2025-2026 ENSO

[GaWx]

30 minutes ago, donsutherland1 said:

In general, a PNA- pattern results in lighter snowfalls in the New York City area and northern Mid-Atlantic. The Boxing Day blizzard is a notable exception and the only KU snowstorm during December when the PNA was negative.

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

[EastonSN+]

3 minutes ago, GaWx said:

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

[GaWx]

16 minutes ago, EastonSN+ said:

 Yeah, way out in fantasyland! This reminds me of this Euro storm from last January in not as far out fantasyland:

  
 While this was gone on the very next run, this turned out to be when the historic 1/21-2/2025 Gulf coast/deep SE winter storm occurred.

[EastonSN+]

8 minutes ago, GaWx said:

 Yeah, way out in fantasyland! This reminds me of this Euro storm from last January I’m not as far out fantasyland:

  
 While this was gone on the very next run, this turned out to be when the historic 1/21-2/2025 Gulf coast/deep SE winter storm occurred.

If the NAO is as strong as predicted, it would favor southern areas. The boxing day blizzard also hit NC hard.

[donsutherland1]

30 minutes ago, GaWx said:

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

I suspect that when it comes to snowstorms in parts of the Southeast, more is involved than the pattern itself. Synoptic details are critical and outweigh the teleconnections. One sees a similar outcome in the spring in the Middle Atlantic region as wave lengths shorten and the state of the teleconnections becomes less important.

[SnowGoose69]

49 minutes ago, donsutherland1 said:

While the AO and NAO are looking good on the latest GEFS, the PNA is not.

It’s going to be a battle in January I think of which one gives in first.  If it’s the NAO winter is probably done for if we assume we get the February most expect we do based on the IOD/ENSO.  If it’s the PNA maybe we can get a crazy 2-3 weeks.  I’d still lean towards February probably being bad but in La Niña to El Niño transition years we’ve seen March sometimes be good  

[donsutherland1]

46 minutes ago, GaWx said:

Hey Don,

 This is somewhat related and something I happened to compile yesterday about big NC snowstorms during -PNAs. First, note that the -PNA for the 2010 storm was only weak (-0.3). Also, what’s interesting about the list below of big NC snows during a -PNA is that only one of the 7 most -PNA 6”+ storms there were during a -NAO! Anyone know why or is this likely just from randomness? It’s a somewhat decent sized sample of 7 and 4 of the 7 had a moderate to strong +NAO as opposed to just a weak +NAO:

6”+ storms since 1950 at GSO and/or RDU: most negative PNA:

-1.1: 2/12-13/2014 (moderate +NAO)
-0.8: 1/22-24/1954 (moderate +NAO)
-0.8: 3/2-3/1960 (neutral NAO)
-0.7: 1/6-7/2017 (moderate +NAO)
-0.5: 3/9/1960 (neutral NAO)
-0.3: 12/26/2010 (moderate -NAO)
-0.3: 2/24-26/2015 (strong +NAO)

Daily PNA:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.pna.index.b500101.current.ascii

Daily NAO:

https://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.nao.index.b500101.current.ascii

 

 

Here's some data for NYC for January and March (1980-2025):

[GaWx]

1 hour ago, donsutherland1 said:

While the AO and NAO are looking good on the latest GEFS, the PNA is not.

 I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill. My GEFS PNA forecasting images for Dec 2021-Jan 2022 displayed that well.

[SnowGoose69]

3 minutes ago, GaWx said:

 I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill.

00 and 97 I think also went pretty strong +PNA I think but can’t recall if they were negative in December or not.  I want to say they were not 

[GaWx]

13 minutes ago, SnowGoose69 said:

00 and 97 I think also went pretty strong +PNA I think but can’t recall if they were negative in December or not.  I want to say they were not 

-Actually, Dec of 1996, indeed, was still another -ENSO strong -PNA that transitioned to a +PNA in Jan after a 1.8+ rise.

-Dec of 1999 had a neutral PNA. So, that isn’t in this group.

*Corrected for typo…Dec of 1999

[donsutherland1]

31 minutes ago, GaWx said:

 I’m very curious to see what happens in Jan with the PNA based on -ENSO strong Dec -PNA analogs like 2021, 2013, 2010, 2008, and 1984 whose Jan PNA all rose 1.8++ from Dec. That’s still well beyond what models can see with any notable degree of skill. My GEFS PNA forecasting images for Dec 2021-Jan 2022 displayed that well.

It will be interesting to see how things evolve. Since 1980, December PNA- cases have been followed by January PNA+ cases. Prior to 1980, December PNA- cases were generally followed by January PNA- cases. It is possible that the less stable PNA state is, at least in part, a result of Arctic amplification.