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.