Mid to long range discussion- 2025

[wncsnow]

Looks like the cold is going to center in the rockies/northwest first and we have a big ridge until the end of the month

[Daniel Boone]

3 hours ago, wncsnow said:

Looks like the cold is going to center in the rockies/northwest first and we have a big ridge until the end of the month

Yep. MJO taking control of the Bus. Blocking may mitigate the Heat in the East by squashing the SER. Hopefully that western trough doesn't dig too deep and help the SER hook up with the -NAO. Models are not showing that but after seeing that happen the last several Years it makes it a possibility.

[wncsnow]

51 minutes ago, Daniel Boone said:

Yep. MJO taking control of the Bus. Blocking may mitigate the Heat in the East by squashing the SER. Hopefully that western trough doesn't dig too deep and help the SER hook up with the -NAO. Models are not showing that but after seeing that happen the last several Years it makes it a possibility.

Exactly. That's my main concern and it's incredibly hard to get rid of 

[wncsnow]

Long range continues to look generally warm on ops and ensembles. When does it flip?

[calculus1]

Doesn’t need to flip until December, at the earliest. No sense wasting all the good teleconnections in November, when most of us can’t get snow anyway, despite the upper air patterns.


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[PackGrad05]

2 minutes ago, calculus1 said:

Doesn’t need to flip until December, at the earliest. No sense wasting all the good teleconnections in November, when most of us can’t get snow anyway, despite the upper air patterns.


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Agreed.  I'll take it in late December/all of January.

[Met1985]

1 hour ago, wncsnow said:

Long range continues to look generally warm on ops and ensembles. When does it flip?

Honestly a transition the first of December would be best climatologically speaking. 

[SUNYGRAD]

[WinstonSalemArlington]

Eww

[wncsnow]

I agree that a perfect pattern now would likely mean no snow outside the mountains but patterns repeat themselves and the one the next few weeks looks very Nina ish

[Daniel Boone]

Interesting development in the North Atlantic. SST'S becoming favorable for a -NAO this Winter. 

https://x.com/Aigle_e/status/1989420648234668098?s=20

[NorthHillsWx]

Worried about SER this winter. I’ve seen this tune before it gets going and PNA continues to screw us until a one week post frontal cold snap in January especially in a La Niña year. This setup is tough to burn in the SE especially when it’s already rearing its head. Could flip, but color me concerned with PNA trending negative. At least it’s mid November not mid December heading into a screwball pattern but winters where the SER gets going and Pacific trends to hell tend to have repeat performances through the season and being a Nina year It doesn’t feel great seeing this pattern show up 

[eyewall]

3 hours ago, NorthHillsWx said:

Worried about SER this winter. I’ve seen this tune before it gets going and PNA continues to screw us until a one week post frontal cold snap in January especially in a La Niña year. This setup is tough to burn in the SE especially when it’s already rearing its head. Could flip, but color me concerned with PNA trending negative. At least it’s mid November not mid December heading into a screwball pattern but winters where the SER gets going and Pacific trends to hell tend to have repeat performances through the season and being a Nina year It doesn’t feel great seeing this pattern show up 

I was hoping this would be the year for a 6 inch plus event but I am not so optimistic now.

[NorthHillsWx]

58 minutes ago, eyewall said:

I was hoping this would be the year for a 6 inch plus event but I am not so optimistic now.

At least we’re not burning prime climo but I am very concerned given it being Nina and pacific heading to crap. All this blocking and +PNA we’ve had has still managed to produce a “heatwave” and northern storm track so losing blocking and pacific turning bad does not bode well 

[GaWx]

4 hours ago, NorthHillsWx said:

Worried about SER this winter. I’ve seen this tune before it gets going and PNA continues to screw us until a one week post frontal cold snap in January especially in a La Niña year. This setup is tough to burn in the SE especially when it’s already rearing its head. Could flip, but color me concerned with PNA trending negative. At least it’s mid November not mid December heading into a screwball pattern but winters where the SER gets going and Pacific trends to hell tend to have repeat performances through the season and being a Nina year It doesn’t feel great seeing this pattern show up 

 I just looked up -ENSO winters with a -PNA in Dec to see how often it went to a +PNA in Jan. In what winters did this occur?

-1954-5: -0.52 to +0.40

-1962-3: -0.08 to +0.58

-1983-4: -0.31 to +0.97

-1984-5: -1.60 to +1.63

-1996-7: -1.23 to +0.63

-1998-9: -0.09 to +0.16

-2008-9: -1.41 to +0.61

-2010-11: -1.78 to +1.29

-2012-3: -1.01 to +0.55

-2013-4: -0.86 to +0.97

-2016-7: -0.35 to +0.28

-2021-2: -2.56 to +1.01

-2022-3: -0.66 to +0.22

 So, although it wasn’t common from 1954-5 through 1971-2, when only 2 of 9 (22%) switched, here’s something that just blew my mind:

-ALL 11 -ENSO -PNA Decs since 1983-4 switched to +PNA Jans (listed above)!

-These 11 averaged +0.76 in January!

-Now, check out the -ENSO Jan PNAs since 1983-4 that had a +PNA in Dec:

1) 1985-6 went from +1.39 to +0.97

2) 1988-9 went from +0.63 to -0.72

3) 1995-6 went from +0.92 to -0.02

4) 1999-00 went from +0.21 to -0.82

5) 2000-01 went from +1.23 to +1.51

6) 2001-2 went from +0.56 to -0.04

7) 2005-6 went from +1.38 to -0.43

8) 2007-8 went from +0.14 to -0.32

9) 2011-2 went from +0.36 to +0.60

10) 2017-8 went from +0.89 to +0.40

11) 2020-1 went from +1.58 to +0.19

12) 2024-5 went from +1.70 to +1.05

 -So, for these 12 -ENSO Decs since 1983-4 with a +PNA, only 50% also had a +PNA in Jan.

-So, since 1983-4, whereas only 50% of the 12 -ENSO Decs with a +PNA also had a Jan +PNA, 100% of the 11 -ENSO Decs with a -PNA in Dec went to a +PNA in Jan! Thus, having a -PNA in Dec during -ENSO since 1983-4 has, if anything, meant a big increase in the chance for a +PNA in Jan whether random or not! I didn’t know this til just now.

Link to monthly PNAs back to 1950:

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table