January 2023 Medium/Long Range Pattern Discussion Thread

[Carvers Gap]

At 180, the 12z Euro has now changed rain over to snow on Plateau.  Nice setup.

[Carvers Gap]

That has the makings of a big storm on the 12z Euro.  Does it trend to the GFS and cut?  I could.  But for now, very nice run.

[Holston_River_Rambler]

It's going to fun to see who blinks first, GFS or Euro! 

[Carvers Gap]

We want the 12z Euro to be correct.  What follows that storm is also full of multiple winter chances.

[Carvers Gap]

This may be a "pay me now or pay me later setup."  If it cuts, it sets the boundary for the next storm on the 27th.  If it doesn't cut, it forms a storm w/ the 22nd/23rd piece of energy.  

[Carvers Gap]

FWIW, w/ so much cold in play over the Plains, the CMC and Euro arrive pretty much at the same place by the end of their runs(cold front headed east).  Neither have budged much.  It is odd to see the Euro w/ a progressive bias, but is has had a slight one at times this winter.  Again, I suspect the deterministic GFS is having feedback issues over the West.  The Canadian and Euro (paired together) for the long wave pattern has been a good pairing all winter.  Right now, the GEPS scores the coup if the Euro deterministic is correct.  

The 12z GEFS does not agree w/ the 12z GFS deterministic.  It is really the GFS deterministic vs its own ensemble as well once the storm on the 22nd passes.  Those is a pretty big difference.  This feels like a similar analysis to the December outbreak.  Ride w/ the ensembles as the operationals are going to be all over the place.

 

[Carvers Gap]

This is the 12z EPS for the Jan 22/23 system.  That is about where we want it.  Some cutters, but majority take the low road.

 

[tnweathernut]

8 minutes ago, Carvers Gap said:

This is the 12z EPS for the Jan 22/23 system.  That is about where we want it.  Some cutters, but majority take the low road.

 

 

Looks pretty simple………Stronger low, warmer and west.  Weaker low doesn’t necessarily mean less precipitation and would almost certainly mean a chance at a thermal profile more conducive to a winter event somewhere across a larger section of the mid-south.

[jaxjagman]

teleconnections on the GEFS seems to want a +ao/-pna,not what you would like to see in the long range right now

[Carvers Gap]

57 minutes ago, tnweathernut said:

Looks pretty simple………Stronger low, warmer and west.  Weaker low doesn’t necessarily mean less precipitation and would almost certainly mean a chance at a thermal profile more conducive to a winter event somewhere across a larger section of the mid-south.

I think the strength/depth/intensity of the cold air behind it will also matter...especially for the ensuing storms which follow.  The CFSv2 is now showing 20-25F degree BN departures for the first week of Feb.  Cold dumps into the Plains and spreads eastward (EDIT).  Interesting to see where this goes for sure.  

[tnweathernut]

3 minutes ago, Carvers Gap said:

I think the strength/depth/intensity of the cold air behind it will also matter...especially for the ensuing storms which follow.  The CFSv2 is now showing 20-25F degree BN departures for the first week of Feb.  Cold dumps into the Plains and spreads westward.  Interesting to see where this goes for sure.  

I don’t want 20-25 BN departures…..  let it go westward.  I’m still getting pipe claims from the last arctic outbreak.

[Carvers Gap]

The 12z GEPS/EPS ensembles have trended to cold filtering into the Plains.  Both are considerably colder than 0z.  Even the GEFS has cooled considerably during the past couple of days for the timeframe from 23rd to the 30th.  What comes after the 30th is open for fun debate.  The EPS has the 500 BN heights in the northwest to end the run, but surface anomalies have quite cold temps over the US from the Rockies eastward.  The GEPS is crazy cold.  The EPS seems like a good compromise between the aggressive GEPS and feedbacky GEFS runs at 12z.

[Carvers Gap]

1 minute ago, tnweathernut said:

I don’t want 20-25 BN departures…..  let it go westward.  I’m still getting pipe claims from the last arctic outbreak.

Yeah, I think this is strat warm stuff.  Modeling is crazy haywire in the LR....Outside of the GEFS(which I don't discount BTW), modeling is quite cold for our area and seems to be strengthening with each run.

[*Flash*]

15 minutes ago, jaxjagman said:

teleconnections on the GEFS seems to want a +ao/-pna,not what you would like to see in the long range right now

West/central TN can work with a +AO but that combo...yeahhh, not so much. If you had a strong enough +PNA or -EPO, we've seen that overcome a +AO/+NAO for our region. Windows will eventually come...but I wonder if they'll be the separate week-long variety as opposed to a 2+ week type.

[jaxjagman]

Even East Asia has been changing the last couple days.GFS want to build a Aluetian Rex block, the Euro seems to following it but not a Rex,East Asia looks cold for a couple days but then it warms back up.Aluetian high would mean a SER,POOP PATTERN

[snowmaker]

12 minutes ago, Carvers Gap said:

I think the strength/depth/intensity of the cold air behind it will also matter...especially for the ensuing storms which follow.  The CFSv2 is now showing 20-25F degree BN departures for the first week of Feb.  Cold dumps into the Plains and spreads westward.  Interesting to see where this goes for sure.  

Did you mean cold spills in the plains and goes eastward? Just curious and want to make sure I read you right. Thanks for all your thoughts on the long range and weather in general.

[Carvers Gap]

Here is what we are dealing with.  These are 5day ensemble means for d10-15.  The CMC is the most extreme.  The EPS seems like a good compromise as the GEFS seems to not see the cold in the East.  At this range, I recommend a blend of all three, and that gives us a really good pattern.   The last image is for kicks and giggles.  That is the Feb2-7th temp anomaly map from the CFSv2.  Again, surface pressure anomalies are not the same as 500mb anomalies.  With cold air residing near the surface, it is very important to look at surface anomalies which will be AN as the result of cold HP.  Cold air can cut under the SER which is why overrunning is a concern.

 

[jaxjagman]

5 minutes ago, *Flash* said:

West/central TN can work with a +AO but that combo...yeahhh, not so much. If you had a strong enough +PNA or -EPO, we've seen that overcome a +AO/+NAO for our region. Windows will eventually come...but I wonder if they'll be the separate week-long variety as opposed to a 2+ week type.

I agree we seem to be finally getting the Pac Jet out but now we deal with the S/jet,arggg

[Carvers Gap]

I hope if anything the models slides above provide examples of what kind of cold air is about to enter the pattern.  Models have been adamant for weeks that NA would cool down.  There is an increasing likelihood that now verifies.  Get those source regions colder w/ shortening wavelengths, and let's see what happens.  

[jaxjagman]

9 minutes ago, *Flash* said:

West/central TN can work with a +AO but that combo...yeahhh, not so much. If you had a strong enough +PNA or -EPO, we've seen that overcome a +AO/+NAO for our region. Windows will eventually come...but I wonder if they'll be the separate week-long variety as opposed to a 2+ week type.

I do agree a better PNA would squash that S/Jet.we'd probably see a BETTER hp to the NW possibly even somewhere into the Cen Plains,jmho

[Carvers Gap]

11 minutes ago, *Flash* said:

West/central TN can work with a +AO but that combo...yeahhh, not so much. If you had a strong enough +PNA or -EPO, we've seen that overcome a +AO/+NAO for our region. Windows will eventually come...but I wonder if they'll be the separate week-long variety as opposed to a 2+ week type.

The 12z GEFS EPO mean is negative.

[Carvers Gap]

[Carvers Gap]

I don't think we see a +PNA anytime soon, but it would be welcomed if it was.  I think we see the -EPO force Canadian cold into the Rockies and then strong cold fronts usher it eastward.  The EPO could very well be the mechanism which forces the cold into the Lower 48.  The SER will fight.   At some point, I do wonder if it all comes eastward per the CMC and CFSv2.   The other development is the NAO region showing some hints at rejuvenation.    Certainly there are multiple options on the table, and even the GEFS has cold coming eastward at times....it has the stormiest look of all modeling.

[Carvers Gap]

And meanwhile, if the 12z Euro is correct(or still just trending northwest which is likely), there is a trackable system this weekend or shortly thereafter if the 12z GEFS is correct.  

[tnweathernut]

With this much cold showing it won’t bother me to see a cutter.  Even something that cuts west of the apps can be beneficial for our snow loving members in west (and maybe middle) TN.  Wouldn’t be a bad thing to see something cut, drag the boundary deep into the SE and then the next wave have more cold to work with.  All in all I’m encouraged for the last week of January.  

[Carvers Gap]

3 minutes ago, tnweathernut said:

With this much cold showing it won’t bother me to see a cutter.  Even something that cuts west of the apps can be beneficial for our snow loving members in west (and maybe middle) TN.  Wouldn’t be a bad thing to see something cut, drag the boundary deep into the SE and then the next wave have more cold to work with.  All in all I’m encouraged for the last week of January.  

Yeah, we have been dealing with cruddy source regions for two weeks(still managed and upslope event even though).  One consistent variable among modeling is quite severe cold.  If that cold chills Canada, modeling nailed that aspect from about 4 weeks.  A deepening storm over the East could potentially send a lot of that eastward until the SER fights back.  It could just park in the west and not move(GFS operation), but the MJO would argue that it comes eastward(maybe all of it per CMC).  For me, I have been kind of conditioned during the past couple of winters to think the cold dumps west and won't move eastward or stalls on the Plateau.  So, that could happen.  But some of the historical winter patterns have the Rockies to the Apps cold.  It has been a long time since that occurred, but having most of the Lower 48 cold is not without precedent.  That said, the SER is definitely Nina climatology, so I think it shows.  We just don't want a standing ridge as Jax aptly notes.  

[Carvers Gap]

Again, this is the stuff I don't share as often as I should.  This is one extreme.  Obviously, warmth is the other.  

 

 

[tnweathernut]

10 minutes ago, Carvers Gap said:

Yeah, we have been dealing with cruddy source regions for two weeks(still managed and upslope event even though).  One consistent variable among modeling is quite severe cold.  If that cold chills Canada, modeling nailed that aspect from about 4 weeks.  A deepening storm over the East could potentially send a lot of that eastward until the SER fights back.  It could just park in the west and not move(GFS operation), but the MJO would argue that it comes eastward(maybe all of it per CMC).  For me, I have been kind of conditioned during the past couple of winters to think the cold dumps west and won't move eastward or stalls on the Plateau.  So, that could happen.  But some of the historical winter patterns have the Rockies to the Apps cold.  It has been a long time since that occurred, but having most of the Lower 48 cold is not without precedent.  That said, the SER is definitely Nina climatology, so I think it shows.  We just don't want a standing ridge as Jax aptly notes.  

We always have to walk a tightrope in the mid south……. We actually need some SE ridge.  Will be fascinating to watch the next couple of weeks play out.  Not worried about February yet, just looking for the next possible track.  As you mentioned, we found an upslope event to track in the middle of a terrible pattern so it can happen……

[jaxjagman]

13 minutes ago, Carvers Gap said:

Again, this is the stuff I don't share as often as I should.  This is one extreme.  Obviously, warmth is the other.  

 

 

Thats not a horrid look if it happens,but it seems this pattern we are in is so progressive and we cant get nothing to lock in

[Carvers Gap]

2 minutes ago, jaxjagman said:

Thats not a horrid look if it happens,but it seems this pattern we are in is so progressive and we cant get nothing to lock in

Very true.  I think of that SE ridge is going to be key and if we can get a mechanism for that cold to surge eastward.  I think we really want that cold in the Plains and not over the Rockies.