Jump to content
  • Member Statistics

    17,611
    Total Members
    7,904
    Most Online
    NH8550
    Newest Member
    NH8550
    Joined

January 2023 Medium/Long Range Pattern Discussion Thread


Carvers Gap
 Share

Recommended Posts

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.

Screen_Shot_2023-01-15_at_2.13.41_PM.png

 

  • Like 4
Link to comment
Share on other sites

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.

  • Like 1
Link to comment
Share on other sites

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.  

Link to comment
Share on other sites

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.

  • Like 2
Link to comment
Share on other sites

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.

  • Like 1
Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

  • Like 2
Link to comment
Share on other sites

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.

  • Like 1
Link to comment
Share on other sites

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.

Screen_Shot_2023-01-15_at_3.36.16_PM.png
Screen_Shot_2023-01-15_at_3.36.06_PM.png
Screen_Shot_2023-01-15_at_3.35.55_PM.png
Screen_Shot_2023-01-15_at_3.32.03_PM.png

 

  • Like 2
Link to comment
Share on other sites

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

  • Like 1
Link to comment
Share on other sites

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.  

  • Like 1
Link to comment
Share on other sites

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

  • Like 1
Link to comment
Share on other sites

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.

  • Like 1
Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.  

  • Like 2
Link to comment
Share on other sites

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.  

Link to comment
Share on other sites

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……

  • Like 1
Link to comment
Share on other sites

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.  

Screen_Shot_2023-01-15_at_4.08.16_PM.png

 

 

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

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...