December 2022 Medium-Long Range Disco

[Terpeast]

1 minute ago, Ralph Wiggum said:

Maybe this will morph into a colder and farther S version of yesterday's system. I mean, that wouldn't be a terrible thing....atmospheric memory and all those other  superstitious myths.

Unless the GFS digs in and scores the coup of the century, this may be the best case scenario... cutter with redevelopment over CAD with a small thump to dry slot. I'll take it if it the models compromise to that scenario.

[jayyy]

I know the gfs is on an island right now, but it’s the new King, and to see the GFS OP and GEFS in line on a key feature 54ish hours out is enough for me to still feel there’s a decent chance it’s right.

The euro’s wheelhouse is more in the mid range which is where it showed a similar evolution to what the GFS is currently showing in regards to how it handled the energy out west. If the euro is indeed doing its usual song and dance of hanging back too much energy out west in the 54-84 hour range, then it’s plausible that the result downstream at D7 (the final evolution of the storm) is incorrect.

Of course, the GFS could end up being wrong and could eventually cave to the other “camp” in the coming 2-3 days, but if we’re strictly going off performance in the 48-84h range, I’d take the GFS over the Euro given it’s success over the past year since it was upgraded. The GFS’s consistency at 5h & 500mb from run to run has been pretty remarkable, and having support from its ensemble only bolsters it’s credibility IMO

Anything’s possible, so we take this a day at a time. If the 00z gfs and tomorrows 12z gfs continue its current look, I have a feeling other models play catch-up in due time.


.

[yoda]

Um, it has? From this afternoons LWX AFD:

 

 

 

Broad, highly anomalous ridging will build into the Arctic, sending

 

a deep upper low south into the northern Plains, Great Lakes and

 

Ohio River Valley by Thursday. The collision of this cold upper low

 

with warmer temperatures near the Gulf Stream will likely generate a

 

strong area of low pressure in the vicinity of the East Coast.

 

Details in track, strength, and timing remain uncertain, and overall

 

confidence remains low; however, it should be noted that most long

 

range guidance has been unusually consistent in hinting at a

 

potential wintry precipitation scenario late next week.

 

 

 

&&

 

 

 

 

 

 

 

 

[Weather Will]

NBM 18Z v 12Z…..we are off to a good start….

[Terpeast]

Just now, Weather Will said:

NBM 18Z v 12Z…..we are off to a good start….

Curious. If NBM is a "blend" of models, and most models are going cutter, how can this be?

[Twilly05]

1 hour ago, snowmagnet said:

So the GFS  is offering up snow on snow on snow the 23rd, 26th, 29th.., thé CMC has rain, and the Euro has dry and cold?? Am I following this right?

Yup. Pretty much it

[BristowWx]

Maybe because the GFS was so snowy it’s skewing the mean? 

[Weather Will]

1 minute ago, Terpeast said:

Curious. If NBM is a "blend" of models, and most models are going cutter, how can this be?

I am hoping it means that the 18z runs will start converging toward the GFS…

[lpaschall]

1 minute ago, Terpeast said:

Curious. If NBM is a "blend" of models, and most models are going cutter, how can this be?

Well, its 31 models and we focus on the big players.

[yoda]

2 minutes ago, Terpeast said:

Curious. If NBM is a "blend" of models, and most models are going cutter, how can this be?

Guess they are heavily favoring GFS/GEFS?

[IronTy]

Trying to decide if we stay in Calvert for Christmas or go camping in Garrett county.  Figure I'm covered no matter what happens but would be more comfortable at home in Calvert with the wood stove blasting so I'm voting for GFS.  

[NorthArlington101]

4 minutes ago, Weather Will said:

I am hoping it means that the 18z runs will start converging toward the GFS…

the NBM seems to ingest a helluva a lot of data from models I've never even heard of -- but I'm pretty confident its not getting access to future runs/has predictive value for the next cycle. Think this is (unfortunately) just a byproduct of a HECS GFS run being added to the blend. It even has the exact same stripe of max snow totals 

[Weather Will]

18Z NBM at the end of its run with storm 2 included.  Epic Christmas weekend if it verifies.  Don’t give up hope yet, we have a ways to go….buckle up!!!!

[psuhoffman]

4 minutes ago, Terpeast said:

Curious. If NBM is a "blend" of models, and most models are going cutter, how can this be?

Gfs had 38” over me.  Let’s say that includes the ggem euro and ukmet. The average of 38,0,0,0 is  9.5 which is what it shows. 

[Terpeast]

Just now, psuhoffman said:

Gfs had 38” over me.  Let’s say that includes the ggem euro and ukmet. The average of 38,0,0,0 is  9.5 which is what it shows. 

Yeah, skewed mean is probably the best explanation. That's why we have to be careful "blending" models together.

[Chris78]

10 minutes ago, Weather Will said:

NBM 18Z v 12Z…..we are off to a good start….

What's the 18z based off of if none of the 18z models have ran yet?

[Its a Breeze]

11 minutes ago, yoda said:

Um, it has? From this afternoons LWX AFD:

 

 

 

Broad, highly anomalous ridging will build into the Arctic, sending

a deep upper low south into the northern Plains, Great Lakes and

Ohio River Valley by Thursday. The collision of this cold upper low

with warmer temperatures near the Gulf Stream will likely generate a

strong area of low pressure in the vicinity of the East Coast.

Details in track, strength, and timing remain uncertain, and overall

confidence remains low; however, it should be noted that most long

range guidance has been unusually consistent in hinting at a

potential wintry precipitation scenario late next week.

&&

 

Yeah, pretty much. Every single one has shown snow for the region at some point.

The EURO may not be what we want...but it still consistently has at least a little snow for everyone.

The CMC started this whole mess (first to show 12"+)

[CAPE]

NBM is useless given the disparity, and the blend probably includes models with low or no skill at this range. Only runs that matter are the next GFS and Euro.

[Disc]

6 minutes ago, Chris78 said:

What's the 18z based off of if none of the 18z models have ran yet?

Think of the NBM as a cycle or two behind the deterministic guidance. The 18z NBM has the 12z GFS/GEFS, but still has the 00z ECMWF/EPS and some 06z guidance. Full ECWMF 12z guidance is not within the NBM until its 21z run.

[Chris78]

Just now, Disc said:

Think of the NBM as a cycle or two behind the deterministic guidance. The 18z NBM has the 12z GFS/GEFS, but still has the 00z ECMWF/EPS and some 06z guidance. Full ECWMF 12z guidance is not within the NBM until its 21z run.

Thanks for the info. Sounds useless in this scenario 

[psuhoffman]

14 minutes ago, lpaschall said:

Well, its 31 models and we focus on the big players.

I could be totally wrong but I thought a lot of those were meso scale models that don’t go out that far. At that range is it still incorporating that many models?  

[psuhoffman]

6 minutes ago, Disc said:

Think of the NBM as a cycle or two behind the deterministic guidance. The 18z NBM has the 12z GFS/GEFS, but still has the 00z ECMWF/EPS and some 06z guidance. Full ECWMF 12z guidance is not within the NBM until its 21z run.

That makes sense thanks. So it’s telling us we should have been celebrating 12 hours ago and we already know it’s going to be depressing at 0z lol. Nice model.  

[Ralph Wiggum]

35 minutes ago, Steve25 said:

I personally couldn't ever care less about what the Icon, Ukie, or frankly even the CMC show. But when they're all in agreement with the Euro, that's a very bad sign and trend. One is going to move towards the others at 0z tonight...

Not being a Deb, but I think we are quickly losing the big MECS scenario in our regions. When was the last time numerous guidance moved almost in unison away from a MECS/HECS then subsequently moved back towards the single model holding out? It isn't common to see it play out like that. 

[psuhoffman]

18 minutes ago, Weather Will said:

18Z NBM at the end of its run with storm 2 included.  Epic Christmas weekend if it verifies.  Don’t give up hope yet, we have a ways to go….buckle up!!!!

But it does have the Mt psuhoffman maximum 

[psuhoffman]

3 minutes ago, Ralph Wiggum said:

Not being a Deb, but I think we are quickly losing the big MECS scenario in our regions. When was the last time numerous guidance moved almost in unison away from a MECS/HECS then subsequently moved back towards the single model holding out? It isn't common to see it play out like that. 

Jan 2000 guidance had that hecs from range then lost it. But they never actually brought it back until it was snowing lol. 

[Ralph Wiggum]

Did we extrapolate the 18z NAM yet or did I miss that post?

[Ruin]

35 minutes ago, Twilly05 said:

Yup. Pretty much it

why i hate models lol they all mostly say something different when they  were just in agreement. after they had that big update in 2018 it feels like models got worse in many ways 

[Terpeast]

7 minutes ago, psuhoffman said:

Jan 2000 guidance had that hecs from range then lost it. But they never actually brought it back until it was snowing lol. 

That was an out-to-sea scenario, and then it turned north at the last minute. 

I remember Doug Hill saying "okay, I'm a little suspicious, this seems to be moving north not east..."

We're not going to do the reverse unless there's a redevelopment scenario.

[CAPE]

The model disparity in the handling of the TPV underscores the importance of having negative height anomalies underneath the NAO ridge in order for it to act as an effective block, encouraging a favorable storm track underneath. Fill that area in with a ridge and it becomes largely impotent and of little use to achieve the desired outcome.

[olafminesaw]

8 minutes ago, Ralph Wiggum said:

Did we extrapolate the 18z NAM yet or did I miss that post?

Looks to be more in the GFS camp still (dare I say another step towards the GFS?).