Mid-Long Range Discussion 2026

[suzook]

2 hours ago, GaWx said:

The 12Z EPS for SAV has gotten my attention for the small chance of Sun AM light snow/flurries, which in this area would be a big deal due to the relative rarity being that most winters get nothing, not even a T. We got nothing Feb 2018 through Dec 2024.
 

 My expectations, especially for measurable, are low due to climo, it being pretty dry overall with member qpf progs being light, and marginal temps.

So, fwiw, here are some 12Z EPS images: ~25% of members have snow, which is notably high:

 

Mean: 0.2”, notable for here:

As much as I would like to believe this, it's been dry as f here. Every precip chance just fizzles out. I'm just thinking it will be dry

[Coach McGuirk]

Late January looks interesting. 

[Jimbo!]

I see potential near 24-26 and I’d bet it does a rare s trend. My surgery on the 14th got rescheduled til the 26th cause surgeon was sick.


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[BornAgain13]

1 hour ago, BooneWX said:

Funny you say that: the NBM’s footprint is further west tonight than some of the snowier OPs we saw at 18z. It would favor Delmarva southwest through the Virginia/NC piedmonts into western NC.

U have a map of the NBM?

[GaWx]

From Don Sutherland:

Yes, the PNA is far more important to Atlanta's January snowstorms than the NAO. Since 1950, the PNA was positive for 84.2% of Atlanta's 1" or greater snowstorms. The NAO was negative for 63.2% of such storms.

 I’ll add that that these Jan snowstorms were during La Niña:

Dates……PNA…….NAO

1/15-17/1965…+1.191…+0.438

1/6-8/1996…+0.289…-0.640

1/19/2008…+0.430…+0.287

1/9-10/2011…-0.223…-0.524

1/16-17/2018…+0.101…+1.430

1/10/2025…+1.105…-1.208

 

 So, just for the six 1”+ Jan storms during La Nina:

-5 of the 6 PNAs were >0 and the lowest was only down to -0.223. Avg PNA was +0.5

-In contrast, 3 of the 6 NAOs were positive with one of them strongly positive. The avg NAO was near 0/neutral.

—————

 The 1/18/26 potential SE snowstorm looks like it will be during a moderate MJO phase 6, a strong +PNA, a neutral to moderately -AO, slightly + to neutral NAO, -WPO, and a very strong -EPO, which may be sub -3 then.

 So, the highlight is strong +PNA/-EPO during a phase 6.

[BooneWX]

U have a map of the NBM?

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[Daniel Boone]

55 minutes ago, GaWx said:

From Don Sutherland:

Yes, the PNA is far more important to Atlanta's January snowstorms than the NAO. Since 1950, the PNA was positive for 84.2% of Atlanta's 1" or greater snowstorms. The NAO was negative for 63.2% of such storms.

 I’ll add that that these Jan snowstorms were during La Niña:

Dates……PNA…….NAO

1/15-17/1965…+1.191…+0.438

1/6-8/1996…+0.289…-0.640

1/19/2008…+0.430…+0.287

1/9-10/2011…-0.223…-0.524

1/16-17/2018…+0.101…+1.430

1/10/2025…+1.105…-1.208

 

 So, just for the six 1”+ Jan storms during La Nina:

-5 of the 6 PNAs were >0 and the lowest was only down to -0.223. Avg PNA was +0.5

-In contrast, 3 of the 6 NAOs were positive with one of them strongly positive. The avg NAO was near 0/neutral.

—————

 The 1/18/26 potential SE snowstorm looks like it will be during a moderate MJO phase 6, a strong +PNA, a neutral to moderately -AO, slightly + to neutral NAO, -WPO, and a very strong -EPO, which may be sub -3 then.

 So, the highlight is strong +PNA/-EPO during a phase 6.

Just looking at MJO Charts one would expect a mild Pattern in the East. Goes to show other Drivers sometimes dictate or throw the MJO effects off kilter. Even the location of La nina apparently according to some research. 

[Daniel Boone]

12 minutes ago, BooneWX said:

.

It's a blend of the Model's as most know as it's pretty obvious. I don't know how many are used or which one's to come up with the Average of them all. It's been awhile since I was told by the NWS . They just explained it and said it's the one they use.

I don't think any Model's are given more weight than the others. If the better Model is showing 10" for a given area while 2 of the worst are showing zilch, the printout is going to be very low and may be way off.

   So, it's overall a good Idea Model. You get the average of the Consensus so to speak but, it can sometimes be way off because of what I mentioned above. 

[GaWx]

19 minutes ago, Daniel Boone said:

Just looking at MJO Charts one would expect a mild Pattern in the East. Goes to show other Drivers sometimes dictate or throw the MJO effects off kilter. Even the location of La nina apparently according to some research. 

 Actually, I did a study recently that surprisingly showed that Jan phase 6 in the SE (using GSP as a representative) has had a mix with a bit more cold vs warm phase 6 Jan periods. Examples of cold during La Niña in Jan:

1975 (8 BN), 1976 (9 BN during a long period of 13 days), 2000 (4 BN), 2011 (7 BN during a long period of 12 days), 2022 (9 BN), and 2025 (5 BN). 
 
 There were some mild Jan phase 6 periods during La Niña also like 1989 (+8) and 2008 (+8) although those two were only 3 days long each.

Keep in mind though that the current phase 6 started off mild. So, it remains to be seen how cold it will end up overall as it’s progged to last through ~Jan 21st.

 

[Daniel Boone]

4 minutes ago, GaWx said:

 Actually, I did a study recently that surprisingly showed that Jan phase 6 in the SE (using GSP as a representative) has had a mix with a bit more cold vs warm phase 6 Jan periods. Examples of cold during La Niña in Jan:

1975 (8 BN), 1976 (9 BN during a long period of 13 days), 2000 (4 BN), 2011 (7 BN during a long period of 12 days), 2022 (9 BN), and 2025 (5 BN). 
 
 There were some mild Jan phase 6 periods during La Niña also like 1989 (+8) and 2008 (+8) although those two were only 3 days long each.

Yes. That's what I was referring to irt research. I'd saw a thing or two on where you had did that. Was that dependant on La nina location Larry ? Im thinking that is what was batted around as the possible reason.

[GaWx]

1 minute ago, Daniel Boone said:

Yes. That's what I was referring to irt research. I'd saw a thing or two on where you had did that. Was that dependant on La nina location Larry ?

I didn’t break it down by La Niña location.

[CaryWx]

0z gfs bringing some goods

[Daniel Boone]

4 minutes ago, GaWx said:

I didn’t break it down by La Niña location.

Can you research that and see if there's a connection ?

[SnowDawg]

I swear…. I am not emotionally mature enough to handle it snowing in deep south GA for a 2nd year in a row while I get nothing. Please save me NW trend lol.

[gamecockinupstateSC]

[GaWx]

16 minutes ago, Daniel Boone said:

Can you research that and see if there's a connection ?

I don’t think I can because I don’t have a list of La Niña by location. If you can provide that, I can break it down.

[Daniel Boone]

2 minutes ago, GaWx said:

I don’t think I can because I don’t have a list of La Niña by location. If you can provide that, I can break it down.

Ok. If we can find whether it was east west or basin wide those cold Year's. 

[Daniel Boone]

From what I can tell, they were predominantly East based Larry ,Just running off memory. Maybe you can find more clarity on that. Also, blocking looks to of been in place. I remember the long cold stretch in 2011 well. Incidentally, as I'm sure you know, that was a fairly strong Nina. Strong Blocking that Winter. 

[GaWx]

 The 0Z GFS is giving >1” of snow to this area on Jan 18th, which would be the second straight Jan with measurable snow. That’s never happened since official records started 150 years ago. The closest thing to that would be Jan of 1921’s 0.5” and Jan of 1922’s major icestorm. And then the glorious Jan of 1977 had two.

 Climo always says bet against measurable wintry precip here as no more than 25% of winters have had that. 

 OTOH, there has been increased ensemble support.

But OTOH, there’s the typical NW trend when there’s no -NAO, which would work against it.
 

 So, keeping all of that in mind, I’m taking this with a grain (2m temps are also progged to be marginal as of now with 34-35 being the coldest):

[GaWx]

0Z GEFS has had a large increase: