2025-2026 ENSO

[michsnowfreak]

4 minutes ago, PhiEaglesfan712 said:

Baltimore had 80 inches of snow in 2009-10 (might I add this total was reached by 2/15... the temp reached 90 by 4/6), and 0.2 inches of snow in 2022-23.

PHL had 78.7 inches of snow in 2009-10, and trace in 1972-73, as well as 0.3 inches of snow in 2019-20 and 2022-23, and 0.8 inches of snow in 1997-98.

Like I said. Crazy. In the entire 152-year climate record, the most for Detroit was 94.9" in 2013-14 & the least 12.9" in 1936-37, one of the dustbowl winters.

[snowman19]

19 hours ago, donsutherland1 said:

It will be interesting to see how this plays out. During the 2016-2017 weak La Niña event, which collapsed in January, there was also a powerful WWB. Indeed, the SOI plunged to -33.54 on January 19th. It remains to be seen if that WWB will actually be rivaled, much less surpassed. The 2016-17 La Niña had two days in January where the SOI was -30 or below. No other La Niña event had even one. However, daily SOI values only go back to 1991.
February 2017 was truly a "torch" in much of the eastern half of the U.S. I'm not expecting anything along those lines. But the idea that a cold or very cold outcome for February is a "slam dunk" following a powerful January WWB should it occur as modeled, is probably too simplistic. As noted above, 2016-17 saw the opposite outcome.
A rapidly weakening La Niña would become less of a factor in influencing patterns. As that happens, other variables, many of which cannot be forecast at current lead times, will gain importance. This competition among variables could lead to large variability on a week-to-week basis. The changeable outcome on the extended range of the ECMWF weeklies may be offering an early hint of that variability. For now, at least based on past late-stage weak La Niña events, the best chances for monthly cold anomalies likely are the Plains States, Great Lakes Region, and eastward into the Northeast. Cold anomalies from the Southwest eastward through the Southeast would be far less likely. 

The 16-17 Niña matched this one pretty close….weak Niña, very strong -IOD that peaked in the fall, then a rapid, total Niña collapse in January, 2017 with a massive WWB and a record SOI crash (remains to be seen if this one has the big SOI crash and record WWB comparable to that January)…. @GaWx @PhiEaglesfan712

[snowman19]

@40/70 Benchmark I’m assuming you disagree with Eric’s take that there’s going to be a big SPV strengthening then coupling with the troposphere leading to +AO/+NAO late winter into spring?
 

 

 

 

 

[so_whats_happening]

1 hour ago, michsnowfreak said:

See this is crazy to me! 30" storm - 2 2 foot storms in a week - 0.9" for an entire season....all in the same place!

Yea it is a fascinating climo around here. 

1 hour ago, PhiEaglesfan712 said:

Baltimore had 80 inches of snow in 2009-10 (might I add this total was reached by 2/15... the temp reached 90 by 4/6), and 0.2 inches of snow in 2022-23.

PHL had 78.7 inches of snow in 2009-10, and trace in 1972-73, as well as 0.3 inches of snow in 2019-20 and 2022-23, and 0.8 inches of snow in 1997-98.

Yea I was on shift when we got that .2" lol did not expect the season to be just horrid. Unfortunately Baltimore may have some snow total issues for storms in the future. We are no longer measuring as weather observers it is across the airfield now, measured by EMS.

[GaWx]

27 minutes ago, snowman19 said:

@40/70 Benchmark I’m assuming you disagree with Eric’s take that there’s going to be a big SPV strengthening then coupling with the troposphere leading to +AO/+NAO late winter into spring?
 

 

 

 

 

 I’m not disputing Eric, but it seems somewhat counterintuitive that the cold E US is still favored in Feb even with a +AO/+NAO. Wx history is so fascinating!

[GaWx]

 I just counted the # of days in Jans 1975-89 by MJO phase: there are stark differences vs Jans 2011-25 as was suspected:

# of days per phase Jans 1975-89 (465 total days)/% of Jan days per phase

1: 39 (8%)
2: 67 (14%)
3: 67 (14%)
4: 57 (12%)
5: 46 (10%)
6: 51 (11%)
7: 63 (14%)
8: 75 (16%)


Compare to this that I posted yesterday:
# of days per phase Jans 2011-25 (465 total days)/% of Jan days per phase

1: 17 (only 4%)
2: 26 (only 6%)
3: 67 (14%)
4: 51 (11%)
5: 57 (12%)
6: 101 (a whopping 22%)
7: 104 (a whopping 22%)
8: 42 (9%)


So, what changed the most in Jan when comparing 1975-89 to 2011-25?

# of 8-1-2 Jan days dropped sharply
# of 6-7 Jan days rose sharply

Jan 1975-89
8-1-2: 39%
6-7: 25%

Jan 2011-25
8-1-2: 18%
6-7: 44%

So for Jans when comparing 2011-25 to 1975-89, the # of 8-1-2 days dropped way down from 181 to only 85 (drop of 96 days) while the # of 6-7 days rose sharply from 114 to 205 (rise of 91 days)! Phase 8 went from having the largest # of days of any phase Jan 1975-89 to having only 40% of the largest # of days of any phase Jan 2011-25!

 
A quite possible explanation is the PDO cycle in conjunction with the strong W Pac warm pool. So, if the mean PDO would go positive, maybe Jan MJO dist. will revert back to 1975-89. Then again, the strong warm pool may be mainly due to CC?? If so, would it be easily reversible with a PDO change? A lot of this would seemingly be hard to answer.

—————
*Edit: Check this out

Avg PDO 

Jan 1975-89: avg +5.25/15 = +0.35

# of Jans: 8+, 3 neutral, 4-

 

Jan 2011-25: avg -11.59/15 = -0.77

# of Jans: 3+, 1 neutral, 11-

 

So, avg Jan PDO dropped sharply from +0.35 in 1975-89 to -0.77 in 2011-25.

@donsutherland1@bluewave@40/70 Benchmark@snowman19

[40/70 Benchmark]

1 hour ago, snowman19 said:

@40/70 Benchmark I’m assuming you disagree with Eric’s take that there’s going to be a big SPV strengthening then coupling with the troposphere leading to +AO/+NAO late winter into spring?
 

 

 

 

 

Yes. But it's probably a binary outcome...meaning one or the other.

[40/70 Benchmark]

1 hour ago, snowman19 said:

The 16-17 Niña matched this one pretty close….weak Niña, very strong -IOD that peaked in the fall, then a rapid, total Niña collapse in January, 2017 with a massive WWB and a record SOI crash (remains to be seen if this one has the big SOI crash and record WWB comparable to that January)…. @GaWx @PhiEaglesfan712

Except in terms of the EMI.

[donsutherland1]

59 minutes ago, GaWx said:

 I’m not disputing Eric, but it seems somewhat counterintuitive that the cold E US is still favored in Feb even with a +AO/+NAO. Wx history is so fascinating!

Cold is not favored in the East during February AO+/NAO+ dates. Nearly two thirds are warmer than normal. 

[40/70 Benchmark]

1 minute ago, donsutherland1 said:

Cold is not favored in the East during February AO+/NAO+ dates. Nearly two thirds are warmer than normal. 

Depends on the pattern, though...I'd give 2014 and 2015 another go-

[donsutherland1]

1 hour ago, 40/70 Benchmark said:

Depends on the pattern, though...I'd give 2014 and 2015 another go-

Of course. WPO-/EPO- can force cold outcomes even with a positive AO and NAO.  But if one is referring only to the general AO/NAO state, positive states are typically warmer, not colder regardless of ENSO. Other variables weren’t noted. 

[PhiEaglesfan712]

3 hours ago, snowman19 said:

The 16-17 Niña matched this one pretty close….weak Niña, very strong -IOD that peaked in the fall, then a rapid, total Niña collapse in January, 2017 with a massive WWB and a record SOI crash (remains to be seen if this one has the big SOI crash and record WWB comparable to that January)…. @GaWx @PhiEaglesfan712

16-17 and 22-23 were my favored analogs at the beginning of the season. I always felt that December was going to be on the cooler side (this verified), but January and February were going to be warmer (looks like that's what's happening).

[As I'm typing this, I'm using my fan for the first time since November. It's getting warm already!]

[40/70 Benchmark]

25 minutes ago, PhiEaglesfan712 said:

16-17 and 22-23 were my favored analogs at the beginning of the season. I always felt that December was going to be on the cooler side (this verified), but January and February were going to be warmer (looks like that's what's happening).

[As I'm typing this, I'm using my fan for the first time since November. It's getting warm already!]

What are you smoking?

[snowman19]

[michsnowfreak]

4 hours ago, so_whats_happening said:

Yea it is a fascinating climo around here. 

Yea I was on shift when we got that .2" lol did not expect the season to be just horrid. Unfortunately Baltimore may have some snow total issues for storms in the future. We are no longer measuring as weather observers it is across the airfield now, measured by EMS.

I think most airports are going the way of that. DTW has had paid snow observers for like 15+ years. A lot of other places do too (paid observers, volunteer, etc). I think the goal is to find a good/feasible spot to measure away from the airfield (harder to measure, plus faa dont want it anyway). As long as its within a 5 mile radius or less of the airport, its good.

[PhiEaglesfan712]

1 hour ago, 40/70 Benchmark said:

What are you smoking?

The temperature departure for January is going to be near normal by the end of today, if not tomorrow, in many places in the East, with the warmup just starting. I don't see sustained cold anywhere in the near future. We may not end up the absurd positive temperatures of January 2017 or 2023, but January should end with above average temperature departures in most places in the East.

[40/70 Benchmark]

7 minutes ago, PhiEaglesfan712 said:

The temperature departure for January is going to be near normal by the end of today, if not tomorrow, in many places in the East, with the warmup just starting. I don't see sustained cold anywhere in the near future. We may not end up the absurd positive temperatures of January 2017 or 2023, but January should end with above average temperature departures in most places in the East.

Agree with above, but def very modest departures. 

[PhiEaglesfan712]

MEI just updated. ND 2025 came in at -0.8

[snowman19]

1 hour ago, PhiEaglesfan712 said:

MEI just updated. ND 2025 came in at -0.8

That MEI number is proof of a very well coupled (ocean-atmosphere) La Niña 

[michsnowfreak]

2 hours ago, PhiEaglesfan712 said:

The temperature departure for January is going to be near normal by the end of today, if not tomorrow, in many places in the East, with the warmup just starting. I don't see sustained cold anywhere in the near future. We may not end up the absurd positive temperatures of January 2017 or 2023, but January should end with above average temperature departures in most places in the East.

I have to disagree. Extended looks cold after midmonth

[so_whats_happening]

3 hours ago, michsnowfreak said:

I think most airports are going the way of that. DTW has had paid snow observers for like 15+ years. A lot of other places do too (paid observers, volunteer, etc). I think the goal is to find a good/feasible spot to measure away from the airfield (harder to measure, plus faa dont want it anyway). As long as its within a 5 mile radius or less of the airport, its good.

The issue isnt we should be doing the measuring. The issue is a reliable source for measuring there have already been 2 incidents of bad measurements in the few events we have had. When the the surrounding area is about 2.5-3" and there is clearly 2.5-3" on the ground but only 1" is reported it starts to skew climo data not in a good way.

When we get paid to do virtually everything climo wise for the airport but snow is a no go it really doesn't make much sense. We still calculate the snow to liquid it doesn't take away from our duties considering for many many years it was never an issue.

1 hour ago, snowman19 said:

That MEI number is proof of a very well coupled (ocean-atmosphere) La Niña 

The numbers dropped from -1.1 (-1.2 at peak) to now -.8 becoming less coupled everyday.

[40/70 Benchmark]

@GaWxLarry,  it has that El Niño look because of the Pacific airmass....that is what I tried to capture in my January composite....pretty similar look with months like January 2006 and 2002 in there.

[raindancewx]

The subsurface rapidly warming in the cold season tends to correspond to colder periods out here. We should have an actual, real, cold day locally tommorow - in line with that idea, and the observed rapid warming.

High of 38F/low of 19F forecast for tommorow. Already seeing rain transition over to snow. It's actually kind of neat that we're still getting snow in this pattern since we're literally running >10F above average winter to date (Dec 1-).

Month to date, as in December, the greatest warmth relative to averages is found in the Northwest (+15-20F so far). We're already just about at/over average precipitation locally for January as of 1/8. We're already above Nov-Jan mean precipitation too. I've seen people liken the winter to 2017-18, and the warmth concentrating in the West so far is a bit like that. But precip is very different - we went 96 days without any measurable precip here from Oct-Jan in that winter, and went from Oct-Feb without 0.1" total at one point. This is a much warmer, but much wetter (better) pattern for the West. I still expect January to see the beginning of a cold retrograde to the West, but everything has been running a week later than I expected. The relatively widespread eastern/plains cold I thought would come in wk1 January is showing up for week 2/3 in the CPC 8-14 outlook (with 2022-23 showing as an analog each run). That cold should settle in for a bit and then retrograde West in late January and especially February.

Locally the MJO/harmonic storm cycle seems to be ~48 days this cold-season, ~early Oct/late Nov/early Jan so far. So I'd expect more decent  rain/snow events here in late Feb/early Apr before the pattern breaks.

 

[so_whats_happening]

What an interesting pattern the 00z GFS showed up to 240hrs @ 10mb

The 500mb maps were also very interesting, of course one run but don't think I have seen tropo/strato connection in this way with multiple 500mb lobes developing especially one still sitting in the Beaufort Sea/ CAA before.

This would probably be considered a minor wave 2 event but not a whole lot of warming taking place which is something that is lacking in completely taking down the SPV.

[40/70 Benchmark]

5 hours ago, so_whats_happening said:

What an interesting pattern the 00z GFS showed up to 240hrs @ 10mb

The 500mb maps were also very interesting, of course one run but don't think I have seen tropo/strato connection in this way with multiple 500mb lobes developing especially one still sitting in the Beaufort Sea/ CAA before.

This would probably be considered a minor wave 2 event but not a whole lot of warming taking place which is something that is lacking in completely taking down the SPV.

The theme for latter January will be stretching....the knock out punch comes in February.

[donsutherland1]

Social media noise about pattern chaos and dramatic shifts in social media videos notwithstanding, I am impressed how drama-free and orderly the pattern progression has been so far this month. 

The East was supposed to experience a thaw of about a week or so. That's playing out nicely. Afterward, a gradual transition toward colder but not severely cold weather was expected to occur. That's poised to play out. Most of the southern tier with the exception of the Southwest where a well-signaled intrusion of cold is now underway, was expected to stay mild. It has. 

Going forward, the progression toward cold from the Great Lakes to the Northeast (Mid-Atlantic and New England) remains on course. No significant Arctic outbreaks or snowstorms are likely through mid-month. Afterward, there is potential for the cold pattern to become snowy, but that's where the largest uncertainty rests. If the PNA undergoes a regime change to predominantly positive values near or after mid-month, prospects for East Coast snowstorms would increase. If not, frequent, but smaller snowfalls would be the norm. An WPO-/EPO-/AO- pattern is generally cold regardless of the PNA except in the Southeast (PNA+ is cold). By the end of this weekend, one should have higher confidence in the PNA evolution. Historically, a regime change is favored following the break in long-duration winter PNA- periods. But one cannot rule out a more unusual situation where the PNA only briefly goes positive before returning to its mainly negative state. However, extended range PNA forecasts which have low skill are insufficient. 

Overall, January still appears on course for a colder than normal outcome from the Great Lakes to New England. The southern tier from the desert southwest across to the Southeast will likely wind up with warm anomalies. Cold shots will still be possible, particularly in the Southeast as the month advances.

Finally, with respect to the La Niña, the atmosphere remains well-coupled. The AAM- is powerful proof that things remain coupled. Nevertheless, the La Niña continues to fade, and that process will continue through the winter. Weekly figures could begin to reach values just below La Niña threshold during late January. A significant WWB is possible this month. If it occurs, it would be unusual but not unprecedented. One such WWB occurred during Winter 2016-17. That a WWB might occur won't necessarily mean that February has to be cold. February 2017 wound up being exceptionally warm. I do not expect that scenario this time around. The full range of variables easing influence of ENSO, teleconnections, etc., will determine the February 2026 outcome.

 

[40/70 Benchmark]

7 minutes ago, donsutherland1 said:

Social media noise about pattern chaos and dramatic shifts in social media videos notwithstanding, I am impressed how drama-free and orderly the pattern progression has been so far this month. 

The East was supposed to experience a thaw of about a week or so. That's playing out nicely. Afterward, a gradual transition toward colder but not severely cold weather was expected to occur. That's poised to play out. Most of the southern tier with the exception of the Southwest where a well-signaled intrusion of cold is now underway, was expected to stay mild. It has. 

Going forward, the progression toward cold from the Great Lakes to the Northeast (Mid-Atlantic and New England) remains on course. No significant Arctic outbreaks or snowstorms are likely through mid-month. Afterward, there is potential for the cold pattern to become snowy, but that's where the largest uncertainty rests. If the PNA undergoes a regime change to predominantly positive values near or after mid-month, prospects for East Coast snowstorms would increase. If not, frequent, but smaller snowfalls would be the norm. An WPO-/EPO-/AO- pattern is generally cold regardless of the PNA except in the Southeast (PNA+ is cold). By the end of this weekend, one should have higher confidence in the PNA evolution. Historically, a regime change is favored following the break in long-duration winter PNA- periods. But one cannot rule out a more unusual situation where the PNA only briefly goes positive before returning to its mainly negative state. However, extended range PNA forecasts which have low skill are insufficient. 

Overall, January still appears on course for a colder than normal outcome from the Great Lakes to New England. The southern tier from the desert southwest across to the Southeast will likely wind up with warm anomalies. Cold shots will still be possible, particularly in the Southeast as the month advances.

Finally, with respect to the La Niña, the atmosphere remains well-coupled. The AAM- is powerful proof that things remain coupled. Nevertheless, the La Niña continues to fade, and that process will continue through the winter. Weekly figures could begin to reach values just below La Niña threshold during late January. A significant WWB is possible this month. If it occurs, it would be unusual but not unprecedented. One such WWB occurred during Winter 2016-17. That a WWB might occur won't necessarily mean that February has to be cold. February 2017 wound up being exceptionally warm. I do not expect that scenario this time around. The full range of variables easing influence of ENSO, teleconnections, etc., will determine the February 2026 outcome.

 

Absolutely....many on social media, including DT, are always inclined to rush the demise of ENSO. It's tiresome.

I do expect the PNA to be the primary catalyst for some significant snowfall here in short order, as I do not expect NE coastal snowfall to remain this paltry.

[so_whats_happening]

1 hour ago, 40/70 Benchmark said:

The theme for latter January will be stretching....the knock out punch comes in February.

We shall see coming up here overall it may not be needed but it would have been a nice feature to have to get a more sustained pattern to set up.

[so_whats_happening]

On 12/19/2025 at 1:22 AM, so_whats_happening said:

Ill ask my work colleague as I am also interested if there is something out there. I don't see why there wouldn't be. I start vacation this weekend into the new year so I'll have free time to finally catch up on things online (thankfully). I know I keep saying this but I will set up the thread this weekend to chat about RONI.

Im still surprised so many folks are caught off guard by this warm up and the potential of it being an extensive one at that, I wouldn't go as far as to say we are 'torching' but some areas especially in the southern plains and even lower midwest could hit record territory. Been beating this warm drum since about the beginning of the month.

Even with the prospects of a deep -NAO coming up this does not cause any bit of a cooldown for much of the east after christmas into the new year, as should be expected. I would not be surprised to see temps get to average if not slightly below average a few times during the week before the end of the year but overall much of the cold that has been across the eastern 1/3rd of the country should take a solid beating on the monthly scale. The cold is locked in Alaska and NW Canada I do expect as we get into the new year and especially after the first week for us to push a more normal state temp wise and eventually that cold should dislodge and make a run into the CONUS. 

We should know the models have a hard time grasping these types of pattern evolving (the potential retrogression) just like they tend to rush a -NAO out much quicker than reality suggests.

 

1 hour ago, donsutherland1 said:

Social media noise about pattern chaos and dramatic shifts in social media videos notwithstanding, I am impressed how drama-free and orderly the pattern progression has been so far this month. 

The East was supposed to experience a thaw of about a week or so. That's playing out nicely. Afterward, a gradual transition toward colder but not severely cold weather was expected to occur. That's poised to play out. Most of the southern tier with the exception of the Southwest where a well-signaled intrusion of cold is now underway, was expected to stay mild. It has. 

Going forward, the progression toward cold from the Great Lakes to the Northeast (Mid-Atlantic and New England) remains on course. No significant Arctic outbreaks or snowstorms are likely through mid-month. Afterward, there is potential for the cold pattern to become snowy, but that's where the largest uncertainty rests. If the PNA undergoes a regime change to predominantly positive values near or after mid-month, prospects for East Coast snowstorms would increase. If not, frequent, but smaller snowfalls would be the norm. An WPO-/EPO-/AO- pattern is generally cold regardless of the PNA except in the Southeast (PNA+ is cold). By the end of this weekend, one should have higher confidence in the PNA evolution. Historically, a regime change is favored following the break in long-duration winter PNA- periods. But one cannot rule out a more unusual situation where the PNA only briefly goes positive before returning to its mainly negative state. However, extended range PNA forecasts which have low skill are insufficient. 

Overall, January still appears on course for a colder than normal outcome from the Great Lakes to New England. The southern tier from the desert southwest across to the Southeast will likely wind up with warm anomalies. Cold shots will still be possible, particularly in the Southeast as the month advances.

Finally, with respect to the La Niña, the atmosphere remains well-coupled. The AAM- is powerful proof that things remain coupled. Nevertheless, the La Niña continues to fade, and that process will continue through the winter. Weekly figures could begin to reach values just below La Niña threshold during late January. A significant WWB is possible this month. If it occurs, it would be unusual but not unprecedented. One such WWB occurred during Winter 2016-17. That a WWB might occur won't necessarily mean that February has to be cold. February 2017 wound up being exceptionally warm. I do not expect that scenario this time around. The full range of variables easing influence of ENSO, teleconnections, etc., will determine the February 2026 outcome.

 

Seems as though I was off a bit on overall progression of near normal for the region. Warmth extended a little bit longer than previously expected. As for the AAM maybe it is because it is standardized that it is different from the CFS forecast of showing around -1.

[michsnowfreak]

1 hour ago, 40/70 Benchmark said:

The theme for latter January will be stretching....the knock out punch comes in February.

I know youve mentioned you like March...but what do you mean for February re: the knockout punch? Traditionally the east IS warmer but not all out torch like some imply. I really like the look for here. A lot of Nina Februarys have a really nice snowy pattern (but also some mild days). Plus Feb has killed it the last few decades.