2024-2025 La Nina

[so_whats_happening]

Little battle between the GFS and Euro/JMA as to the handling of the MJO progression coming up. GFS wants to swing this through 5-6-7 while Euro and JMA stop in 5 and move over toward null and eventually 8-1 (weak through 6-7) by the end of the month. This will be pretty important for potential Tropical activity going forward. 

They seem to be hitting the idea of a 5 pattern pretty well going into the last week or so of July with maybe a touch of 6 briefly. I used La Nada because we are largely still at this even with a decent subsurface look.

This should help us a bit with a more stormy pattern into the ohio valley mid atlantic regions coming up. Of course depending on the upcoming weeks form will determine what happens as we go into August but would suspect if the Euro was right we see very little 7 influence and some 8-1 into August with probably still largely La Nada conditions.

There doesn't seem to be a whole lot of data for an 8 passage in Nada conditions but if a phase 1 is any indication we see a weakness in the East and high latitude blocking occur.

[Stormchaserchuck1]

Jan-March 2014 is another example of the ENSO subsurface dictating the pattern. 

We had a Kelvin wave, or "Weak El Nino" in the subsurface, while the surface was Neutral, to neg Neutral. 

Gave us that +PNA/-EPO

And the net effect of an El-Nino subsurface, or strong Kelvin wave is cold anomalies across the eastern 2/3 of CONUS. (it actually seems to be a stronger indicator when you do relative value of subsurface minus surface)

On easternuswx, I made an index about this, going back to 1979, and found it correlated up to +40% vs Nino 3.4. 

Now it's harder to make custom timeseries, there are error messages on the CDC site (problems with ftp). If someone knows how to do it, let me know, and if I have time, I'll run a subsurface total dataset again going back to 1979. 

[Stormchaserchuck1]

5 hours ago, brooklynwx99 said:

with that being said, this winter does look to begin east-based, which may make December pretty interesting. I'll start digging into some more concrete analogs over the coming month or so

I'm starting to think the event may play out as more of an east-based event unless the Hadley Cells over the PDO region stretch it west. Last years El Nino started east-based then moved into record Nino 4 SSTs by the Fall, but the total event acted very east-based through the Winter. There may be a lag in effect lately. Some of those brutal warm Winters like 98-99 and 99-00 started west-based, vs progressing that way. I'd have to do the research to see if there is something to that..

[bluewave]

13 hours ago, Stormchaserchuck1 said:

Actually, we had -PNA conditions during last years El Nino, so I could argue that it's been La Nina conditions for 8 years in a row.. although the STJ was strong last year, and global precipitable water spiked. 

This is just an amazing map, because it features 14 months, over a 7-year-consecutive period. Going back to 1948, we've never seen an anomaly greater.. #2 was +95dm over the -NAO region 1964-1969, and I think that was just for a 1-month period. 

The pattern starts right after the N. Hemisphere's coldest day of the year (Jan 27th), which I don't think is a coincidence. 

It's my personal opinion that the wave hit in 2013. I was personally observing the sun shining brighter and hotter way before the 2015+ period even came to be. So again, this is just personal conjecture but I think the 14-16 +PDO and El Nino was an opposite wave to what was happening. 

I would say sun spikes if I didn't know better, but we have definitely seen something a major change/pattern take place, after 2013 (you say Dec 2015.) It's especially seen in the Pacific. I think a secondary wave came in 2018-2019, and since then the -NAO has been correlation with -PNA and +EPO, and +PNA/+NAO and -EPO. It will be interesting to see if that eases up or changes in the next few years.. ENSO climatology/roll forward says we have a good shot at +PNA 2026-2028. 

This is the 1st time we have had such a strong and persistent Aleutian ridge over a 9 year period going back to the 1950s. Previous -PDO eras never had such a strong Aleutian ridge. So this is something new over the last 9 winters. The old -PDOs were more defined by their stronger -PNA troughs over Western North America. Since the -PDO from 1950s into 1970s didn’t have the strong Aleutian ridge, they also didn’t have a Southeast ridge. This is why the old -PDO winters were much colder in the East. We can remember cold -PNA patterns back then for the East. This new Aleutian ridge teleconnection has been an important driver of the Southeast ridge and record 9 warm winters in a row in parts of the East. Both ridges  are function of the marine heatwaves in the MJO 4-7 regions generating this winter standing wave pattern through the stronger MJO 4-7 forcing. Plus the marine heatwaves east of Japan are also linked into this process. This process has also been warming the NW Atlantic leading to even stronger ridges in the East. 

 

 

 

 

[GaWx]

1 hour ago, bluewave said:

This is the 1st time we have had such a strong and persistent Aleutian ridge over a 9 year period going back to the 1950s. Previous -PDO eras never had such a strong Aleutian ridge. So this is something new over the last 9 winters. The old -PDOs were more defined by their stronger -PNA troughs over Western North America. Since the -PDO from 1950s into 1970s didn’t have the strong Aleutian ridge, they also didn’t have a Southeast ridge. This is why the old -PDO winters were much colder in the East. We can remember cold -PNA patterns back then for the East. This new Aleutian ridge teleconnection has been an important driver of the Southeast ridge and record 9 warm winters in a row in parts of the East. Both ridges  are function of the marine heatwaves in the MJO 4-7 regions generating this winter standing wave pattern through the stronger MJO 4-7 forcing. Plus the marine heatwaves east of Japan are also linked into this process. This process has also been warming the NW Atlantic leading to even stronger ridges in the East. 

 

 

 

 

Chris,

 Are you able to change the climo periods from 1991-2020 for the bottom 5?

[bluewave]

29 minutes ago, GaWx said:

Chris,

 Are you able to change the climo periods from 1991-2020 for the bottom 5?

Since the 500 mb heights continue to rise as we warm, they get updated to the most recent 30 year normals which are the highest. If we could go back to a 1961-1990 period, then the current 500 mb height anomalies south of the Aleutians would look even more impressive with that older climo. They allow you to adjust the temperatures for the older climate normals. So the current winter temperatures look much more impressive since 15-16 using the colder 1961-1990 normals.

 

 

 

[snowman19]

3 hours ago, bluewave said:

This is the 1st time we have had such a strong and persistent Aleutian ridge over a 9 year period going back to the 1950s. Previous -PDO eras never had such a strong Aleutian ridge. So this is something new over the last 9 winters. The old -PDOs were more defined by their stronger -PNA troughs over Western North America. Since the -PDO from 1950s into 1970s didn’t have the strong Aleutian ridge, they also didn’t have a Southeast ridge. This is why the old -PDO winters were much colder in the East. We can remember cold -PNA patterns back then for the East. This new Aleutian ridge teleconnection has been an important driver of the Southeast ridge and record 9 warm winters in a row in parts of the East. Both ridges  are function of the marine heatwaves in the MJO 4-7 regions generating this winter standing wave pattern through the stronger MJO 4-7 forcing. Plus the marine heatwaves east of Japan are also linked into this process. This process has also been warming the NW Atlantic leading to even stronger ridges in the East. 

 

 

 

 

This is why winter forecasts keep busting year after year, over and over. Certain folks never, ever learn. We are not seeing the same climate we did back in the 50’s-early 2000’s. Even the 2010’s. Yet every year, we see people using old analogs, expecting the current winter to do the same thing, then being shocked when they completely fail. I’ve said this before and I’ll say it again, we need to see full scale, major changes in the PAC, Atlantic and background forcing. Until then it’s more of the same, minus a very lucky temporary, transient month of favorable (i.e. February, 2021). Nothing at all has changed as you just showed and until it does, it’s wash, rinse, repeat. An example right now on twitter is how we are seeing people hyping that this La Niña is developing just like 2017, which was a classic east-based event, started as one, ended as one. All you have to do is compare how this Niña is developing with 2017. It’s not even close. Wishcasting it won’t make it happen, which is my issue. It’s the same cast of characters using the same cold and snowy analogs (95-96, 10-11, 13-14, 17-18) everytime there’s a La Niña, and saying that this year is a carbon copy, just like they do with the analogs everytime there’s an El Niño (57-58, 65-66, 76-77, 77-78, 02-03, 09-10). You can’t will it to happen. I’m sure the same people undoubtedly will go cold and snowy this year too, as they always do. Adjust and adapt. Madness is doing the same thing over and over and expecting a different result…..

[GaWx]

 The last 3 days’ SOIs have been sub -25. Despite them now bottoming out and about to rise back up, the July complete month might end up slightly negative.

 What’s been driving the recent strong -SOI days have been very high Darwin SLPs. For those who don’t follow the SOI closely, a developing La Niña favors +SOIs in late spring and especially summer+. AN Tahiti SLP and BN Darwin SLP correlates to +SOI.

 But recent Darwin SLPs have been anything but low. On the contrary, we just had 2 days of 1017.55+ with today in highly rarified territory at 1017.85. How rare is 1017.85?

 Since 1991 and prior to today, there had been only 4 days with Darwin SLP of 1017.85+:

1018.35: June 22, 2004
1017.90: July 25, 2023
1017.90: Aug 5, 2023
1017.85: Aug 12, 1994

 Note that all of these other 4 1017.85+ Darwin days were during an incoming or already existent 1st year El Niño. That’s far from the case now.

Since 1991 there’s been only one day during a year with a first year Niña immediately following a Nino that had a Darwin SLP >1017 mb: the 1017.15 mb of Aug 12, 1995.

For Niña following Nino, highest daily Darwin SLP:

1995: 1017.15
1998: 1015.35
2005: 1016.00
2007: 1016.00
2010: 1014.65
2016: 1015.25

[George001]

17 hours ago, brooklynwx99 said:

I'm not expecting much for the E US this year... the strong -PDO and general progression to a more central-based event are certainly mitigating factors. would be surprised if there was AN snow for NYC, certainly DC. Boston could actually have a decent year as they do in Ninas

with that being said, this winter does look to begin east-based, which may make December pretty interesting. I'll start digging into some more concrete analogs over the coming month or so

Yep, the more north storm track in Nina’s can be good for SNE if the SE ridge doesn’t flex too much and torch the entire east. 

[brooklynwx99]

14 minutes ago, George001 said:

Yep, the more north storm track in Nina’s can be good for SNE if the SE ridge doesn’t flex too much and torch the entire east. 

even in 2022-23, NNE (and even parts of CNE) had a pretty torrid February if I remember correctly

[qg_omega]

Looks like another record warm and snowless winter incoming.  

[michsnowfreak]

On 7/16/2024 at 8:00 PM, so_whats_happening said:

Yea the biggest change by far has been overnight temps in all seasons. The biggest changes of course have been in winter but in summer we are feeling it a bit over this way. Average night temp is around 68 here at BWI we have steadily been around 72-75 with spikes of around 76-80 with this heat of recent. In the last month alone we have gone below 67-68 area about 4 times all the while being in a D1 drought. Hopefully it breaks for a bit coming up here the house is way too hot with no central air.

Interesting...warmer mins are more noticeable in summer than winter here. We still routinely go below zero most winters. Yet in summer, we almost never see 40s in July or August whereas we used to see the occasional night or two (the outlying areas still do..in fact they did last night lol).

[michsnowfreak]

5 hours ago, snowman19 said:

This is why winter forecasts keep busting year after year, over and over. Certain folks never, ever learn. We are not seeing the same climate we did back in the 50’s-early 2000’s. Even the 2010’s. Yet every year, we see people using old analogs, expecting the current winter to do the same thing, then being shocked when they completely fail. I’ve said this before and I’ll say it again, we need to see full scale, major changes in the PAC, Atlantic and background forcing. Until then it’s more of the same, minus a very lucky temporary, transient month of favorable (i.e. February, 2021). Nothing at all has changed as you just showed and until it does, it’s wash, rinse, repeat. An example right now on twitter is how we are seeing people hyping that this La Niña is developing just like 2017, which was a classic east-based event, started as one, ended as one. All you have to do is compare how this Niña is developing with 2017. It’s not even close. Wishcasting it won’t make it happen, which is my issue. It’s the same cast of characters using the same cold and snowy analogs (95-96, 10-11, 13-14, 17-18) everytime there’s a La Niña, and saying that this year is a carbon copy, just like they do with the analogs everytime there’s an El Niño (57-58, 65-66, 76-77, 77-78, 02-03, 09-10). You can’t will it to happen. I’m sure the same people undoubtedly will go cold and snowy this year too, as they always do. Adjust and adapt. Madness is doing the same thing over and over and expecting a different result…..

Winter forecasts have always busted...and this includes when the harsher winters were forecast to be mild. Its because forecasts are plentiful, and many have biases one way or the other.

Its laughable to lump the 1950s-2000s climate into one  Winters of the 1950s and 1990s were very mild in many places while the 1960s and particularly 1970s were the coldest and harshest of all time in spots. Winters for me were much more harsh in the 2000s/2010s than growing up in the 1990s, and id able to use that same sentiment in the 1970s if i grew up in the 1950s. 

[michsnowfreak]

On 7/18/2024 at 10:24 AM, bluewave said:

Yeah, that Arctic outbreak at the end of January 2019 was very impressive in the Midwest. While the warmth has dominated US winters since 15-16, there have been a few potent Arctic outbreaks. Another was in Texas during the 20-21 winter. The common theme is that the core of several of them have remained west of the Northeast closer to the center of the Continent. 
 

 

Dec 2017, Jan 2019, Feb 2021, Dec 2022, Jan 2024 were all impressive arctic outbreaks despite the domination of mild winters since 2016. 

[michsnowfreak]

On 7/18/2024 at 11:33 AM, 40/70 Benchmark said:

What is interesting is that we are still able to generate severe cold, but rather it is the residence time that is mitigated by CC. Intuiitively speaking it is the former that is more important for major winter storm (blizzard) genesis. We just need the right pattern.

Excellent point. If I just categorized winters by min temp rather than mean temp, not only would you see no rise (the period of record regress line is straight as an arrow 1874-present), you would see the average annual winter min temp has gotten colder if you narrow the data set to the past 100 years (at Detroit). Id suspect its even more pronounced in areas west of Lake MI. 

[PhiEaglesfan712]

2007-08 is a really good analog at this point. Just look at the subsurface. 

[mitchnick]

14 minutes ago, PhiEaglesfan712 said:

2007-08 is a really good analog at this point. Just look at the subsurface. 

Surface is more than a little bit different however. If Chuck's right, it won't matter much. In any event, considering Gawx's post on the SOI and persistent warmth in Enso 3.4 & 4, it's "likely" going to take a real turnaround to get an ONI colder than a weak Niña imho. But that could change, of course.

[PhiEaglesfan712]

By the way, here's the mid-July IRI plot: 

[40/70 Benchmark]

1 hour ago, PhiEaglesfan712 said:

2007-08 is a really good analog at this point. Just look at the subsurface. 

I have been saying that...QBO is off and solar is deep descending, but I like it....

[Stormchaserchuck1]

CPC has been way more aggressive on La Nina call, and they are doing really good right now with monthly and seasonal forecasts, but Gawx is right, the surface is not really cooling and the SOI is deeply negative. 

https://www.longpaddock.qld.gov.au/soi/

[40/70 Benchmark]

5 hours ago, brooklynwx99 said:

even in 2022-23, NNE (and even parts of CNE) had a pretty torrid February if I remember correctly

January was okay IMBY.

[40/70 Benchmark]

8 hours ago, snowman19 said:

This is why winter forecasts keep busting year after year, over and over. Certain folks never, ever learn. We are not seeing the same climate we did back in the 50’s-early 2000’s. Even the 2010’s. Yet every year, we see people using old analogs, expecting the current winter to do the same thing, then being shocked when they completely fail. I’ve said this before and I’ll say it again, we need to see full scale, major changes in the PAC, Atlantic and background forcing. Until then it’s more of the same, minus a very lucky temporary, transient month of favorable (i.e. February, 2021). Nothing at all has changed as you just showed and until it does, it’s wash, rinse, repeat. An example right now on twitter is how we are seeing people hyping that this La Niña is developing just like 2017, which was a classic east-based event, started as one, ended as one. All you have to do is compare how this Niña is developing with 2017. It’s not even close. Wishcasting it won’t make it happen, which is my issue. It’s the same cast of characters using the same cold and snowy analogs (95-96, 10-11, 13-14, 17-18) everytime there’s a La Niña, and saying that this year is a carbon copy, just like they do with the analogs everytime there’s an El Niño (57-58, 65-66, 76-77, 77-78, 02-03, 09-10). You can’t will it to happen. I’m sure the same people undoubtedly will go cold and snowy this year too, as they always do. Adjust and adapt. Madness is doing the same thing over and over and expecting a different result…..

Past analogs still have utility, but you need to know how to use them and and thr adjustments to make.

[snowman19]

11 hours ago, Stormchaserchuck1 said:

CPC has been way more aggressive on La Nina call, and they are doing really good right now with monthly and seasonal forecasts, but Gawx is right, the surface is not really cooling and the SOI is deeply negative. 

https://www.longpaddock.qld.gov.au/soi/

I think we can put the La Nada/neutral fantasies away. There’s going to be a La Niña, the only question now is how strong?

[snowman19]

13 hours ago, PhiEaglesfan712 said:

2007-08 is a really good analog at this point. Just look at the subsurface. 

Nice comparison. It actually is developing very similar to 2007. Real close. Which was NOT an east-based La Niña. It also looks nothing at all like 2017. Not sure where these twitter proclamations are coming from that this one is developing as an east-based event

[bluewave]

1 hour ago, snowman19 said:

Nice comparison. It actually is developing very similar to 2007. Real close. Which was NOT an east-based La Niña. It also looks nothing at all like 2017. Not sure where these twitter proclamations are coming from that this one is developing like an east-based event

Just in terms of ONI, this reminds me of the transition from our last strong to super El Niño in 16-17. There was so much SST warmth leftover from that event in 2016, that the La Niña only achieved weak ONI for the 16-17 La Niña winter. It was a very warm winter since there was so much global heat left over from the previous winter being a super El Niño. The stronger La Niña didn’t arrive until 17-18. 
 

2016	2.5	2.1	1.6	0.9	0.4	-0.1	-0.4	-0.5	-0.6	-0.7	-0.7	-0.6
2017	-0.3	-0.2	0.1	0.2	0.3	0.3

Super El Niño 

 

To weak La Nina

 

Weak La Niña surrounded by residual super El Niño warmth

[mitchnick]

9 hours ago, snowman19 said:

I think we can put the La Nada/neutral fantasies away. There’s going to be a La Niña, the only question now is how strong?

Along with the moderate/strong to strong.

[snowman19]

3 minutes ago, mitchnick said:

Along with the moderate/strong to strong.

16-17 and 07-08 are starting to look good matches for this Niña 

[mitchnick]

7 minutes ago, snowman19 said:

16-17 and 07-08 are starting to look good matches for this Niña 

I have no idea how it ultimately turns out ONI-wise. Anything from a La Nada to barely moderate is still on the table imho, with weak Niña favored. Regardless of ONI, however, we're definitely stuck in a Niña background state which also leaves a wide variety of possibilities for the winter. If one is planning on issuing a winter forecast, I'd put off the issue date as long as possible. Lol

[TheClimateChanger]

17 hours ago, michsnowfreak said:

Interesting...warmer mins are more noticeable in summer than winter here. We still routinely go below zero most winters. Yet in summer, we almost never see 40s in July or August whereas we used to see the occasional night or two (the outlying areas still do..in fact they did last night lol).

The threaded record does show a positive regression, from a predicted value of 19.6F in 1875 to a predicted value of 21.3F in 2024. The LOESS curve helps to highlight the fact that the vast majority of recent winters have seen mean minima well above the values predicted by a linear regression, suggesting the linear regression is not fully capturing the trend and there has been an acceleration in the increase in winter minima since around 2000.

In fact, the trend is greatly affected by changes in site location and instrument exposure, suggesting mean winter minima have warmed faster than shown here. This will be addressed in a follow-up post.

Detroit [ThreadEx]

Detroit City Airport [KDET]

Detroit Metropolitan Wayne Airport [KDTW]

[snowman19]

1 hour ago, mitchnick said:

I have no idea how it ultimately turns out ONI-wise. Anything from a La Nada to barely moderate is still on the table imho, with weak Niña favored. Regardless of ONI, however, we're definitely stuck in a Niña background state which also leaves a wide variety of possibilities for the winter. If one is planning on issuing a winter forecast, I'd put off the issue date as long as possible. Lol

I don’t think winter forecasts should be put out until November. That said, as of right now, just looking at ENSO, 16-17 and 07-08 seem to be good matches