January 2023 Medium/Long Range Pattern Discussion Thread

[Carvers Gap]

This will work.  And this matches ensembles.  Way out there, but many were using this model to cliff dive in other forums.   This will change I am sure, but this is an example of where this could go.

[Carvers Gap]

6 minutes ago, fountainguy97 said:

The 180-210 timeframe has a small potential. Looks very cutter-esque though.

I think modeling senses a cold shot is coming, and can't decide which system to accentuate.  This is nearly the same setup we saw back in December.  It took modeling some time to sort through which system was going to bring the cold.  

[jaxjagman]

12 minutes ago, Carvers Gap said:

I think modeling senses a cold shot is coming, and can't decide which system to accentuate.  This is nearly the same setup we saw back in December.  It took modeling some time to sort through which system was going to bring the cold.  

GFS keeps hinting a REX block around the Aluetians long range,dont think we want to see that

[Daniel Boone]

1 hour ago, jaxjagman said:

GFS keeps hinting a REX block around the Aluetians long range,dont think we want to see that

Yeah, lr will tend to want to show some enso base state pattern influences such as Alaskan/Aleutian ridging. Probability is higher of those occurrences with Nina base state as we know.  Hopefully, a PV stretch or MJO will thwart that but, won't be surprised if the former happens. Wavelengths will begin shortening in Feb. as Carver alluded to so , things will shuffle for sure.

[Carvers Gap]

I continue to really like the timeframe of Jan23-Jan27th for a couple of chances for middle and/or west TN.

[snowmaker]

Just now, Carvers Gap said:

I continue to really like the timeframe of Jan23-Jan27th for a couple of chances for middle and west TN.

I hope we do get some chances soon. It rarely goes wall to wall warm or cold inTennessee. Do you still think the first few weeks of February may bring some chances as well? I have lived in Tennessee my entire life so I know how fast things can change.

[tnweathernut]

I can’t remember the year, but it’s been fairly recent (last 10 to 12 years I think) when modeling was beginning to head in a great direction for winter lovers and then a SSW popped into view that ended up coming to fruition.  Hype was off the charts and the SSW happened.  Can kicking happened in near term and that short range pattern never materialized.  Then the SSW affected the longer range too in sending the severe cold to the other side of the globe, leaving NA well above average I’m the heart of winter.

[PowellVolz]

I can’t remember the year, but it’s been fairly recent (last 10 to 12 years I think) when modeling was beginning to head in a great direction for winter lovers and then a SSW popped into view that ended up coming to fruition.  Hype was off the charts and the SSW happened.  Can kicking happened in near term and that short range pattern never materialized.  Then the SSW affected the longer range too in sending the severe cold to the other side of the globe, leaving NA well above average I’m the heart of winter.

Not sure it’s the same year but I remember at the first(ish) of January about 6-8 years ago mods were showing a major pattern change with arctic air. About 10 days out the mods started pushing it back a day. The cold front eventually went through in the middle of February. One of the most bizarre winters I can remember.


.

[Holston_River_Rambler]

1 hour ago, tnweathernut said:

I can’t remember the year, but it’s been fairly recent (last 10 to 12 years I think) when modeling was beginning to head in a great direction for winter lovers and then a SSW popped into view that ended up coming to fruition.  Hype was off the charts and the SSW happened.  Can kicking happened in near term and that short range pattern never materialized.  Then the SSW affected the longer range too in sending the severe cold to the other side of the globe, leaving NA well above average I’m the heart of winter.

I think that was as recently as 18-19. We'd had one in late Feb 18 and it had produced a nice -NAO period that helped out the east coast (MA and NE), so we were hopeful that it would have the same result. It happened right as the MJO was in the 4/5/6 phase and just enhanced to bejeebus out of it there lol since it displaced some cooler air to the tropic latitudes in the tropopause. 

We did get an wave running a front for the "Dayton leeside micro low" event towards the end of January. 

here is a post from @EastKnox that kind of summed it up, lol:

 

Current EPS depiction for this Jan 24, lol : 

[Carvers Gap]

5 minutes ago, Holston_River_Rambler said:

I think that was as recently as 18-19. We'd had one in late Feb 18 and it had produced a nice -NAO period that helped out the east coast (MA and NE), so we were hopeful that it would have the same result. It happened right as the MJO was in the 4/5/6 phase and just enhanced to bejeebus out of it there lol since it displaced some cooler air to the tropic latitudes in the tropopause. 

We did get an wave running a front for the "Dayton leeside micro low" event towards the end of January. 

here is a post from @EastKnox that kind of summed it up, lol:

 

Current EPS depiction for this Jan 24, lol : 

18-19 was it.  December 18 was crazy cold.  It looked like that might continue and poof!

[Holston_River_Rambler]

We were still waiting on the pattern change from the strat as of page 16 of the Jan thread. we did eventually get a storm, but it was just a light wave riding a front kind of a thing. 

I think this was all it amounted to:

Apparently I was so eager to get a satellite shot I couldn't wait until full daylight. 

[Carvers Gap]

2 hours ago, snowmaker said:

I hope we do get some chances soon. It rarely goes wall to wall warm or cold inTennessee. Do you still think the first few weeks of February may bring some chances as well? I have lived in Tennessee my entire life so I know how fast things can change.

Yeah, it is currently mid January.  I would be very surprised if we don't see more chances.  I mean, how many people say this current upslope chance two weeks ago?  

I think the windows are:

Jan 22-23

Jan27 roughly.

As for February, I would again be shocked if February and March didn't deliver some chances.   To me, there is plenty of variability in modeling to make me think we see more winter.  My mind hasn't changed on that all.  That said, I (nor anyone else) don't know the future.  So the "winter cancel" or "winter continues" crowd is nothing more than following a Groundhog in Pennsylvania - might be right and might not.  But with half of January and all of February to go, climatology says we should have some more chances.

[Carvers Gap]

I would argue the pattern change is at hand.  It will very likely be at hand by the 22nd.  The MJO is rolling through 8 as we get this cold shot.  The HB block is highly likely about to be gone.  Now, does the new pattern favor us?  That is the question of the hour.  I think the changing wavelengths of Feb give us a shot.  Also, it is very important to note that our cold source region is  very likely about to vastly improve which means storms aren't dealing with marginal air - that is the biggest aspect to the pattern which is likely to change.

[snowmaker]

10 minutes ago, Carvers Gap said:

I would argue the pattern change is at hand.  It will very likely be at hand by the 22nd.  The MJO is rolling through 8 as we get this cold shot.  The HB block is highly likely about to be gone.  Now, does the new pattern favor us?  That is the question of the hour.  I think the changing wavelengths of Feb give us a shot.  Also, it is very important to note that our cold source region is  very likely about to vastly improve which means storms aren't dealing with marginal air - that is the biggest aspect to the pattern which is likely to change.

Good info, I don’t know much about the MJO but some have said some of it’s plots have it skipping cold phases and heading to 4-5-6 which are warm phases. Others show it looping back in cod after traveling through I think 1 and or 2 if I am right? Right now I believe you said it was in low amp 8. What are your thoughts on this? I am trying to understand how mjo correlates and how much it impacts things. Thanks in advance.

[jaxjagman]

Starting to wonder if we are fixing to see the kiss of death for this winter as we head into Feb.CFS wants to show a standing wave into the WP,along with a strenghtening MJO signal,of course this could be wrong but you still dont want to see this

[Carvers Gap]

The 18z GFS has a great look on the 22nd.

[Carvers Gap]

35 minutes ago, snowmaker said:

Good info, I don’t know much about the MJO but some have said some of it’s plots have it skipping cold phases and heading to 4-5-6 which are warm phases. Others show it looping back in cod after traveling through I think 1 and or 2 if I am right? Right now I believe you said it was in low amp 8. What are your thoughts on this? I am trying to understand how mjo correlates and how much it impacts things. Thanks in advance.

Well, it is in the cold phases now so it hasn’t skipped them.  Some plots show 4-6 in a few weeks, and some show it crossing the COD after 3 and going to 6(which would likely bring it back to 8).  Some stall in the MJO in 3.   A warm tour is definitely a possibility.  I am just glad we are on this side of the Apps.  

[Carvers Gap]

I think we will know more after we get to the 23-27th timeframe.  Looks like we have two looks during that timeframe.  It is also important to remember that when looking at LR modeling, we just see the long wave pattern,  we don’t see the details.

[Holston_River_Rambler]

Quite an OP model war overnight with the Euro and GFS respectively sticking to their guns. GFS hangs up the shortwaves out west, Euro allows for a more progressive boundary and shortwaves. 

Looks like the Euro control also popped a -NAO at 300+ hr. 

[Carvers Gap]

The 0z Euro has a nice pass on the 22nd and then a clipper right behind it.

[matt9697]

Seems like with a lot of the modelling, one commonality is the rainfall; just really need the cold to win this battle sooner rather than later, without any of that moisture in the form of ice! 

[Carvers Gap]

There is actually a lot of improvement w/ ensembles overnight.  The 6z GEFS is actually quite cold - that is a flip by that model.  There is quite a lot of agreement now. HB block should be gone by the 22nd-23rd.  Cold should push eastward in 2-3 shots.

[Carvers Gap]

Yeah, just double checking temp anomalies....that is substantial improvement overnight.  Most ensemble modeling now shows a 7 day(minimum) window beginning around the 23rd.  The cold shot on Friday was the opening round which worked to initiate the breakdown of the HB Block.  Surprisingly, ensembles are in decent agreement this morning.  Details about the system on the 22nd-23rd are going to be murky at this range.  For now it looks like it cuts through mid-state...but the Euro does not and take the low road

[matt9697]

2 minutes ago, Carvers Gap said:

Yeah, just double checking temp anomalies....that is substantial improvement overnight.  Most ensemble modeling now shows a 7 day(minimum) window beginning around the 23rd.  The cold shot on Friday was the opening round which worked to initiate the breakdown of the HB Block.  Surprisingly, ensembles are in decent agreement this morning.  Details about the system on the 22nd-23rd are going to be murky at this range.  For now it looks like it cuts through mid-state...but the Euro does not and take the low road

Never a dull moment with the weather 

[Silas Lang]

Hopefully the cold pattern materializes and actually happens. I swear, outside of 5 days, the models show a different solution everytime. Maybe that's a sign they are struggling with an upcoming pattern change? 

[Carvers Gap]

I would say at this point that I am growing confident that Canada will be refilled w/ cold air within the next ten days.  That resets our cold source.  Now, the real discussion is whether it dumps west and holds or heads eastward per the CMC.  The severity of the cold is on par with the December outbreak.  I would suspect that models are going haywire, because extremely cold air is very hard to model.  It would make sense to head into the West as that is the path of least resistance due to snowpack....then I think it spreads eastward between the 25-27th.  It is a good rule of thumb that when models are bouncing around, very cold air is likely entering the pattern.  In my mind, severely cold air plunging into the Lower 48 is increasing in likelihood.  Does it hold in the Rockies or head into the Plains and fight the SER.  I have said it once and I will say it again...this is a very good setup for west TN.   The timing and severity of the cold is strikingly similar to the ice storm set-up from a few years back.

[Carvers Gap]

Also, right now at this range, it is wise to use ensembles w/ models bouncing around all over the place.  

[Carvers Gap]

I often don't show my entire hand when looking at medium and LR weather.  Maybe I should, but sometimes it causes consternation when folks see it as the gospel.  So spitballing, this is what I am looking at w/ the 12z ensemble.  That is d11, and that looks quite a bit different than the GFS deterministic.  Take a minute and look at the boundary (blue line/red line) over the forum area. That is the setup from the previous post which I am referring.  It is highly likely that modeling is getting that boundary incorrect.  The axis of that cold air mass is going to be massively important.  I suspect the GFS deterministic is too far to the West.  Why?  Its ensemble hints that the cold may press eastward more.  

 

[Carvers Gap]

The other thing which is showing up in the LR is the NAO returning.  There is a pretty significant reshuffle occurring (and about to occur) over the western hemisphere.  So right now modeling is juggling these things:

1.  Elimination of the Hudson Bay block

2.  Warming in the stratosphere over the polar regions of the Northern Hemisphere

3.  A possible return of HL blocking and the NAO

4.  Likely return of very cold air to North America and the Lower 48.  

One of those would cause havoc in LR modeling.  Add in four of those, and that leaves people and models sorting through layers of data.  This is what makes following the weather fun believe it or not.  It may end up in our favor and it may not.  But I like my chances at some point with all of that in play.  So, in general, I roll with Feb Nina climatology which says the cold drops into the Northern Rockies and pushes eastward against a SER which is gonna fight.

[Carvers Gap]

Indeed, the 12z Euro is coming in w/ a snow event for west TN for the 22nd and 23rd w/ an Apps runner about 173.