December 2022 Medium/Long Range Pattern Discussion Thread

[Carvers Gap]

11 minutes ago, Holston_River_Rambler said:

CMC looked to be heading somewhere nice at the end of its run. 

I think a Euro/CMC blend is probably in order.  The GFS is all over the place.  I give it some credit as it was first to find that the pattern was not going to be favorable prior after the 15th, but man...I don't know if I have ever seen it this erratic.  The Pacific is just not cooperating as well.  The other explanation is that very cold air is about to enter the pattern in the d10-15.  That could explain some things.  

[Met1985]

1 hour ago, Carvers Gap said:

I think a Euro/CMC blend is probably in order.  The GFS is all over the place.  I give it some credit as it was first to find that the pattern was not going to be favorable prior after the 15th, but man...I don't know if I have ever seen it this erratic.  The Pacific is just not cooperating as well.  The other explanation is that very cold air is about to enter the pattern in the d10-15.  That could explain some things.  

From what im reading and researching is that the gfs is having a very tough time handling the forming block in the Northern hemisphere.  No doubt the PNA region is crapping things up but I don't think we go full torch either...

[John1122]

The EPS has been trending towards a + PNA. If that continues and comes to pass, along with the -AO/-NAO that isn't just a recipe for potential, it's normally a near lock for cold/wintry weather. The EPS is also reeling in the set up, unlike the GFS who is kicking the can all over the place from run to run.

[Carvers Gap]

The 12z Euro is what I think is a realistic pattern evolution for the next ten days given the block in place and potential for the Pacific to start lending a hand per John's post above.  It is supported by the CMC and GEPS.  For now....I am tossing all runs of the GFS (unless it verifies....LOL...but which run do we pick?).   

[Carvers Gap]

12 minutes ago, Met1985 said:

From what im reading and researching is that the gfs is having a very tough time handling the forming block in the Northern hemisphere.  No doubt the PNA region is crapping things up but I don't think we go full torch either...

I don't think we will torch(till later in the winter).  But it is definitely having trouble w/ the block IMHO.  The Euro has this inside of d10 now, and it looks remarkably like what ensembles have had for a couple of weeks.  

[John1122]

The CFS is what it is, but it's been "break out the vodka" cold into mid-January.

[John1122]

Euro Control is suppressed and cold with a system that actually gives the Northern Gulf Coast states a decent snowfall.

[Vol4Life]

9 minutes ago, John1122 said:

Euro Control is suppressed and cold with a system that actually gives the Northern Gulf Coast states a decent snowfall.

I’ll take my chances with that at this range!

[John1122]

The EPS continued its trend of Pacific cooperation. Good look in the EPO/PNA areas and great Atlantic too. I'd love to see that establish for a good 4-5 weeks from mid-December into mid to late January. 

[Carvers Gap]

Euro Weeklies, if they are right, show Dec15-Jan5 as our best chance for winter.  Is Cosgrove controlling the Euro Weeklies? -NAO retrogrades(?) to an EPO/PNA ridge.  Eventually, the trough moves out West and doesn't budge.  Looks like '89 without the cold temps from '89.  It does have Christmas as cold.  Nice pattern IF it will verify.  One thing I hold onto is that -NAO patterns tend to resurface later in winter.

[PowellVolz]

The EPS still give us plenty of hope, but the GEFS seems to be leading the way right now.  That said, in the fifteen years we have lived in this house, this is the first time I have seen the leaves off the trees this early.  Completely stripped bare are most of them.  I would guess Mother Nature knows something.

100% agree about the leaves and that was without a major wind event.


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[PowellVolz]

Well, since y'all have brought up the Nature signs...
Birds and squirrels have been behaving like the winter of all winters is coming to us on the plateau. I actually thought about trying to get a picture of them around my house, but never got around to it. 

I’ll add to this… I’m a HVAC tech for Knox Co School. 75% of my A/C units are on the roofs of schools. One of my biggest issues in the late summer into the fall is dealing with wasps nets. They love building in and around roof top units. Not sure what this means exactly but this was the least amount of wasps that I’ve ever seen in the 22 years I’ve been doing this. Might end up being nothing but I thought it’s worth mentioning.


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[PowellVolz]

The 12z Euro follows the CMC lead w/ potential for a wave riding the cold front in the day 9-10 range.  Take w/ a huge grain, but the GFS sort of had it as well.  With the potential for so much cold to be moving into the east, it makes sense for a wave to ride one or more of those cold fronts.

Christmas 2020?


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[PowellVolz]

The EPS has been trending towards a + PNA. If that continues and comes to pass, along with the -AO/-NAO that isn't just a recipe for potential, it's normally a near lock for cold/wintry weather. The EPS is also reeling in the set up, unlike the GFS who is kicking the can all over the place from run to run.

Ryan Hall said yesterday in a video that he thinks we trend to a +PNA. Wouldn’t call him an expert but I’m sure he talks with a lot of people and fishes for their opinions.


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[John1122]

3 hours ago, Carvers Gap said:

Euro Weeklies, if they are right, show Dec15-Jan5 as our best chance for winter.  Is Cosgrove controlling the Euro Weeklies? -NAO retrogrades(?) to an EPO/PNA ridge.  Eventually, the trough moves out West and doesn't budge.  Looks like '89 without the cold temps from '89.  It does have Christmas as cold.  Nice pattern IF it will verify.  One thing I hold onto is that -NAO patterns tend to resurface later in winter.

 

I don't trust any model that quickly breaks down huge blocks. It could happen but they usually jump the gun by a few weeks. 

[Itryatgolf70]

HM or Anthony masiello said we should have one more opportunity at a -nao after this one if he is correct. Main thing to get a pattern that favors winter storms and cold here

[Itryatgolf70]

If the mjo gets out of the IO like the gefs has it currently, we will be in better shape imo. If it's stalls or loops back I'm warm phases, we may be in a world of hurt lol. Let hope it can make it to the western hemisphere 

[John1122]

Torch city on the gfs. It's either going to coup the European/Canadian models or fail in epic fashion. 

[John1122]

At 240 the GFS is +10 to +12, the Canadian is -10 to -12 over the area. 

[Holston_River_Rambler]

Finally got some nice western Pac convection:

But as others have noted the TC in the Indian Ocean is probably skewing the western Pac convection's impact to the overall pattern. 

Long range GFS develops another TC right behind that one and the Euro isn't quite as excited about it, so maybe that has some impact on how each model resolves things downstream? Either way I'm just glad to see some convection developing in the western Pac. 

Both the Euro and GFS have the MJO staying low amplitude in the COD and getting back to 8 in the COD in about 10 days. 

[Carvers Gap]

We are going to see a fairly epic model fail by either the GFS/GEFS or the CMC/GEPS/Euro/EPS in the medium and long range.  

[Holston_River_Rambler]

The Pac looks pretty good (Euro) to much improved (CMC) on the 12z OPs late in their runs. Will it hold? Will it flood? Will severe weather blow us away next week? 

 

[John1122]

16 minutes ago, Holston_River_Rambler said:

The Pac looks pretty good (Euro) to much improved (CMC) on the 12z OPs late in their runs. Will it hold? Will it flood? Will severe weather blow us away next week? 

 

Yep, the GEFS started to cave towards the EPS with a favorable Pacific as well, at least for now. All the major ens models are now on board with it.

[Carvers Gap]

I can’t say that I like a 7-10 delay in a modeled wx pattern.  One winter recently we waited all of Jan/Feb...for what turned out to be a cold front.  The upcoming pattern change at mid latitudes is now set for the 16th.  At one point it was the 11th.  That said, there is decent model agreement this afternoon which is good.  Is that consensus or just one common point on a grid as two ships pass in the night going opposite directions?  We will know soon.  I am optimistic but also a bit more cautious as the colder pattern has been sort of stuck around d10.

[Daniel Boone]

1 hour ago, Carvers Gap said:

I can’t say that I like a 7-10 delay in a modeled wx pattern.  One winter recently we waited all of Jan/Feb...for what turned out to be a cold front.  The upcoming pattern change at mid latitudes is now set for the 16th.  At one point it was the 11th.  That said, there is decent model agreement this afternoon which is good.  Is that consensus or just one common point on a grid as two ships pass in the night going opposite directions?  We will know soon.  I am optimistic but also a bit more cautious as the colder pattern has been sort of stuck around d10.

I am in the same boat as you . Delayed changes always makes me skiddish and less confident. My guess is it will occur but, may be similar to the last cool spell in duration. Could be a cycle until the nina weakens and the MJO can excert more influence in the western PAC to change things up. It is possible due to that prospect alone, mid/late Winter may be better than many believe.

[Carvers Gap]

The cold bias of the CFSv2 (as noted above) is almost always apparent.   The 18z run today was especially good.  The model does have some useful aspects at 500. Beginning of the run -> next ice age.

 

[Daniel Boone]

Speaking of cold biases, the new gfs upgrade tweaked it's somewhat still cold bias... A little too much it appears. 

[Itryatgolf70]

15 hours ago, Holston_River_Rambler said:

Finally got some nice western Pac convection:

But as others have noted the TC in the Indian Ocean is probably skewing the western Pac convection's impact to the overall pattern. 

Long range GFS develops another TC right behind that one and the Euro isn't quite as excited about it, so maybe that has some impact on how each model resolves things downstream? Either way I'm just glad to see some convection developing in the western Pac. 

Both the Euro and GFS have the MJO staying low amplitude in the COD and getting back to 8 in the COD in about 10 days. 

Holston, I'm hoping we see more convection in the western hemisphere eventually over the IO moving forward. Which model or ensemble handles the mjo the best? Just curious 

[John1122]

Starting to get some looks like the last two years with cold banked against the Apps, BN over our region and AN over the Carolinas and Georgia.

[Holston_River_Rambler]

8 hours ago, Itryatgolf70 said:

Holston, I'm hoping we see more convection in the western hemisphere eventually over the IO moving forward. Which model or ensemble handles the mjo the best? Just curious 

I think it depends on which phase it initializes in. A few years ago Webb had some research that if the models initialize it in phase 7, the GFS suite does better than the Euro. But other than that I'm not sure.