Winter 2024/2025 January Thread

[Wurbus]

Another banger run for GFS incoming. CMC was also good and both models seem hellbent on bringing the polar vortex down after the 22nd. Not sold on that since they were also signaling that feature a few weeks ago, but if we can keep the pattern going, that is a win in my book.

[Wurbus]

I'll take whatever E18 is cooking up. Not often you see the yellow & oranges stretching down into TN.

[matt9697]

47 minutes ago, Wurbus said:

I'll take whatever E18 is cooking up. Not often you see the yellow & oranges stretching down into TN.

Signal is there for another system to track for sure. Current one will result in 3" or 4" for my area. 

[Matthew70]

20 hours ago, Knoxtron said:

23 hours ago, jaxjagman said:

threats.php

storm today was an absolute bust for my area.  Maybe 2.5”.  The model that was less precip was spot on.

[tnweathernut]

46 minutes ago, Matthew70 said:

storm today was an absolute bust for my area.  Maybe 2.5”.  The model that was less precip was spot on.

Probably a letdown because it was being built up for much more.  Getting 2.5" of snow in middle Tennessee, south of Nashville is pretty good.  Go find Cantore and blame that rascal.

[Carvers Gap]

Just the way it goes.  We have 0.5” and that will be it for MBY unless the atmosphere rings out moisture in the cold last night.  We had more here Weds.  At least county kids will be able to get back to school.  They haven’t gone back yet due to Last Sunday’s snow and Wednesday’s surprise snow north of 81.  
 

The next two weeks have promise.  Likely flip coming during that last week at some point, however.   February looks warm, and almost all seasonal modeling had that.  March could likely flip back cold,  

[Daniel Boone]

53 minutes ago, Matthew70 said:

storm today was an absolute bust for my area.  Maybe 2.5”.  The model that was less precip was spot on.

The Northern System over Illinois pulled moisture north into it. Areas in Indiana , Illinois and Ohio are getting more than forecasted. The precip area with the southern System stayed predominantly South. 

[jaxjagman]

2 hours ago, Wurbus said:

I'll take whatever E18 is cooking up. Not often you see the yellow & oranges stretching down into TN.

i was about to say that,give me weenie 18

[tnweathernut]

Where is @Hurricane?  Looks to be ripping down his way.  Hopefully he is able to enjoy it before any dry air works in.

[Carvers Gap]

The next big window (excluding a couple of clippers this week for northern areas) is the 18-22nd.   Winter options on the table are a cutter, overrunning, ana front or coastal.  An ana front looks plausible.  Overruning also plausible.  I think we see at least one cutter.  Rain chasing snow looks likely in cutter scenarios.  Still a good 13-15 days left before a significant warmup.  The cold analog package for January (wild card month) are likely going to win.  

[jaxjagman]

Still believe the Euro is out to lunch

[matt9697]

8 minutes ago, Daniel Boone said:

The Northern System over Illinois pulled moisture north into it. Areas in Indiana , Illinois and Ohio are getting more than forecasted. The precip area with the southern System stayed predominantly South. 

I though that it looked more strung out, and that makes sense, we got no where near 5"-8"

[midwoodian]

I though that it looked more strung out, and that makes sense, we got no where near 5"-8"

We got 5” in Signal Mtn.


.

[dwagner88]

2 hours ago, midwoodian said:

We got 5” in Signal Mtn.


.

Shockingly enough I think basically the whole Chattanooga metro got 5". Even the airport. I guess what they say about blind squirrels is true. 

[vortexse93]

6 hours ago, jaxjagman said:

Still believe the Euro is out to lunch

Winter wx is not my strong suit, especially at long range intervals but would like to know a little more on why the Euro is out to lunch when using the MJO?

 

[John1122]

The GFS says let's run it back. Still snowing in NE Tn/SW VA here. 

 

[John1122]

This is hard to beat in mid to late Jan. Jan 15th-Feb 15th is the heart of winter here. The most extreme cold and most snow we get, historically, arrives in that window. 

Some of that AN precip will be rain. But that angle of cold pointed at us from Eastern Montana to Minnesota basically what we see with big winter events and bitter cold here. That will keep us in the game for what I posted above. 

 

 

 

[matt9697]

Now, moving onto the upcoming pattern, what are the chances that we do this again?

[Holston_River_Rambler]

34 minutes ago, matt9697 said:

Now, moving onto the upcoming pattern, what are the chances that we do this again?

I'd say better than average after the 21st, as it stands now. Models have been consistently showing an arctic boundary pressing SE and waves running along it. The only question is timing everything out. Some runs have big hits, some nothing. 

Big upsides and nothings:

 

[Holston_River_Rambler]

6z Euro AI is a great example, but pretty much any major global model is showing some variation:

 

Boundary sets up and each wave drags it a bit further south. 

[matt9697]

4 minutes ago, Holston_River_Rambler said:

I'd say better than average after the 21st, as it stands now. Models have been consistently showing an arctic boundary pressing SE and waves running along it. The only question is timing everything out. Some runs have big hits, some nothing. 

Big upsides and nothings:

 

Having lived through multiple consecutive winters where we had no snow or anything to track, and now being the recipient of three consecutive winters - Januarys in fact - where we had snowfalls, I will take a better than average chance of doing it again this winter!

[matt9697]

1 minute ago, Holston_River_Rambler said:

6z Euro AI is a great example, but pretty much any major global model is showing some variation:

 

Boundary sets up and each wave drags it a bit further south. 

That is a crazy set up with someone scoring big time, difference between now and then is that it appears that we would have much colder air moving into the area in the wake of what ever systems come through, the temps at or near freezing this go around have really assisted my area in staying relatively passable. 

[Carvers Gap]

The overrunning look has been honking on models for the last 7-10 days at least.  The SER is about to fire once again, and that promotes overrunning (stalled cold fronts).  To me, an overruning event would probably affect only the western 1/3 of the state.  The last few events like that couldn't get over the western edges of the Plateau.  But let's see.  The cold appears to be stronger than the last few overrunning events of the past several years.  When it is strong, the overrunning can push to the spine of the Apps.  When cold dumps into Texas, that is a sure sign overrunning is possible for western areas.  Overrunning is not the only option as John noted overnight(reference his post about a redux).  I also think it is growing likely that we see an anafront IF the cold is as strong as modeled. 

And let's be clear about this so the gnashing of teeth is limited when the time comes.  Long range ext modeling is crystal clear that a pattern change is incoming when the MJO rotates into warm phases.  The good thing is that so far the warmer temps have been pushed back to around the end of the month after originally being depicted for the 20th.  Personally, I just want to see January's average temps in the tank.  I think February will be much above normal.   It wouldn't surprise me to see a record high or two broken.  Then, I think we do this one more time during March(late Feb if we are lucky).  If we can get the MJO to haul you-know-what across the warm phases, we could be in business quicker.  However, the end of January puts us at about 4.5 weeks with a colder pattern, and that is about the max duration that we can swing.  That doesn't mean it can snow when the MJO is in warm phases - it does and has before, but just tougher to get the job done. 

Short story....we have about 2.5 more weeks of good cold to deal with.  The AI hints we might be done with the cold around the 26th.  Global ensembles keep us in the freezer to the end of their 16 day runs.  I wouldn't be surprised to wake up one morning and see those flip shortly after the 25th...but I think we have until the last few days of the month.  The 18-22(maybe 23rd) looks like a good window to watch.

[matt9697]

4 minutes ago, Carvers Gap said:

The overrunning look has been honking on models for the last 7-10 days at least.  The SER is about to fire once again, and that promotes overrunning (stalled cold fronts).  To me, an overruning event would probably affect only the western 1/3 of the state.  The last few events like that couldn't get over the western edges of the Plateau.  But let's see.  The cold appears to be stronger than the last few overrunning events of the past several years.  When it is strong, the overrunning can push to the spine of the Apps.  When cold dumps into Texas, that is a sure sign overrunning is possible for western areas.  Overrunning is not the only option as John noted overnight(reference his post about a redux).  I also think it is growing likely that we see an anafront IF the cold is as strong as modeled. 

And let's be clear about this so the gnashing of teeth is limited when the time comes.  Long range ext modeling is crystal clear that a pattern change is incoming when the MJO rotates into warm phases.  The good thing is that so far the warmer temps have been pushed back to around the end of the month after originally being depicted for the 20th.  Personally, I just want to see January's average temps in the tank.  I think February will be much above normal.   It wouldn't surprise me to see a record high or two broken.  Then, I think we do this one more time during March(late Feb if we are lucky).  If we can get the MJO to haul you-know-what across the warm phases, we could be in business quicker.  However, the end of January puts us at about 4.5 weeks with a colder pattern, and that is about the max duration that we can swing.  That doesn't mean it can snow when the MJO is in warm phases - it does and has before, but just tougher to get the job done. 

Short story....we have about 2.5 more weeks of good cold to deal with.  The AI hints we might be done with the cold around the 26th.  Global ensembles keep us in the freezer to the end of their 16 day runs.  I wouldn't be surprised to wake up one morning and see those flip shortly after the 25th...but I think we have until the last few days of the month.  The 18-22(maybe 23rd) looks like a good window to watch.

I always like your posts, as they are so informative! We have some remaining chances, so that is good indeed! Hopefully, we can get through the rest of the season without having any major issues!

[Carvers Gap]

Just now, matt9697 said:

I always like your posts, as they are so informative! We have some remaining chances, so that is good indeed! Hopefully, we can get through the rest of the season without having any major issues!

Some model runs are loaded up with potential, and others are pretty barren.  Time will tell.  Hopefully we can reel in another event or two.

[matt9697]

2 minutes ago, Carvers Gap said:

Some model runs are loaded up with potential, and others are pretty barren.  Time will tell.  Hopefully we can reel in another event or two.

Looks like the long range is all the chatter in the MA forum!

[jaxjagman]

11 hours ago, vortexse93 said:

Winter wx is not my strong suit, especially at long range intervals but would like to know a little more on why the Euro is out to lunch when using the MJO?

 

Im not saying never use it,its still guidance.Sometimes it misses waves but corrects itself later,same with other models.It doesnt even have support from its members from some of its members,some are showing a stronger signal into the IO right now

[jaxjagman]

3 minutes ago, jaxjagman said:

Im not saying never use it,its still guidance.Sometimes it misses waves but corrects itself later,same with other models.It doesnt even have support from its members from some of its members,some are showing a stronger signal into the IO right now

 

[Carvers Gap]

This is the overruning event captured in about four frames.  Notice that each passing wave brings the ice and snow line eastward.  Sometimes, the first wave is the stronges(w Tenn folks know this from a few years back).  Sometimes, as seen with this setup(NOT the gospel), the last wave is the strongest and can resemble(or even be) a Miller A track.  These are just waves that slide along a slow moving frontal boundary.  This boundary is slow on many deterministic models and slow on ensembles.  If you put those maps in motion(just look at temp anomolies), you will see a hiccup or two as they slide across the TN Valley.  Those hiccups are the front stalling.  A stalled front is a hallmark of overruning events.  I think the chance of this occuring is growing with each models suite.  I don't know if the overruning will be the Ohio Valley, TN Valley, or even mid-South.  I would think our forum area is prime for this type of setup.

Just watch the blue lines press southeast......The third frame would be M TN snow.  The last would be E TN snow, and is the strongest of the four distinct impulses.  Note, this only occurs during a roughly 72 hour window.

Wave 1

Wave 2 (below)

Wave 3 (below)

Wave 4 (below)

 

[Carvers Gap]

The 6z GEFS had an almost identical setup but was faster.  It was centered from the 18th-20th.  Timing is key and differences exist at this range.  But seeing similarities is a good thing at range.  This look has been on modeling almost since d16 of that time frame was on modeling.  So, to see consistency from that far out is a good thing.  I like that it is on ensembles. I will add that often modeling is too far southeast with overruning - so beware.  It will often correct westward.  The last storm on this 6z GEFS run looked like this(preceded by other impulses):