2025-2026 ENSO

[bluewave]

3 hours ago, 40/70 Benchmark said:

I think there is some value in honing in on how much temperature maxes have warmed, since I don't think the warmer mins are as detrimental to snowfall.

The main detriment to snowfall in general for the I-95 corridor since 18-19 has been the warm storm tracks. So while this winter averaged 34.8° in NYC, the 11 days on which .25+ of precipitation fell averaged 41.0°.

For 50”+ snowfall seasons and La Niña background NYC needs to average closer to 32.0° and have cold storm tracks and storm days when the bulk of the precipitation falls.

Even during the warmer winters of 15-16, 16-17, 17-18, and 20-21,the colder storm tracks and storm days allowed NYC to finish in the respectable 30-40” range for snowfall. But the lack of cold for a DJF average near 32.0° was too warm to go 50”+.

Since 18-19 we have had both a warm background pattern and warm storm tracks. So this is why the 7 year snowfall totals have been at record low levels. I am hoping for the remainder of the 2020s we can see some bounce off these extreme low values. But expecting a repeat of 2010-2018 is probably a very low probability outcome absent some major volcanic event.

[snowman19]

This is shaping up to be the strongest -IOD event since 16-17

[mitchnick]

I noticed over in the MA Medium Range thread that the Euro weeklies have been getting progressively cooler as the forecast periods approach.

Interestingly, while searching for any tidbits for early winter thoughts on YouTube, I  found a September forecast from Bam Weather. It looks like I'm not the only one who noticed the changes on the weeklies. According to Bam, both the regular Eps products and Gefs have been too warm lately. Otoh, the EPS AI has been much better. 

I put the link to the video below and it's got some decent info in addition to the comments on the EPS AI. Take a look if you get a chance. More importantly, the performance of the EPS AI should probably be followed through the Fall to see if it holds any edge come winter.

 

[Stormchaserchuck1]

^Yeah the Great Lakes trough for around 9/4 was not even on models 7-10 days ago. Now it's expected to be -400dm and actually closes off for a little while. I've been noticing weak projections on ensemble means >11 days out. I wonder why that is. 

[Stormchaserchuck1]

14 hours ago, snowman19 said:

@Stormchaserchuck1

Actually the cold waters off of New Foundland have turned my N. Atlantic SST indicator for Winter NAO negative on the daily. Of course, it's an average of May-Sept, but Erin really did cool that -NAO area a bit.. if you want to make a correlation between ACE and following Winter NAO, like a lot of people do... 

It's been pretty rare lately to have that whole area from the Davis strait to N. Atlantic below average, but there has been persistent -H5 over the region this Summer. I've found that since 2012 it correlates with a following Winter ridge at 90N. 

[snowman19]

41 minutes ago, Stormchaserchuck1 said:

^Yeah the Great Lakes trough for around 9/4 was not even on models 7-10 days ago. Now it's expected to be -400dm and actually closes off for a little while. I've been noticing weak projections on ensemble means >11 days out. I wonder why that is. 

EURO/EPS hasn’t been what it used to be for awhile now

@Stormchaserchuck1 In regards to your last post: 

“Actually the cold waters off of New Foundland have turned my N. Atlantic SST indicator for Winter NAO negative on the daily. Of course, it's an average of May-Sept, but Erin really did cool that -NAO area a bit.. if you want to make a correlation between ACE and following Winter NAO, like a lot of people do... 

It's been pretty rare lately to have that whole area from the Davis strait to N. Atlantic below average, but there has been persistent -H5 over the region this Summer. I've found that since 2012 it correlates with a following Winter ridge at 90N.”

The last time I remember the North Atlantic being this cold was 2013-14

[Stormchaserchuck1]

^I don't think it's going to be as much of a blowout +NAO Winter as we previously thought, but there is still strong tendency for us to pattern change 10 days to a few weeks after a cold period, that has been in effect for a while now. I don't see 13-14 style cold happening this Winter. -NAO/-AO/+PNA hasn't been staying in a strong state for more than a short time. Last Feb it went from -31F in Valentine, Nebraska to 60s a few days later. Some places had a 3-day change of 100 degrees. It's not sustaining. 

[Stormchaserchuck1]

I saw bluewave posted in the climate change forum, The Arctic circle trough that I had been tracking ended up maxing out at 4980dm yesterday, which is the lowest 500mb height on record in the Northern Hemisphere for August. It's akin to the 10" of snow that fell in Florida last Winter happening again. 

[snowman19]

10 hours ago, Stormchaserchuck1 said:

^I don't think it's going to be as much of a blowout +NAO Winter as we previously thought, but there is still strong tendency for us to pattern change 10 days to a few weeks after a cold period, that has been in effect for a while now. I don't see 13-14 style cold happening this Winter. -NAO/-AO/+PNA hasn't been staying in a strong state for more than a short time. Last Feb it went from -31F in Valentine, Nebraska to 60s a few days later. Some places had a 3-day change of 100 degrees. It's not sustaining. 

13-14 was one of the strongest ++AO/++NAO winters in history, I believe it was second only to the 88-89 winter. It was 100%, all Pacific driven. We went into a Victoria mode PDO (psuedo +PDO) and had relentless strong +PNA/-EPO/-WPO all winter long. The PAC side behaved like an El Niño despite the cold-neutral ENSO that was in place

[mitchnick]

8 hours ago, Stormchaserchuck1 said:

I saw bluewave posted in the climate change forum, The Arctic circle trough that I had been tracking ended up maxing out at 4980dm yesterday, which is the lowest 500mb height on record in the Northern Hemisphere for August. It's akin to the 10" of snow that fell in Florida last Winter happening again. 

Stop reading the CC forum or you'll go blind!

Seriously, Euro weeklies have winds at 10mb dying down if that forecast can be trusted. 

[snowman19]

@GaWx

As expected, geomag is picking up again
 
 

[GaWx]

1 hour ago, snowman19 said:

@GaWx

As expected, geomag is picking up again
 
 

2025 08 22 2025.640  55   7.1  27  31
2025 08 23 2025.642  75   6.9  25  31
2025 08 24 2025.645 109   8.7  34  41
2025 08 25 2025.648 142  15.2  37  45
2025 08 26 2025.651 192  21.8  36  40
2025 08 27 2025.653 211  23.0  26  33
2025 08 28 2025.656 204  15.8  23  29
2025 08 29 2025.659 209  24.9  31  34
2025 08 30 2025.662 196  18.9  24  30
2025 08 31 2025.664 195  12.7  18  21

[GaWx]

 Per Joe Bastardi yesterday in the free video, this is and will likely end up being the quietest Labor Day weekend for the globe as a whole tropically (not Atlantic specifically as 2024, for one, was equally quiet) of most of our lifetimes. There was just an Invest in the EPAC and the remnants of a TD in SE Asia. That was it, which is fascinating!

[snowman19]

1 hour ago, GaWx said:

 Per Joe Bastardi yesterday in the free video, this is and will likely end up being the quietest Labor Day weekend for the globe as a whole tropically (not Atlantic specifically as 2024, for one, was equally quiet) of most of our lifetimes. There was just an Invest in the EPAC and the remnants of a TD in SE Asia. That was it, which is fascinating!

If I had to pick out the things in the PAC that are different from last year at this time besides the obvious (-IOD, earlier developing La Niña, -PMM, -AAM), it would be the total lack of a parade of recurving tropical cyclones and extratropical systems coming off the coast, upwelling and cooling the marine heatwave around Japan like we had last year.