18z 12/24 model disco

[chademer07]

I think when I go on at 11 in Salibury, I will post 2 snowfall maps with the different scenarios. One further east and one further west. That is the best way I think I should do it at this point in time unless the GFS goes east at 0Z.

Anyone else have other ideas?! They are welcome!

Honestly, I think thats the best way to do it. With so much uncertainty right now, a high or low prediction could bust big time. Just say 0"-24"

[yoda]

Also FWIW... 23z RUC out to 18 hrs

[Ian]

The TX S/W is doing quite well and is nicely wrapped and perhaps a touch W of guidance, fwiw as well.

not sure it's west of guidance.. pretty close one way or another. gfs/euro sorta agree at this pt anyway with regard to that vort location and have it about where it is.

[Kevin Druff]

I think when I go on at 11 in Salibury, I will post 2 snowfall maps with the different scenarios. One further east and one further west. That is the best way I think I should do it at this point in time unless the GFS goes east at 0Z.

Anyone else have other ideas?! They are welcome!

The people that will b**ch won't care what you say. The people that your advertisers care about will appreciate your candor that your guidance is at odds with each other and you really don't know what's going to happen.

I would offer your "best guess" of which of the two is right, but give folks the information and let them decide what to do.

[jimmosk]

I think when I go on at 11 in Salibury, I will post 2 snowfall maps with the different scenarios. One further east and one further west. That is the best way I think I should do it at this point in time unless the GFS goes east at 0Z.

Anyone else have other ideas?! They are welcome!

To expand on this idea, I'd have your two maps be sort of "best case scenario" and "worst-case scenario" (keeping in mind that different people will have different ideas about which of those is which!), and emphasize that while it's natural to say the truth will probably be a blend of both, that's really not the case here -- depending on the trajectory the system takes it really might be all, or nothing.

[CT Rain]

I think when I go on at 11 in Salibury, I will post 2 snowfall maps with the different scenarios. One further east and one further west. That is the best way I think I should do it at this point in time unless the GFS goes east at 0Z.

Anyone else have other ideas?! They are welcome!

I definitely would not do that. 1 map with the "most likely" scenario and leave yourself room to change. If you're not comfortable with that no map at all.

2 maps just makes it look like you have no idea and can't make a call.

[DoctorMu]

I saw this in the PHL/NYC thread... thought it might help some in here.

It's really getting wound. Rain, wind, and temp gradient were more than expected on the ground...s/w has some punch

[yoda]

It's really getting wound. Rain, wind, and temp gradient were more than expected on the ground...s/w has some punch

Are you in Texas?

[AlYourWxPal]

I definitely would not do that. 1 map with the "most likely" scenario and leave yourself room to change. If you're not comfortable with that no map at all.

2 maps just makes it look like you have no idea and can't make a call.

Yea, I was thinking that as well. I might just not show a map tonight, but we don't have a 6 PM tomorrow night so I would only be able to show the map at 10 and 11. I think I might just go very conservative right now and say 1-3....but just emphasize this can change.

[Amped]

0z looks a lot like the 18z GFS at 6hrs

[Clinch Leatherwood]

0z looks a lot like the 18z GFS at 6hrs

Problems dont look severe but maybe they really do propogate.

Anyway at 0z it looks like the GFS did struggle with the structure in TX. It maintains a single strong feature throughout and that's probably going to effect speed. Second it didn't catch that max coming into NW ND. This was one of NCEP's stated errors.

The NAM was a little too deep or fast in Missouri/just west. Did okay elsewhere.

That's the problem, parts of the puzzle are right on each, wrong as well. Normally these really wouldn't make the difference between these mega hits and a miss, it would be more like who gets 6" vs 12". Odd.

[Riptide]

Problems dont look severe but maybe they really do propogate.

Anyway at 0z it looks like the GFS did struggle with the structure in TX. It maintains a single strong feature throughout and that's probably going to effect speed. Second it didn't catch that max coming into NW ND. This was one of NCEP's stated errors.

The NAM was a little too deep or fast in Missouri/just west. Did okay elsewhere.

That's the problem, parts of the puzzle are right on each, wrong as well. Normally these really wouldn't make the difference between these mega hits and a miss, it would be more like who gets 6" vs 12". Odd.

There is also a second max further to the SE. Nothing really stands out and the 0z GFS will most likely hold steady.

[eduggs]

I think when I go on at 11 in Salibury, I will post 2 snowfall maps with the different scenarios. One further east and one further west. That is the best way I think I should do it at this point in time unless the GFS goes east at 0Z.

Anyone else have other ideas?! They are welcome!

Go conservative. Euro/UKMET match reasonably well. GGEM, 06z GEFS in same ballpark Always the usual caveat that things can still change depending on exact track yada yada.

[Clinch Leatherwood]

There is also a second max further to the SE. Nothing really stands out and the 0z GFS will most likely hold steady.

True counting the TX system as 1, there are really about six in play.

18z 18h GFS vs 12h 0z RUC...really very small differences. Astounding, you'd really expect to see some glaring errors at this point right?

[Amped]

Go conservative. Euro/UKMET match reasonably well. GGEM, 06z GEFS in same ballpark Always the usual caveat that things can still change depending on exact track yada yada.

Well if WSW and WSW are needed for NYC- BOS they need to go out ASAP after the 0z run.

[weatherweather]

21z sref west. and still snowing

[DoctorMu]

Are you in Texas?

College Station. 1-2 in of rain, lightning, cold core w/ temps dropping nearly 30°, 20-25 mph winds Not quite closed with the SW-NE axis, but sassy..

[armyftball]

Pessimism & Optimism have flipped so much with this storm it's incredible. Definitive statements on prior model success & failure appear to have been premature. This is certainly more interesting than an obvious OTS or an obvious bomb. No matter what eventually happens when it hits the east coast, this storm is already bringing a renewed sense of humbleness to all.

[Kmlwx]

21z sref west. and still snowing

That's pretty darn impressive. I've heard folks say that can hint at where the NAM will go. I guess we will see.

[snowman21]

Well if WSW and WSW are needed for NYC- BOS they need to go out ASAP after the 0z run.

Why so soon? The snow won't even start up this way until some time Sunday night, and if we some how reach warning criteria it wouldn't be until Monday anyway. A watch or warning now would be a 5th or 6th period watch with a ton of uncertainty and details to be resolved. Unless 00z Euro comes west, NWS is going to stay with the status quo. OKX has 50% chance light snow late Sunday/Sunday night and partly sunny Monday in the metro area. Even in their most NE'rn zones in coastal CT at the RI border they are only going with little or no accumulation on Sunday night with flurries followed by clearing Monday. I could see BOX pulling the trigger after 00z Euro or after the 12z runs for eastern Mass.

[WeatherFox]

And with surface low crossing over the benchmark on the 21Z Short Range Ensembles. Very exciting for us NYC folks (fingers crossed) for the trend to be our friend.

21z sref west. and still snowing

[winterymix]

I think when I go on at 11 in Salibury, I will post 2 snowfall maps with the different scenarios. One further east and one further west. That is the best way I think I should do it at this point in time unless the GFS goes east at 0Z.

Anyone else have other ideas?! They are welcome!

Just let the audience know that the most thoughtful meteorologists

see the "more east solution" as more likely but that could need to

be adjusted. Advise your viewers to check in for updates especially in the morning.

Take the path of least regret; knowing there will be errors, make

your potential forecast error as small as possible.

[vinylfreak89]

Ask and you shall receive. Here is the 500mb analysis as of 6:40pm, 20min before 00z. Hope this helps! FWIW, I think the 18z GFS is handling the two features nicely.

those are excelent maps... how are they generated and are they available to the public?

[DJ Amenzo]

Listen, I completely respect you mets. I understand that you have an enormous amount of stress factor with your jobs in that you deal directly with the general public. Major forecast errors can lead to a threatening job status. But for the love of God how can we all sit here and honestly ignore the blatantly obvious signals and trends the GFS/NAM/SREF and even to some degree the European and Canadian schemes have been sending us over the past 24 hours?!?!? The ECMWF and GGEM have respectively shown an epic snowstorm formation in their UL depictions of this upcoming event; both with minor trending further S and W each and every run @ 500mb and also with the dynamical jet streaks shown blowing around the base of the trough in TWO epic formations, not just one. The first will send it on its belly, the latter acts to only amplify the trough further and capture our NNEwardly propogating bombogenesis. As for the NAM, its utterly historic in its UL trough formation as well as level of phasing of all associated waves. Forget the sfc depictions, they're always the last to catch up, especially on the NAM in my experiences. The GFS, even from 18z YESTERDAY has been sending us remarkable signals of epic doom along the east coast, in both its depth of the E CONUS trough complex, associated wave handling, its axis and orientation and the afforementioned epic jet dynamics. The models screwed this one up badly from the MR. It happens regularly. It happened all last year other than the Feb 10th event. However, the models do NOT suddenly jump this far westward and amplified inside of this range unless something incredibly dynamic and mammoth is coming in the form of amplification. And certainly can be said for the GFS in this range. That said, the 21z SREF just rolled in with major to historic implications, as well as unheard of run-to-run changes on the 00z NAM thats rolling in. Its safe to say the NAM has jumped to the GFS camp even at the sfc. All one needs to do is take a look at WV/sat data to see that the GFS and its camp is winning. I don't need to explain why.

I'm not intending to insult anyone, so I apologize if I have. Goodluck to us all and Merry Christmas!!

[winterymix]

NAM out to 36 hrs.

Not completely sold on the GFS.

Deep moisture at 700 mb remains offshore.

[winterymix]

moisture inflow at 42 hrs. is out to sea.

entrance of 300 mb is suppressed south;

this supports the out to sea solution

[DJ Amenzo]

moisture inflow at 42 hrs. is out to sea.

for the moment. The trough is going on its belly in response to jet streak, and ala Jan 2000, a wall of UVM is about to crush the N Mid-Atlantic coastline. Lets not also forget how HUGE of a shift this is

[rossi]

its not a miss at all your getting hit good at hr 54