that clue us in on what the probable final solution will look like, based mainly on experience in the field.

It's laughable because some of these people dont even know how to read a map and they would question a professional's interpretation.

Folks, it's about a lot more than reading models..... the human brain has a capacity for insight that no computer, not even one with AI, can replicate.

[Zelocita Weather]

It's laughable because some of these people dont even know how to read a map and they would question a professional's interpretation.

Folks, it's about a lot more than reading models..... the human brain has a capacity for insight that no computer, not even one with AI, can replicate.

When does the new GGEM come out?

[eduggs]

eduggs...i think we all get what you mean...but you are taking it to the extreme. Humans have the ability to look at a model and see where the computer may have overcalculated, had a poor input etc....no need to rehash again...

Not by eyeballing a static chart. Only after the fact with reassessment or computers to perform bias correction. The "extreme" is correct in this case.