Winter 2024/2025 January Thread

[Carvers Gap]

Before the 0z suite last night, this was trending towards nothing for us re: 1.10.   At 12z we have seen the energy kept south of us - that was task #1.  Now, we have some room if it wants to come back northwest.  It may continue to trend SE or it comes back NW.   But if modeling had continued as it did yesterday, it was not going to be a frozen result for most.  The GFS was a solid 6-8” storm.  The Euro was prob 2-5”.  Blend those and that is a good result.   
 

Time will sort this out.  

[tnweathernut]

For everyone that doesn’t know (I didn’t), we have a dedicated thread for late week.  :-)

[matt9697]

I think we are headed in the right direction. I think I need to move to the snowbelt region of upstate NY, this modeling stuff is too stressful! 

[Daniel Boone]

1 hour ago, Carvers Gap said:

The 12z Euro is going the route of the 6z GFS.  It has another storm around 276.  I wonder if modeling is feeling that NAO now...sure seems like it.  Combo of western ridging and Atlantic blocking should yield those runs from time to time.

Could be factoring MJO in some too.

[Carvers Gap]

13 minutes ago, Daniel Boone said:

Could be factoring MJO in some too.

Definitely a pattern change coming as the ensembles have all diverged from one another around d13.  The 12z suite has multiple options.  The GEPS unleashes the worst cold of the winter.  The EPS is still cold.  Both the aforementioned ensembles have a full latitude trough which I think would be likely between the 20th and 28th as a transition.  The GEFS puts the trough in the West...probably the right solution but maybe 5-8 days early.  Its bias is to be too quick in breaking down Atlantic blocks.  The really interesting thing to me is that if the NAO holds....it could provide a pathway forward to more winter if the Pac breaks down.  The NAO is much better at producing winter later in the season......

As for the MJO....just tough to know.  It is dragging its feet.  That means it "could" be slower to transition to a Western trough, and might allow another pulse of cold after the 20th.  I do wonder if we can get to the 30th in one piece (meaning still winter to be found)...if the shorter wavelengths of February provide destructive interference to the MJO as it rotates to the warm side.  If the NAO holds, we could still manage more winter.

One last thought....I do wonder if the worst cold shot of winter is not quite on modeling yet?  If this pattern is going to break towards spring after this, that usually occurs after a rather extreme cold shot and/or storm.  Something to watch for.  The Euro is definitely toying with that.  The Canadian is pretty much there.  Warning shots were fired by modeling at 12z for a cold shot just after d15.

[Daniel Boone]

37 minutes ago, Carvers Gap said:

Definitely a pattern change coming as the ensembles have all diverged from one another around d13.  The 12z suite has multiple options.  The GEPS unleashes the worst cold of the winter.  The EPS is still cold.  Both the aforementioned ensembles have a full latitude trough which I think would be likely between the 20th and 28th as a transition.  The GEFS puts the trough in the West...probably the right solution but maybe 5-8 days early.  Its bias is to be too quick in breaking down Atlantic blocks.  The really interesting thing to me is that if the NAO holds....it could provide a pathway forward to more winter if the Pac breaks down.  The NAO is much better at producing winter later in the season......

As for the MJO....just tough to know.  It is dragging its feet.  That means it "could" be slower to transition to a Western trough, and might allow another pulse of cold after the 20th.  I do wonder if we can get to the 30th in one piece (meaning still winter to be found)...if the shorter wavelengths of February provide destructive interference to the MJO as it rotates to the warm side.  If the NAO holds, we could still manage more winter.

One last thought....I do wonder if the worst cold shot of winter is not quite on modeling yet?  If this pattern is going to break towards spring after this, that usually occurs after a rather extreme cold shot and/or storm.  Something to watch for.  The Euro is definitely toying with that.  The Canadian is pretty much there.  Warning shots were fired by modeling at 12z for a cold shot just after d15.

Agree with everything you said man . Gefs more than likely too quick transitioning to western Trough. I saw where the usual heat mizers on the main forum are hugging up with it after it starting showing the flip, lol. 

[Carvers Gap]

6 minutes ago, Daniel Boone said:

Agree with everything you said man . Gefs more than likely too quick transitioning to western Trough. I saw where the usual heat mizers on the main forum are hugging up with it after it starting showing the flip, lol. 

It is always possible it can be correct.  The GFS especially can be a canary in the cold mine.  But...the 12z GFS went full glacial yet again(two runs in a row), and ended w/ a monster cold high crashing southeastward.  The GFS is usually the one I watch for changes.  I still like the pattern lasting until the 20th.  I might even extend that 3-5 days now w/ the MJO dragging along.  Then, maybe a transition of 5-7 days after as the trough retrogrades into the Mountain West.  I do think we will probably see a ridge in the East pop, but I suspect cold continues to push from Montana at least to the Apps.  I am a little less certain of that, but it is a hunch.  If you look at good winters, those winters seem to find a way to bridge between cold shots.  If all of the cold at some point comes south, I think winter is done after that.  However, if it releases in pulses like we are seeing in modeling...it could find a second wind.  The analogs that I used for winter have a very cold March.

For whatever reason, I am just not watching the MJO right now.  I should, but am not.  I read Holston's posts and that is pretty much my update.  

What is incredibly encouraging, the MJO hasn't even started its rotation into the cold phases yet.  Maybe that last sentence is the best news of the day, including rumors of storms.....

[Carvers Gap]

15 minutes ago, Daniel Boone said:

Agree with everything you said man . Gefs more than likely too quick transitioning to western Trough. I saw where the usual heat mizers on the main forum are hugging up with it after it starting showing the flip, lol. 

And if you hand't shown me a single weather model as a kid, I would have noted that winter was progressing as normal IMBY.  Also noting, I grew up in Knoxville as a kid (I am a Knoxville native).  Lots of little snows so far.  Cold start to winter, 7-8 day interlude of warmth, and back to cold.  Really, that is about as good as it gets (so far!) IMBY.

[Matthew70]

38 minutes ago, Carvers Gap said:

It is always possible it can be correct.  The GFS especially can be a canary in the cold mine.  But...the 12z GFS went full glacial yet again(two runs in a row), and ended w/ a monster cold high crashing southeastward.  The GFS is usually the one I watch for changes.  I still like the pattern lasting until the 20th.  I might even extend that 3-5 days now w/ the MJO dragging along.  Then, maybe a transition of 5-7 days after as the trough retrogrades into the Mountain West.  I do think we will probably see a ridge in the East pop, but I suspect cold continues to push from Montana at least to the Apps.  I am a little less certain of that, but it is a hunch.  If you look at good winters, those winters seem to find a way to bridge between cold shots.  If all of the cold at some point comes south, I think winter is done after that.  However, if it releases in pulses like we are seeing in modeling...it could find a second wind.  The analogs that I used for winter have a very cold March.

For whatever reason, I am just not watching the MJO right now.  I should, but am not.  I read Holston's posts and that is pretty much my update.  

What is incredibly encouraging, the MJO hasn't even started its rotation into the cold phases yet.  Maybe that last sentence is the best news of the day, including rumors of storms.....

The MJO to me is huge in that it still has the cold phases to rotate thru.  Especially in the heart of winter.  

[Carvers Gap]

4 minutes ago, Matthew70 said:

The MJO to me is huge in that it still has the cold phases to rotate thru.  Especially in the heart of winter.  

As long as it will go there, yes!  This "should" be a prolonged series of cold shots.  We are just in day 3 of what should be almost a 3 week cold spell.  

[AMZ8990]

I’ve got a good thunder and lighting show going on at the moment as this line of storms pushes through west Tn and north Ms.  It’s eerily similar to the way things played out before our January snow last year.  

[John1122]

4 minutes ago, AMZ8990 said:

I’ve got a good thunder and lighting show going on at the moment as this line of storms pushes through west Tn and north Ms.  It’s eerily similar to the way things played out before our January snow last year.  

You should get some back side flakes if the NAM is correct. It shows some right over your area.

[jaxjagman]

11 hours ago, Holston_River_Rambler said:

Looks like the convection in the MC is finally starting to quiet down, with a pretty large convective system in Polynesia:

 

It's been so bad we've almost retrograded to 6 on the RMMs:

CFS has been showing this for several days.A Rossby Wave will get into the IO and slow the  progression into the IO and potentially show a stronger signal into the IO

[Daniel Boone]

3 hours ago, Matthew70 said:

The MJO to me is huge in that it still has the cold phases to rotate thru.  Especially in the heart of winter.  

That's what I'm thinking the Eps and couple others may be starting to key on in keeping the cold longer or reintensifying what they'd backed off from.

[Holston_River_Rambler]

We've finally started our trek out of the COD:

Maybe we can get it to stall in one or two like it has recently in 6 and 7? Does this guarantee anything, no, of course not, but at least it isn't the same old same old. 

[Carvers Gap]

Long range deterministic runs and their ensembles are honking for an overrunning event around the 20th.   That probably would impact western areas.  I have seen that setup many times, and it is there plain as day on modeling.

[nrgjeff]

After that said system, models try to break the cold. Warm front would make sense after a last over-runing event.

Or, you know, there's a strato warming event forecast at the same time. Release or Reload?

[Carvers Gap]

1 minute ago, nrgjeff said:

After that said system, models try to break the cold. Warm front would make sense after a last over-runing event.

Or, you know, there's a strato warming event forecast at the same time. Release or Reload?

Can I choose both?

[Carvers Gap]

Interestingly, there are some fairly major changes post Jan 20 on both the EPS and GEPS.   They are not putting the trough in the West.  Instead, it is a broad trough over the eastern 2/3 of the country.  Fairly big break in continuity.

[BNAwx]

9 minutes ago, Carvers Gap said:

Interestingly, there are some fairly major changes post Jan 20 on both the EPS and GEPS.   They are not putting the trough in the West.  Instead, it is a broad trough over the eastern 2/3 of the country.  Fairly big break in continuity.

This may be one of those rare winters where it just finds a way to lean cold in our neck of the woods.  I’m sure the pattern breaks at some point, but finding a way to keep a trough in the east during the coldest time of the year would be awesome.

[Carvers Gap]

Yesterday, deterministic runs found a cold shot late in the run.  The 12z EPS and GEPS are frigid late in their runs.  The 18z GEFS is now leaning in that direction. 

[Carvers Gap]

Look at that source region....18z GEFS.

[Carvers Gap]

Still a pretty decent signal for overrunning between the 20th-25th.  Honking pretty good.  Cold stops at the Apps with it being seeded from Montana.  We have seen that setup many times during the past decade.  For western areas of the forum, that has been money.  If the cold is strong enough, it can reach all of the way to the Apps - periods of ice, zr, rain, snow over a 2-3 day timeframe.  Something to keep an eye on.....

[John1122]

The GFS was back to a nice hit in the timeframe Carvers noted above. 3-6 inches from Nashville east basically, 1-2 along the southern end of the eastern valley, and out west.

[Carvers Gap]

12z GFS Kuchera is a glacier.  I am not where I can post it, or I would for posterity.

[Carvers Gap]

Both the 12z Euro and GfS just bury the forum.

[Carvers Gap]

Been a long, long time since I have seen three ensembles like we have seen at 12z.