2024-2025 La Nina

[michsnowfreak]

13 minutes ago, George001 said:

The thing is it’s been happening more often. It seems like every other year it hits 70 in Feb or Mar, I don’t remember that being normal even 10 years ago.

"I don't remember" is a dangerous word to use in weather haha . Looking up the actual data can really surprise you. Not an encyclopedia of weather knowledge for Boston as I am for Detroit...and I do know east coast winters have warmed a bit more than here (I've found that fall/winter warming is much slower than spring/summer here)....but when you actually look at data you might be surprised. Using just our memories is how the tales "when I was a kid" start. Since the beginning of climate record there have been eye popping warm months, out-of-season warm temps at any time of year, and multi-year cycles of unusually warm weather. They just happened less frequently back then (how much less depends on location). 

[George001]

4 hours ago, snowman19 said:

Your 17-18 winter forecast was one of the best I’ve ever seen. One thing is for sure, besides all the other factors we’ve mentioned, this La Niña is definitely not developing as an east-based event this time around like 2017 did. This current configuration is not even close to resembling an east-based event:

 

 

 

 

Current anomalies:

Nino 4: +0.7

Nino 3.4: +0.3

Nino 3: -0.1

nino 1.2: -0.2.

Looking at the subsurface, there is a lot of cold near the surface in the ENSO 3 region. The developing subsurface cold pool is centralized in the ENSO 3.4 region. Am I missing something here? The subsurface + surface configuration appears at first glance to support future cooling in the ENSO 3.4, 3 and 1.2 regions with less cooling in the ENSO 4 region. That said, I do agree that when it actually maters (in the winter), the Nina will be less east based that 2017-2018 was. Regardless, it appears that the debate is between an east based and a basin wide event, there isn’t any signs of this turning into a modoki anytime soon.

[George001]

I actually think 2017-2018 is a good ENSO analog. It’s the other non ENSO related factors that make it not a great match.  Like Snowman mentioned earlier, 2017-2018 didn’t have a roasting Atlantic Ocean (raging +AMO), and the solar activity is significantly higher than it was that winter. There is a big jump between “2017-2018 is a good ENSO analog” to “we’re getting buried in March”. @40/70 Benchmarkhas been doing this more in his latest forecasts, using different analogs for different months, and separating the analog from the expected snow output, and taking climate change into account.

A good example is last year. 1957-1958 was listed as an analog, and it turned out to be an excellent match for the ENSO and raging STJ. However, the temp profile was completely different, and so were the snowfall outputs as a result. That doesn’t mean 1957-1958 was a shitty analog, if you looked at that and expected the same amount of snow as back then, thats just a fundamental misunderstanding of what analogs are supposed to do. Of course the temp profile was different, it’s a 60+ year old analog.

[so_whats_happening]

7 hours ago, snowman19 said:

Another crazy stat and it’s not even at the climatological lowest point of the year. My guess is this is related to the marine heat waves:
 

You should check out the Sea Ice thread good read in there, although it doesn't get much activity. We have surprisingly not set a record since 2012 we came rather close in 2020 though. Mush ice may create a different state and act differently on the surrounding environment than many had envisioned playing out. Certainly will keep watching as we go through the rest of this decade we maybe in that flatline area before the next step down. Coming up we may actually have a profound period of lower melt although having SLP around 980-985mb doesn't really help all too much.

[so_whats_happening]

1 hour ago, michsnowfreak said:

"I don't remember" is a dangerous word to use in weather haha . Looking up the actual data can really surprise you. Not an encyclopedia of weather knowledge for Boston as I am for Detroit...and I do know east coast winters have warmed a bit more than here (I've found that fall/winter warming is much slower than spring/summer here)....but when you actually look at data you might be surprised. Using just our memories is how the tales "when I was a kid" start. Since the beginning of climate record there have been eye popping warm months, out-of-season warm temps at any time of year, and multi-year cycles of unusually warm weather. They just happened less frequently back then (how much less depends on location). 

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.

[so_whats_happening]

Here is the latest subsurface from beginning of June to the current date. Also added Hovmoller forecasts for the next 2 weeks.

[so_whats_happening]

1 minute ago, so_whats_happening said:

Here is the latest subsurface from beginning of June to the current date. Also added Hovmoller forecasts for the next 2 weeks.

Here is 2007 and 2017 in comparison.

[raindancewx]

On 7/15/2024 at 10:41 AM, BlizzardWx said:

Here is what I have been working on for a sea surface temperature anomaly + (ssta based) index plot. It's possible some of the values are not correct yet and if you think so, let me know. But the idea will be that this is hosted and updates daily within a moth. I'll also do the atmospheric indices like I said. 

I'd like to see you change the color scheme by the North Pole. I doubt it is all below average? Otherwise this is a very useful product if you can update it easily. There are a lot of datasets for doing SST maps like this one. I would also add the baseline used. It looks like 1991-2020 to me but I can't prove it.

I would also add in the total (spatially weighted) SST warmth v. the baseline period as an index. Maybe the tropical warmth (23N-23S) too v. a baseline. I like the rectangular maps and automatically de-weight the lower/higher latitudes because the Earth is spherical. But a spherical representation would probably also do well.

[roardog]

7 hours ago, snowman19 said:

Another crazy stat and it’s not even at the climatological lowest point of the year. My guess is this is related to the marine heat waves:
 

This isn’t even all that bad in today’s world. If we ended the melt season at 8th lowest, we would be doing pretty good all things considered. 

[Stormchaserchuck1]

38 minutes ago, so_whats_happening said:

Here is 2007 and 2017 in comparison.

More organized negative subsurface this time.. especially compared to 2017. It's 200m below the central-west region, which is the most time lagged correlation. If I had to guess, that central-western part of the subsurface at the thermocline leads Nino 3/1.2 by as much as +45 days. 

[Stormchaserchuck1]

9 hours ago, snowman19 said:

Another crazy stat and it’s not even at the climatological lowest point of the year. My guess is this is related to the marine heat waves:

AO/NAO have been positive since ~June 18, it's probably about a +1.5 index for that time. We've actually seen pretty strong cold 500mb (over Greenland and NE Canada), for the first time in a while in the N. Hemisphere, this Summer. The ice melt is kind of surprising in that regard, and is happening in the same areas as before, north of Alaska and on the Pacific Ocean side.

The cold anomaly looks to continue over the Arctic circle for the next 15 days. 

[GaWx]

1 hour ago, so_whats_happening said:

Here is the latest subsurface from beginning of June to the current date. Also added Hovmoller forecasts for the next 2 weeks.

 The above animation clearly shows that the top ~100m is solidly holding as a warm layer.

[so_whats_happening]

28 minutes ago, GaWx said:

 The above animation clearly shows that the top ~100m is solidly holding as a warm layer.

Yea a 5N-5S approach shows we are still relatively weak even with the easterlies a blowin' right now. Should see some results before the end of the month, at least expansion westward of the cold neutral anomalies.

[40/70 Benchmark]

12 hours ago, George001 said:

I actually think 2017-2018 is a good ENSO analog. It’s the other non ENSO related factors that make it not a great match.  Like Snowman mentioned earlier, 2017-2018 didn’t have a roasting Atlantic Ocean (raging +AMO), and the solar activity is significantly higher than it was that winter. There is a big jump between “2017-2018 is a good ENSO analog” to “we’re getting buried in March”. @40/70 Benchmarkhas been doing this more in his latest forecasts, using different analogs for different months, and separating the analog from the expected snow output, and taking climate change into account.

A good example is last year. 1957-1958 was listed as an analog, and it turned out to be an excellent match for the ENSO and raging STJ. However, the temp profile was completely different, and so were the snowfall outputs as a result. That doesn’t mean 1957-1958 was a shitty analog, if you looked at that and expected the same amount of snow as back then, thats just a fundamental misunderstanding of what analogs are supposed to do. Of course the temp profile was different, it’s a 60+ year old analog.

Yea, it's an adjustment I have made to be more specific and highlight the intended utility of each respective analog....otherwise, you may like an element of a particular season and when you include it in the aggregate seasonal composite, you become involuntarily married to perceived snowfall implications. I think in addition to explicitly stating why you like a specific season, which no one reads, identifying which month you think will bare most resemblance to a given season helps to illustrate it more. For instance, if you think March will be decent, but the season will still suck..... you can include 2018 for March, yet drop seasons like 2002 and 2012 in January and February to guard against folks just focusing on 2018 and interpret that as the forecaster going for a huge season.

[PhiEaglesfan712]

10 hours ago, so_whats_happening said:

Here is 2007 and 2017 in comparison.

The top one turned into a strong la nina, while the bottom one stayed a weak la nina, and we can see why. From the animation, 2024 looks closer to 2007. I see a pocket of cool in both years (-3 and -4), while 2017 doesn't even have a -2.

[snowman19]

13 hours ago, roardog said:

This isn’t even all that bad in today’s world. If we ended the melt season at 8th lowest, we would be doing pretty good all things considered. 

It’s 8th now and we’re still over a month away from the climatological time of year when arctic sea ice normally bottoms out at its lowest. The question is how much lower does it go between now and then?

[snowman19]

3 hours ago, PhiEaglesfan712 said:

The top one turned into a strong la nina, while the bottom one stayed a weak la nina, and we can see why. From the animation, 2024 looks closer to 2007. I see a pocket of cool in both years (-3 and -4), while 2017 doesn't even have a -2.

We’ve discussed 17-18 ad nauseam, but this La Niña is not developing like that one did. The 17-18 Niña was a textbook east-based event, started as one and stayed as one. It wasn’t just east-based, it was very east-based. This one is not. Although, according to twitter weenieland this one is developing exactly like 2017. I understand why some folks want that, but there’s a fine line between what people want and reality…..

[roardog]

11 minutes ago, snowman19 said:

It’s 8th now and we’re still over a month away from the climatological time of year when arctic sea ice normally bottoms out at its lowest. The question is how much lower does it go between now and then?

I think it means 8th lowest for the date not 8th lowest overall since he was comparing it to the mean for each decade on that date. 

[snowman19]

20 minutes ago, roardog said:

I think it means 8th lowest for the date not 8th lowest overall since he was comparing it to the mean for each decade on that date. 

Either way, we are still well below average and have been for years. AGW, Marine heat waves, whatever may be the root cause, is bringing arctic sea ice to record low levels 

[FPizz]

1 hour ago, roardog said:

I think it means 8th lowest for the date not 8th lowest overall since he was comparing it to the mean for each decade on that date. 

It does mean that and is right on the line for the 2010s average.  Unless something drastic happens, we will be flirting with record lows every year.

[George001]

1 hour ago, snowman19 said:

We’ve discussed 17-18 ad nauseam, but this La Niña is not developing like that one did. The 17-18 Niña was a textbook east-based event, started as one and stayed as one. It wasn’t just east-based, it was very east-based. This one is not. Although, according to twitter weenieland this one is developing exactly like 2017. I understand why some folks want that, but there’s a fine line between what people want and reality…..

Do you think the models are drastically underestimating the strength of the Nina? They did in 2007-2008. I think they are a bit, but am still skeptical this becomes an high end event, though I am open to the possibility I am wrong about that. In my opinion, if the models bust on the strength they will be too weak, not too strong. I’m expecting a peak of around -0.9 to -1C, a bit stronger and more basin wide than 2017-2018 but still a good ENSO match. 

[snowman19]

6 minutes ago, George001 said:

Do you think the models are drastically underestimating the strength of the Nina? They did in 2007-2008.

Drastically? Probably not. However, I do think the Euro is way too warm and in a universe all to its own. As @GaWx posted the other day, all of the other new model runs got stronger with the La Niña. The Euro is the clear outlier

[GaWx]

11 minutes ago, snowman19 said:

Drastically? Probably not. However, I do think the Euro is way too warm and in a universe all to its own. As @GaWx posted the other day, all of the other new model runs got stronger with the La Niña. The Euro is the clear outlier

Repost:

Summary of latest SON ONI forecasts (subtract ~0.5 to estimate RONI):

Euro: warmed 0.2 to ~-0.1 (has a longterm warm bias/slightly too warm last year but warm bias stronger when non-Nino)

BoM: cooled 0.3 to ~-0.2 (huge warm bias last year)

MeteoFrance: cooled 0.5 to ~-0.4 (strong warm bias)

JMA: cooled 0.3 to ~-0.8 (no known significant bias/did well last year)

UKMET: cooled 0.1 to ~-1.0 (did best last year/no known significant bias)

CFS: warmed 0.1 to ~-1.1 (overall limited accuracy; I think it has cool bias)

 So, with the significantly cooler JMA/MeteoFrance, I’m thinking the chances for a solid weak La Niña per ONI are increasing again (vs cold neutral). This also means the chances for a moderate La Niña per RONI are increasing again (vs weak).

[roardog]

1 hour ago, FPizz said:

It does mean that and is right on the line for the 2010s average.  Unless something drastic happens, we will be flirting with record lows every year.

I guess that was kind of my point. Every year you get some dramatic news story or tweet about how low the sea ice is like it's never happened before when in reality it happens every summer now. Even if for some reason, the sea ice started to recover(I doubt it actually will)it would take decades to fully recover just like it took decades to decrease to where it is now. It would be a very slow process. I don't think it's even possible to have anything but near record low sea ice every summer with so much multi year ice gone. 

[Stormchaserchuck1]

A La Nina this year will make it 4/5 years that we have had La Nina conditions lately. Those similar cases were actually followed by some good Winters in the years after:

2007-2012, 4 La Nina's in 5 years. 

Winters 13-14 and 14-15 were cold. 

1995-2001, 4 La Nina's in 6 years. 

02-03 was cold, 03-04 and 04-05 were good snow years in the NE north of 40N. 

1970-1976, 5 La Nina's in 6 years. 

76-77, 77-78 and 78-79 were among the coldest Winter's on record. 

Combined First 3 Winters after 4/5-6 year La Nina's:

 

Years +2-3:

 

*No cases yet of 4/5-6 El Nino years. 

63-70 and 76-83 were 4/7 El Nino years. Following 3 Winter's:

+ and - put together [to default La Nina] shows the PNA usually reverses in the following 3 Winters:

 

Extra month: March, combined, years +2-3:

March all 3 years after 4/5-6 La Nina's total minus two 4-7 year El Nino's:

pretty good little signal there. I find it interesting that you have a tendency for the PNA to reverse, when the PDO is sort of a culmination index of conditions run forward, so consistency should be, if the PDO has correlation weight. But you see the opposite happen. 

Precip for the 3 La Nina bunches minus the 2 El Nino bunches (Combined First 3 years after):

[PhiEaglesfan712]

2 hours ago, Stormchaserchuck1 said:

*No cases yet of 4/5-6 El Nino years. 

63-70 and 76-83 were 4/7 El Nino years. Following 3 Winter's:

I wonder how much this map changes if we considered 51-52 through 58-59 a 5/8 el nino, and included the years 59-60, 60-61, and 61-62. Those were some cold and snowy winters here at PHL based on my spreadsheet.

[Stormchaserchuck1]

23 minutes ago, PhiEaglesfan712 said:

I wonder how much this map changes if we considered 51-52 through 58-59 a 5/8 el nino, and included the years 59-60, 60-61, and 61-62. Those were some cold and snowy winters here at PHL based on my spreadsheet.

The correlation should be opposite following El Nino's. 51-59 was 4/8 El Nino, and no years were borderline making it a close call for El Nino qualification.. Summer 1952 hit +0.2 ONI but that's the highest besides the linear up and down of ENSO. In there were 2 La Nina's too.. so 4 El Nino's and 2 La Nina's, and 2 Neutral's in 8 years.. I don't think that really matches 4/5 consecutive ENSO years. 

I thought you might find the research interesting though. It kind of goes with the El Nino tendency in +3-6 years that we were finding after a Strong El Nino (completely different variable, matching). It seems our sweet spot just per ENSO roll forwards is +3-4 Winters from now (26-28), with a slightly better chance next year vs this year. 

La Nina's are a cold water phase, and global cooling has been known to match it, just like global warming has been known to match El Nino's, so it actually makes a little bit of sense that a long term bunch of these years would precede some cooler conditions.  I always say be careful being down on La Nina's, because they are actually a cold climate phase. A La Nina this year might be associated with a PNA reverse afterward, who knows? 

[Stormchaserchuck1]

The Winter following a Super El Nino (peak ONI 2.0 or greater):

Actually makes some sense, because El Nino's are associated with global warming, that takes some time to offset, although that is a -PNA map so again, the reversal post-ENSO is a pretty strong signal. 

[snowman19]

On 7/16/2024 at 4:17 PM, GaWx said:

In that tweet Leon Simons said:

“Tomorrow will be the 500th day in a row of North Atlantic Sea Surface Temperatures running above pre-2023 records. A year ago, many said this was just natural variability. They should come out and eat their shorts.”

 When considering the combination of El Niño and Hunga Tonga (both in the “natural” category), I think it might have been wise to not act so cocky and not act so high and mighty. Is he implying that he knows for sure that AGW/sulfate reduction alone, lead to this sudden jump? If so, how is it possible to be 100% sure?
 

 AGW has caused a much more gradual warming. Also, the reduction in sulfates has caused warming in recent years though nothing big suddenly happened just before 2023. Why would AGW/sulfate reduction suddenly cause this big jump and how could he be so sure that Hunga Tonga, which shot an enormous amount of greenhouse effect water vapor way up into the stratosphere, wasn’t a significant contributor in addition to El Niño? Also, it supposedly will take the rest of this decade before the bulk of that added water falls back to earth. The ongoing effects of Hunga Tonga are still being analyzed! I’m not saying HT has been a significant contributor and I’m not saying the opposite. It is unknown. His cockiness implying everything is already figured out is what bothers me here

This is true. The Hunga eruption is still being widely studied because nothing like that (extreme amount of water vapor injected into the stratosphere) has happened before. Actual long term effects unknown. Then we also had the cumulative VEI 5 Ruang eruptions back in April, which also reached the stratosphere. What role does that play? It’s obviously not going to have the “Pinatubo” effect, but I would think that a cumulative VEI 5 tropical volcanic eruption that reached the stratosphere would have *some* effect….what that effect actually is TBD

[bluewave]

26 minutes ago, snowman19 said:

This is true. The Hunga eruption is still being widely studied because nothing like that (extreme amount of water vapor injected into the stratosphere) has happened before. Actual long term effects unknown. Then we also had the cumulative VEI 5 Ruang eruptions back in April, which also reached the stratosphere. What role does that play? It’s obviously not going to have the “Pinatubo” effect, but I would think that a cumulative VEI 5 tropical volcanic eruption that reached the stratosphere would have *some* effect….what that effect actually is TBD

A recent paper found it had a slight cooling effect on the Southern Hemisphere which only lasted through 2023.

 

https://d197for5662m48.cloudfront.net/documents/publicationstatus/203287/preprint_pdf/44b2ee49f72f9858308861dbd4a9f8ed.pdf