Winter 2024/2025 December Thread

[Carvers Gap]

Crazy to see how differently the EP/GEP and GEFS are right now after d10.  They converged a bit yesterday, and have diverged again overnight.  Even the GFS operational is on an island.  The GFS really struggled with the cold during the past few weeks.  If it gets beat this time, I am going to have to retire it for a bit.  OTH, if it wins....big win for American modeling.  I won't say it isn't right - I learned a long time ago not to discount outliers in weather modeling.  However, it looks really off.   The 6z GFS is certainly plausible given climatology, and is one scenario we need to guard against....that the warm isn't just a 7 day warm-up.  FTR, I do think it is wrong, but I do consider it nonetheless.  Sometime in science evidence is presented which asks us to consider another solution.

[Holston_River_Rambler]

28 minutes ago, Carvers Gap said:

Crazy to see how differently the EP/GEP and GEFS are right now after d10.  They converged a bit yesterday, and have diverged again overnight.  Even the GFS operational is on an island.  The GFS really struggled with the cold during the past few weeks.  If it gets beat this time, I am going to have to retire it for a bit.  OTH, if it wins....big win for American modeling.  I won't say it isn't right - I learned a long time ago not to discount outliers in weather modeling.  However, it looks really off.   The 6z GFS is certainly plausible given climatology, and is one scenario we need to guard against....that the warm isn't just a 7 day warm-up.  FTR, I do think it is wrong, but I do consider it nonetheless.  Sometime in science evidence is presented which asks us to consider another solution.

Yeah that trough hung up over the SW doth maketh me a bit nervesome. 

We're firmly in MJO 6 after having spent several weeks in 4/5 and I always feel like there is a lag in the pattern over North America. I think we've seen this so many times though we're a little "once bitten twice shy" any time that trough starts to set up in the southwest.

 

 

[Holston_River_Rambler]

Just now, Holston_River_Rambler said:

Yeah that trough hung up over the SW doth maketh me a bit nervesome. 

We're firmly in MJO 6 after having spent several weeks in 4/5 and I always feel like there is a lag in the pattern over North America. I think we've seen this so many times though we're a little "once bitten twice shy" any time that trough starts to set up in the southwest.

 

 

I also don't like to to see BAMWX chest thumping on X. Bad sign.

Totally unscientific to let that to worry me, but it is what it is. 

[nrgjeff]

It's a good sell signal. When they get too bullish, sell natural gas. Not trading advice! I don't trade gas.

At least seasonable cold if not colder is still on tap for the first work week of January. Right during the warm holidays will be when to buy gas. Again not advice. 

[Carvers Gap]

Yeah, the 6z GEFS cooled considerably in the east for early January.  Let's see if that continues to trend that way.  I do think January gets pretty cold.  However, I don't trust the GFS at this time of year - been burned too many times both cold and hot with that model.  However, the Euro Weeklies have also burned me.  Really, it is the last part of the first week that is supposed to see a return to season and cold.  

EURO AIFS/GFS vs EPS/Euro deterministic/CPC/GDPS/GEFS(wobbly support from GEFS)

Considering the warm bias of the two on the left, I still like what the Euro Weeklies and American Weeklies portray as the likely result.  If you follow Richard G West on Twitter, the GFS is like that.  The dude is punking people with many tweets, but he sometimes throws some actual breaking news into the mix before anyone else has it.  So the GFS is kind of like the Richard G West of the news world.  

Amazing that January was a question mark back in August, and it still is with twelve days to go.  I think a good run of winter between Jan 5-20...after that is a considerable question mark.

[jaxjagman]

8 hours ago, Holston_River_Rambler said:

I also don't like to to see BAMWX chest thumping on X. Bad sign.

Totally unscientific to let that to worry me, but it is what it is. 

THIS !! ,i dont get myself in BAMS recent post why you are comparing the EPO and how good the Canadian model did to the Euro AIFS and calling AIFS a EPIC failure,i mean the AIFS is an experimental project,kinda silly to me to even compare the two

[jaxjagman]

Mid and long ranges believe you'd rather see height falls into East China into the Koreas and not the opposite.Instead the EPS shows this more into the Sea of Japan into the Western Pac,without a definitive sign of a -NAO your trough axis will,could be seemingly to far east of us to get much of anything but hoping for a clipper or possibly even  cold chasing rain with a chance even for severe weather

[Daniel Boone]

42 minutes ago, jaxjagman said:

Mid and long ranges believe you'd rather see height falls into East China into the Koreas and not the opposite.Instead the EPS shows this more into the Sea of Japan into the Western Pac,without a definitive sign of a -NAO your trough axis will,could be seemingly to far east of us to get much of anything but hoping for a clipper or possibly even  cold chasing rain with a chance even for severe weather

Yeah, that is the fear with the Pattern. The Troughiness we've been getting has really been too far East so far. We really need at least some blocking, NAO or WAR imo to help back the Trough with what liiks to possibly be a default Winter Pattern. Could be, if Nina exerts it's affects more later on it will actually help position the Trough further West. 

[Carvers Gap]

GEFS ext.....initiate the -NAO protocol.  Very cold run for that model.  At some point, we should see model ensembles begin to trend in one direction or the other.  Good trends today.  Let's see if they hold.  For now(stress that), the colder analogs look more likely to win out for January.  

[Carvers Gap]

The GEFS went from worst to first in about four runs today as it again caves to the EPS/GDPS models.  If we keep it in the old tomorrow, very good sign.  That sucker has a monster AK ridge and a -NAO.  Fingers crossed.  As we have seen during the past few years, that look can go very wrong(WAR city), but as is....nice run.

[Daniel Boone]

1 hour ago, Carvers Gap said:

GEFS ext.....initiate the -NAO protocol.  Very cold run for that model.  At some point, we should see model ensembles begin to trend in one direction or the other.  Good trends today.  Let's see if they hold.  For now(stress that), the colder analogs look more likely to win out for January.  

CPC had some cold Analogues in the Package. A couple not great but, the rest were. 95-96 and 84-85 in there as couple Tops. Only bad one was 01-02. 

[Carvers Gap]

8 minutes ago, Daniel Boone said:

CPC had some cold Analogues in the Package. A couple not great but, the rest were. 95-96 and 84-85 in there as couple Tops. Only bad one was 01-02. 

If that high latitude setup manages to trap the PV, could get interesting.  I have not seen that yet, but it could with that setup.  

[Daniel Boone]

Just now, Carvers Gap said:

If that high latitude setup manages to trap the PV, could get interesting.  I have not seen that yet, but it could with that setup.  

Exactly Carvers ! 

[Holston_River_Rambler]

That was some '96 like weather at the end of the 12z GFS. 

[Daniel Boone]

24 minutes ago, Holston_River_Rambler said:

That was some '96 like weather at the end of the 12z GFS. 

Yeah, hopefully things come together and we wind up with a snowier than Average Winter for a change. Just lioking at Radar, had the Trough been 100-150 Statute Miles further west we'd still be getting a barage of lake enhanced Snow Showers.

 Upon second thought, lol, really, had the storm off the coast developed further West we'd be getting that. Of course one could argue the point that that's a product of too far esst Trough. 

[beavis1729]

44 minutes ago, Daniel Boone said:

Yeah, hopefully things come together and we wind up with a snowier than Average Winter for a change. Just looking at Radar, had the Trough been 100-150 Statute Miles further west we'd still be getting a barage of lake enhanced Snow Showers.

 Upon second thought, lol, really, had the storm off the coast developed further West we'd be getting that. Of course one could argue the point that that's a product of too far esst Trough. 

Yeah, the "too far east trough" has really hurt the winter so far in much of the country...essentially anywhere east of the Rockies outside of the lake effect snow belts. That's a big chunk of real estate. The chinooks in MT/CO have been crazy.  Denver is +7.6F above normal for Dec so far, even vs. the warmer 1991-2020 normals...and this will probably increase even more by month's end.

This creates two problems: (1) the "angle of the cold" is all wrong, so we're left with generally windy and dry conditions (2) the western ridge is so far east that, when the trough relaxes/kicks out periodically, the warmth floods in quickly. That's what will happen during the next week starting around Christmas. We finally had a modest snow in our neck of the woods, and were looking forward to snow on the ground for our annual New Year's trip to central WI...but warm air will wipe out all the snow cover during the next week, even up around 44N and most of WI. Similar to the past 2 winters, the winter sports industry (mainly snowmobiling) is getting whacked up there again. Most years, they have a solid 3 months of reliable snow cover, from 12/15 to 3/15. Very unfortunate.

We need to shake up the pattern, and hopefully the trough will be further west in early Jan. As of now, it looks somewhat promising...but still way out there in model land.

[Carvers Gap]

The 12z GFS is on board now.  Complete cave, and maybe even more extreme than other modeling.  

As for how things are set up right now, I really don't mind it.  I have had snow in the air for the past two days - more days than I can count so far.  It is important in this area to remember that winter really doesn't start here (historically) until late December and early January in the valleys. So, I couldn't be happier with how the season has begun.  

Looks like a 7-10 day warmup beginning on Christmas.  Then, it sure looks like the bottom comes out.   Deterministic models are now seeing the cold which is what we want to see in deterministic models.  Ensembles have it.  Good connections.  

That ridge really wants to stay out west.  Honestly, we all may want a break towards the end of January should all of that verify.  Pattern looks pretty loaded at 12z(GFS).

[Carvers Gap]

We may see temps below zero, especially at higher elevations.  BN temps are COLD during January.  That is an overrunning setup if I have ever seen one.  I am not saying that is here, but somewhere east of the MS.  The GFS brings portion of the eastern valley into low single digits with no snow on the ground.  That is what the Weeklies have been hinting at.

[Carvers Gap]

Pretty rare to see the EPS with 10-11 degree BN departures.  12z has it over the TN Valley forum.  I would say at this point, the ingredients for a major snowstorm are beginning to show up on modeling for Jan5-20.  That is right smack in the middle of our coldest climatology.  To get those types of departures during our coldest time of the year is impressive.

[Carvers Gap]

This gives you an idea of how cold the air mass is that we are looking at for part of January....or all of it.  When we start seeing snowstorms into the Florida Panhandle, that shows how strong the air mass "could" be.

 

[John1122]

The Euro brings the cold and snow the GFS was showing yesterday, big hit for the Carolina piedmont. Brings a general 1-3 inch snow into parts of our area with chilly temps.

[nrgjeff]

They both still see that system but of course it's Day 12. Either way, evidence is building for a cold pattern starting a few days after the New Year. 

[John1122]

GEFS is pretty prime, blocking up top and out west. Major trough in the East. Cold starts moving in around New Years evening and we stay below normal through the end of the run. Basically everything that's warm from Christmas until New Years is cold from the 2nd until the end of the run on the 7th. GEPS is the same.

[Carvers Gap]

To echo John …the 12z GEPS and GEFS are about as cold as ensembles can get in the d10-15.  Wow.  Crazy to look at on Tropical Tidbits.

[Daniel Boone]

1 hour ago, John1122 said:

The Euro brings the cold and snow the GFS was showing yesterday, big hit for the Carolina piedmont. Brings a general 1-3 inch snow into parts of our area with chilly temps.

Yeah, 12z GFS went to a Cutter. Not surprised as it'll probably throw out every possible Solution until Game time.

    I'm not getting my hopes too high and being completely confident until around the 28- 30th or so and 80% of all Ensemble Members are showing the near perfect Pattern, as have been burned too many times. Not being a Debbie downer just a Realist.

I do think we are in for a colder January than we've had in quite some time but, still may be back and forth. If blocking does materialize then those extended very cold / snowy solutions may very well verify. The +QBO is what has me skiddish irt that however.

   

[John1122]

The weeklies keep the trough around in the East well into mid to late January. 

The Euro AI is bullish on the cold and storm potential as well.

As DB noted, I'll believe them more when we get close to them verifying. Too many can kicks in my lifetime to be sold as yet.

[Carvers Gap]

Never can rule out a can kick in this area!  However, generally we begin to see signs by now if that was to occur.  I do agree that we need to get it inside of d10.  However, the cold is on deterministic models.  When I get skiddish is when the Weeklies solutions continue to get pushed back and never really show up on the d1-16 models.  The thing that gives me confidence(rightly or wrongly) the ridge really wants to go out West.  We will probably understand that more once the pattern verifies(if it verifies) after winter.  For the ski slopes, I am super happy for them.

[Daniel Boone]

18 minutes ago, Carvers Gap said:

Never can rule out a can kick in this area!  However, generally we begin to see signs by now if that was to occur.  I do agree that we need to get it inside of d10.  However, the cold is on deterministic models.  When I get skiddish is when the Weeklies solutions continue to get pushed back and never really show up on the d1-16 models.  The think that give me confidence(rightly or wrongly) the ridge really wants to go out West.  We will probably understand that more once the pattern verifies(if it verifies) after winter.  For the ski slopes, I am super happy for them.

That western ridging tendency is what I like too buddy. That's one of my reasons I believe January will be a cold one overall . There's still that worry something akin to late December 1989 occurs. +PNA November and December. The Ridge suddenly got shoved East at the very end of December and never returned West. 

I don't know if there was any real concrete proof of what caused a wholesale 500 mb shift that never went back really at all. Although, it did by April as I recall several elevated Snowfalls then.  Hopefully, everything pans out for us. 

[*Flash*]

Kinda nervous middle TN will be on the cold dry side of things next month. The real fun seems to be on and east of the plateau. 

[Holston_River_Rambler]

Euro AIFS ensemble? 

https://arxiv.org/abs/2412.15832