Carvers Gap

The 12z GFS avoids the westward trekking slp, and sends a consolidated and highly amplified trough in the East around the 17th. If the GFS is wrong w/ the system on the 15th, and if it is more amplified as I suspect it might be....the rest of the pattern would be more amplified. As is, the trailing trough being the 15th amplification will be every bit as imposing.

The GFS almost got to where the ICON was...just too quick w/ the southern stream to make the phase. Let's see where the other deterministic runs go w/ that. IF It forms a coastal in reality...that is honestly about where we want it on the GFS w/ the westward trend and it missing the phase. If that phases, it could be well west of that.

At 156, the GFS misses the phases. Not unexpected from a model which has a progressive bias. Let's see where ensembles go with that. That said there is still a lot of energy behind the initial front which is dragging its feet.

The 6z AIFS Euro does that crazy deal where the slp cuts off over Idaho and heads to San Fran.. I think that is part of the feedback that we have seen all winter in that part of the world. If that doesn't occur(which I doubt it does), programmers across modeling need to take a serious look at what is going on in the western US w/ storm prediction - it is rough. With many millions of people living downstream of that...it needs to get fixed. There is almost assuredly some shared programming as evidenced by that pinched of low tracking westward over the US.

So far w/ the 12z suite is rolling: 1. The ICON hass a coastal system and could trend much bigger if real... 2. The GFS and RGEM both have pretty decent snow shower activity Sunday.

Yeah, I want the light blue hues over MBY.

The 18z AIFS Euro barely lets the eastern ridge build after the first retrograding cycle. It almost immediately retrogrades again into the Eastern Pac. The cold TPV sitting in the middle of the continent really won't let the ridge build over the East, and it squashes the SER. I am not seeing a tendency to retrograde the TPV into the West, not on the deterministic and not on the ensemble. The SER is going to try to flex, but IF the setup for the TPV is correct, I bet that trough is underdone. I hate to use a 360 map, but this is where models were originally showing the trough dumping into the West. Do you see a trough in the West? This is a TPV dominant pattern if it verifies, and that vortex could possibly rule the roost if real. The other trend I am seeing is the tendency for HL blocking to lock it in place which would prevent a retreat across the pole once in place. Let's see if this verifies. I am making NO promises this is legit as modeling has been "you know what" most of the winter at this range. This look is very common on many models. When modeling starts to key on major patterns like this, it can score at range.

18z GEFS stuff...

Some big dogs on the ensemble member group.

The 18z GEFS is bumping up the snow mean just a bit. Its ensemble continues to cool quite a bit.

Pretty good look pattern coming up. I think some in the forum scores...even if just a light event. I mean there are kind of two camps: a big dog or just bunches of small, northern events.

I legit am kicking around trying to find my way to the Sierra Nevadas (sooner than later) for an atmospheric river event. Vegas flights are cheap, but the drive....Reno is the best, but the connectors can be a problem.

Good to have you back in here, man!!! Hopefully you are feeling better. It looks like we are gonna be needing u very soon w/ the pattern shaping up. The real story right now(in addition to the Jan 11-21 window), is the sharp cooking across ensembles d10+. It wasn't there this morning. But -10 to-15 departures at this range is interesting. I gotta think some type of blocking is showing up...maybe a slower moving retrograding high, less prominent SER, OR as I suspect, the air mass in central Canada is gonna be legit and run the show.

The 12z EPS and GEPS are cold. The GEPS is next level and probably has some usual cold bias in play. The usually warm EPS...is picking up a very cold signal after the 20th as is the GEPS. Remember, "normal" gets it done at this time of year. I think the sharp cooling by ensembles might be driven by the NAO. My short warmup after the 21s might be in trouble. All ensembles are signaling a gradient pattern incoming.

Give me that pipeline continuing w/ the incoming trough from the 11th-21st, and let's roll.

On another note, I sure hope JB referenced @GaWx w/ his phase 6 "isn't always warm" backtrack(from warmth) post. Did he? If he didn't, he needs to.....

A great trend is the "re-stocking" of cold for NA. During many recent La Ninas, NA would get emptied of cold, the trough would drop into the West, and winter was over outside of the Rockies. I really don't see that pattern at all right now. If anything, winter may just be getting started.

The 12z Euro is one small, wintry system after another for our forum area. It has some nice systems embedded. I would be surprised if some in the forum don't score 1-2x w/ this trough... The Euro is loaded up as well.

And I will certainly take what the 12z GEM is cooking up as well. Lots of snow showers and cold between Jan 15-20th. I "think" we end up seeing an organized system come out of this, but several days of over-running(not heavy) is possible.

Yes, it pops a low as well. The AIFS version would likely be extended upslope over a large area...some mix or rain possible depending on time of day. With the amplitude of that trough, the likelihood of something "spinning up" is higher than normal.

I don't know on that one. I generally prefer just the normal Euro deterministic at this time of year. The Euro sometimes takes a little longer to trend. I like watching the GEM, GEFS, and ICOn as sometimes their turning radius is a bit tighter to steal a car term. The AIFS Euro is running now. I carves out a pretty amplified trough...I just can't see what precedes that trough quite yet as the hours haven't filled back in on this run.

The 12z GFS, and it cannot be trusted w/ that run, has four winter events and/or storms within its full run.

Been a while for E TN folks. I am not sure that happens here. To me, a strong neutral tilt trough is more likely around the 15th. That could change, but the vortices appear "real" at this point. The trough should be quite amplified. It may well try to spin something up. The amount of cold available is not a sure thing if it gets strung out. If it maxes out, then we might be in business. The wave after that doesn't look bad, and maybe the one after that even.

The GFS has been bad outside of day 5....really bad. Just look at the 500 vort map today. Crazy town. However, it is usable inside of d5. The agreement between the GFS, GEM, and ICON is a good thing. How that potential phase unfolds is important. Just look at the 500 vort maps and you can see the interaction. The good thing is that there may well be another window w/ the storm which follows the Jan15-16 storm.

Yes. I am still sifting through the entire suite. I don't see exceptional cold at this point, but seasonal looks likely during that time. The second window(second ridge retrogression) for cold looks like it could be winter's worst. This is why I am not overly sweating the MJO right now. The "storm window" where we see a deep eastern trough w/ lots of energy and cold diving into it between Jan 15-20th...want to guess the MJO phase? Six. The CPC MJO models loop the MJO into 8 by the end of the month. There is probably some lag(maybe a week) in that surface reflection here. But it makes sense that the MJO matches the next retrograding ridge cycle. If we can score in 6, roll a ridge east-to-west after that, and score phase 8 at the end of January or early Feb...that might be a really good rotation. See GaWx's comments about phase 6. Anyway, still plenty of uncertainty...but it the potential for an interesting few weeks of weather is increasing.