Winter 2026-2027. Historic Potential

[Bob Chill]

2 hours ago, Stormchaserchuck1 said:

Yeah, something interesting is the CPC NAO index has run significantly higher in the wintertime than what the 500mb composite has looked like. We've had all but 1 +NAO Winters since 10-11. And that one was -0.21. 

Yea, cpc uses 1000mb surface pressure patterns for its numerical index calc which throws me off at times too because we always look at 500mb height progs. Surface pressure does correlate to 500mb but things get muddy in that dept. Some of which is due to domain space size. I dont worry too much about the numerical index when 500mb looks tasty lol

[Stormchaserchuck1]

It certainly feels like Fall the past 2 days. 60s in the evening both times. It seems like since 2024 every Summer has been hot in the beginning then cool at the end. 

Another -400dm low over the Arctic today. Again, every May-Sept has had that pattern 60-90N: 2024, 2025, 2026. 

July-Aug the wettest months of the year again, matching the 2017-2025 pattern. 

[stormy]

1 hour ago, Stormchaserchuck1 said:

It certainly feels like Fall the past 2 days. 60s in the evening both times. It seems like since 2024 every Summer has been hot in the beginning then cool at the end. 

Another -400dm low over the Arctic today. Again, every May-Sept has had that pattern 60-90N: 2024, 2025, 2026. 

July-Aug the wettest months of the year again, matching the 2017-2025 pattern. 

May was my wettest month. July and August have been dry.

[Stormchaserchuck1]

1 hour ago, stormy said:

May was my wettest month. July and August have been dry.

My area has been extremely wet. I think in the eastern 40% of US it has matched the trend

Everyone is saying it's because of El Nino, I think it's a 10-year thing happening. The Fall will be a better indicator of how wet the Nino STJ is. 

[stormy]

9 hours ago, Stormchaserchuck1 said:

My area has been extremely wet. I think in the eastern 40% of US it has matched the trend

Everyone is saying it's because of El Nino, I think it's a 10-year thing happening. The Fall will be a better indicator of how wet the Nino STJ is. 

Thanks Chuck!

During July in Augusta County,  I only received 62% of normal rainfall.   During August, I have received 66% of normal thru 8-20.

[Terpeast]

9 hours ago, Stormchaserchuck1 said:

My area has been extremely wet. I think in the eastern 40% of US it has matched the trend

Everyone is saying it's because of El Nino, I think it's a 10-year thing happening. The Fall will be a better indicator of how wet the Nino STJ is. 

Yes its too early to attribute warm season patterns to el nino, the coupling shows up better in the fall as the NH cools

[Maestrobjwa]

24 minutes ago, Terpeast said:

Yes its too early to attribute warm season patterns to el nino, the coupling shows up better in the fall as the NH cools

Now did I understand correctly that developing niño summers have more severe weather?

[Terpeast]

1 hour ago, Maestrobjwa said:

Now did I understand correctly that developing niño summers have more severe weather?

I’m not sure, but I’ve always thought that el ninos have more influence on summers the following year after +enso develops. Could be wrong though

[Eskimo Joe]

4 hours ago, Terpeast said:

Yes its too early to attribute warm season patterns to el nino, the coupling shows up better in the fall as the NH cools

As a pure snow and cold weenie, what benchmarks should we be looking for and when should they start to emerge that would indicate this could be a legit winter?

[frd]

1 hour ago, Eskimo Joe said:

As a pure snow and cold weenie, what benchmarks should we be looking for and when should they start to emerge that would indicate this could be a legit winter?

I would speculate - 

the PDO starting to rise in Sept and continuing to rise at a decent clip in Oct./Nov.

A weaker early season PV accompanied by a general cycle trend down with the AO all through the Fall. 

Above normal North American Snow extent through Sept to Dec.  

Signs that might indicate -NAO during the winter, I defer to Chuck on this one  

Watch the East based Nino regions, could overwhelm all 3 above items. 

 

 

[Terpeast]

14 minutes ago, frd said:

I would speculate - 

the PDO starting to rise in Sept and continuing to rise at a decent clip in Oct./Nov.

A weaker early season PV accompanied by a general cycle trend down with the AO all through the Fall. 

Above normal North American Snow extent through Sept to Dec.  

Signs that might indicate -NAO during the winter, I defer to Chuck on this one  

Watch the East based Nino regions, could overwhelm all 3 above items. 

 

 

frd did a good job covering what to watch for.

Only thing I would add is the STJ. If we get a decent amount of coastal storms, and we’re AN in precipitation from Sept-Nov, that’s another sign. 

[Terpeast]

Also i wouldn’t be surprised to see an outrageously warm winter month, talking +10. I’m hoping that is December, willing to sacrifice that month for a better Jan-Feb

[CAPE]

1 hour ago, Terpeast said:

Also i wouldn’t be surprised to see an outrageously warm winter month, talking +10. I’m hoping that is December, willing to sacrifice that month for a better Jan-Feb

The CFS has been remarkably consistent in suggesting Feb and March will hold the best chance for cold and a big winter storm. Dec h5 pattern looks very mild with PAC puke look, and Jan might trend colder towards the end. Not surprising that the latter part of winter has the best potential to deliver when the Nino may relax a bit/ max SST anomalies shift more westward. All fwiw ofc.

Pretty nice looks here. Should be just cold enough a time or two as the key features shift/ align in a favorable configuration.

 

[RIC_WX]

1 hour ago, Terpeast said:

Also i wouldn’t be surprised to see an outrageously warm winter month, talking +10. I’m hoping that is December, willing to sacrifice that month for a better Jan-Feb

I have this feeling too, and if you think about it, the warmer December is the colder JFM can be and still the winter can average normal to slightly above overall.  I am almost ready to root for this as it feels close to a lock anyway.

[Stormchaserchuck1]

2 hours ago, frd said:

I would speculate - 

the PDO starting to rise in Sept and continuing to rise at a decent clip in Oct./Nov.

A weaker early season PV accompanied by a general cycle trend down with the AO all through the Fall. 

Above normal North American Snow extent through Sept to Dec.  

Signs that might indicate -NAO during the winter, I defer to Chuck on this one  

Watch the East based Nino regions, could overwhelm all 3 above items. 

 

 

October NAO is interestingly inverse to the Winter (DJFM)! It's the only month of the year that has an opposite correlation. 

October is also the highest month of PDO correlation to US pattern. The Pacific 500mb in October is a big indicator to see which is winning the battle - El Nino vs -PDO!

Of course we've had 6 straight months of -PNA, and Aug is looking to come in around 0.0. I mean, if that continues it will be interesting to see what actually happens in the Winter (basic Nino pattern is not a given). 

[Stormchaserchuck1]

1 hour ago, CAPE said:

The CFS has been remarkably consistent in suggesting Feb and March will hold the best chance for cold and a big winter storm. Dec h5 pattern looks very mild with PAC puke look, and Jan might trend colder towards the end. Not surprising that the latter part of winter has the best potential to deliver when the Nino may relax a bit/ max SST anomalies shift more westward. All fwiw ofc.

Pretty nice looks here. Should be just cold enough a time or two as the key features shift/ align in a favorable configuration.

 

CFS sucks as a model bro. Why would we have strong Winter -NAO when we haven't had it in 14 years, we have +QBO, and Descending Solar (favors +nao 1-5 years after Max)? I mean I could be wrong of course but I remember last 2 years the CFS was consistently showing like -20F monthly anomalies in the NW, US for the Winter and they ended up being solidly above average lol

[CAPE]

50 minutes ago, Stormchaserchuck1 said:

CFS sucks as a model bro. Why would we have strong Winter -NAO when we haven't had it in 14 years, we have +QBO, and Descending Solar (favors +nao 1-5 years after Max)? I mean I could be wrong of course but I remember last 2 years the CFS was consistently showing like -20F monthly anomalies in the NW, US for the Winter and they ended up being solidly above average lol

Maybe we are due? And the CFS doesnt have a strong -NAO for the entire winter- it develops later in winter. We have had well timed-NAO periods in recent winters that have contributed to snowstorms in our area. We don't need a wall to wall NA block. See Jan 2016.

[Stormchaserchuck1]

41 minutes ago, CAPE said:

Maybe we are due? And the CFS doesnt have a strong -NAO for the entire winter- it develops later in winter. We have had well timed-NAO periods in recent winters that have contributed to snowstorms in our area. We don't need a wall to wall NA block. See Jan 2016.

Here is the NAO streak we have going in February

2014 1.34
2015 1.32
2016 1.58
2017 1.00
2018 1.58
2019 0.29
2020 1.26
2021 0.14
2022 1.68
2023 0.92
2024 1.09
2025 1.60
2026 0.68

Will this year be a -1.5? It could be, but I wouldn't bet the house on it. 

[Ji]

Here is the NAO streak we have going in February
2014 1.34
2015 1.32
2016 1.58
2017 1.00
2018 1.58
2019 0.29
2020 1.26
2021 0.14
2022 1.68
2023 0.92
2024 1.09
2025 1.60
2026 0.68
Will this year be a -1.5? It could be, but I wouldn't bet the house on it. 

Feb has been atrocious lately. Yikes

[Ji]

The CFS has been remarkably consistent in suggesting Feb and March will hold the best chance for cold and a big winter storm. Dec h5 pattern looks very mild with PAC puke look, and Jan might trend colder towards the end. Not surprising that the latter part of winter has the best potential to deliver when the Nino may relax a bit/ max SST anomalies shift more westward. All fwiw ofc.
Pretty nice looks here. Should be just cold enough a time or two as the key features shift/ align in a favorable configuration.

 

We are due for a 90 degree day in early December. This is the year

[Stormchaserchuck1]

11 minutes ago, Ji said:

Feb has been atrocious lately. Yikes

Not to mention the record -PNA streak we had going 18-25 Feb-March until last year

I mean Feb has been bad but look at March compared to the 91-20 average over the last 7 years

Last March had a +2.92 NAO, the 2nd highest in all monthly records for all months of the year since 1948. 

At least we can say it's been because of bad oscillations, not everything neutral and some unknown reason. 

[Ephesians2]

Is that ridge from NW of Hawaii to Japan normal for a Nino? Or is that due to the PDO and really warm water in that area?

[Ji]

Not to mention the record -PNA streak we had going 18-25 Feb-March until last year

I mean Feb has been bad but look at March compared to the 91-20 average over the last 7 years

Last March had a +2.92 NAO, the 2nd highest in all monthly records for all months of the year since 1948. 
At least we can say it's been because of bad oscillations, not everything neutral and some unknown reason. 

After pd weekend I lose interest in winter but didn’t realize March has been so poor too. Our winter now is basically January

[Eskimo Joe]

16 hours ago, Terpeast said:

Also i wouldn’t be surprised to see an outrageously warm winter month, talking +10. I’m hoping that is December, willing to sacrifice that month for a better Jan-Feb

That would be hellacious. 

10 hours ago, Ji said:

We are due for a 90 degree day in early December. This is the year

Heat Advisories for Christmas!

[ravensrule]

11 minutes ago, Eskimo Joe said:

That would be hellacious. 

Heat Advisories for Christmas!

Seeing @Ji in his Speedo will be just what the grinch ordered. 

[bncho]

saw these graphics on twitter and it’s pretty interest how cold the CFS thinks January and especially February will be considering average 2m temps are like 38-41F for them

[bncho]

Last winter reanalysis for reference 

[Terpeast]

5 minutes ago, bncho said:

 

That would be the coldest feb in decades. Maybe historic. Overdone probably 

[bncho]

4 minutes ago, Terpeast said:

That would be the coldest feb in decades. Maybe historic. Overdone probably 

Yea that’s what I was thinking, but even if we get a third of that cold we are in business february

[GaWx]

2 hours ago, bncho said:

saw these graphics on twitter and it’s pretty interest how cold the CFS thinks January and especially February will be considering average 2m temps are like 38-41F for them

 

 Thanks for posting these. I see these are based on just one run, 8/22/26 at 0Z, as opposed to being based on a mean of multiple runs. To compare, the 3 day/12 run means on Tropical Tidbits and even the 10 day/40 run means directly from the CFSv2 are of limited value, especially considering how jumpy they often are from one run to the next due to essentially no forecasting value that far out.

 So, this X-post being based on just one run is essentially of no value.

 For example, here are the last two runs from WxBell for Feb ‘27:

6Z 8/23/26: cold in E, warm in W

 

0Z 8/23/26: nearly the exact opposite!

 Here’s that x-post’s Feb. ‘27 map again:

 To help emphasize how laughably frigid this post’s Feb CFSv2 map is in the E US, check out how much colder it is vs the record coldest (in degrees F):

-DC ~20 vs coldest 24.6 (1934)

-Richmond ~22 vs coldest 28.2 (1934)

-Chattanooga ~19 vs coldest 33.8 (1958)

-Atlanta ~25F vs coldest 34.4 (1895)

Cities’ coldest from here:

https://www.weather.gov/wrh/climate

@Terpeast