2024-2025 La Nina

[bluewave]

20 hours ago, GaWx said:

1. Yes, 1966 was one of the most skewed of active (ACE of 140+) FULL seasons with ~61% of the 15 storm ACE from just Inez and Faith. However, we don’t yet know how skewed, if at all, 2024 will turn out since the vast majority of the season is still ahead of us ACE climowise (85%). If 2024 ends up near 200, Beryl and Ernesto combined would have no more than 25-30%. And what would the significance of skewed even mean, if anything, if it were to occur?

2. I agree that 1968 can’t reasonably be used as an analog.

3. Yeah, I agree that 2024 is not headed for being another 2005.

4. 1995-6 isn’t a good analog at all due to it having had a +PDO vs the projected strong -PDO/WPAC marine heatwave, it being near solar min vs 2024-25 near max, the strong early winter -AO/-NAO of 1995-6 vs +AO/+NAO expected for 2024-5, and the significant amount of GW since 1995-6.

edit: 1995-6 QBO was slightly E vs projected W of 2024-5.

This will be the first time that such a strong El Niño had this much more tropical development in late August than a La Niña the following season. We were already up to the K storm by the end of August last year. So my guess is that the competing marine heatwaves around the world are altering the typical tropical activity response in recent years. But most years don’t show the peak in activity until September which is still ahead of us. September is when the dust usually relaxes.
 

 

[40/70 Benchmark]

8 hours ago, snowman19 said:

I apologize to everyone. I have been working double shifts at my job for over a year now. Between the wedding and buying a house, my wife and I have been struggling. Over the last week, I’ve been operating on next to zero sleep and my patience with everything has been running thin. Again, my apologies 

Sorry to hear, man.....good luck with everything. This place is a much needed escape from life. I know we don't always see eye to eye (except maybe this season lol), but its never personal.

[40/70 Benchmark]

2 hours ago, snowman19 said:

Let’s see what the EWB does, maybe it triggers another upwelling Kelvin Wave. IMO the worst case scenario for this winter would be Niña fail, central-based cold-neutral ENSO given the predominant MJO 4-6 and the PDO/QBO/solar states

I agree.....ironically enough, eastern winter enthusiasts should be cheering on La Nina because otherwise we are entirely at the mercy of the extra tropical players. That would not leave me super optimistic given the raging solar status, W QBO and that absolutely demonic west PAC warm pool. Perhaps a boneafide La Nina will provide some bouts of poleward Aleutian ridging and an active N stream.

[40/70 Benchmark]

I still expect a healthy moderate Nina per RONI and weak per ONI approaching moderate.

[mitchnick]

9 minutes ago, 40/70 Benchmark said:

I still excepect a healthy moderate Nina per RONI and weak per ONI approaching moderate.

Do you know of anyone (as in model suites) doing Roni predictions like Oni?

[40/70 Benchmark]

2 minutes ago, mitchnick said:

Do you know of anyone (as in model suites) doing Roni predictions like Oni?

@GaWxShowed one like a month ago that I think was posted on X, but he didn't have access to the actual output, if I recall correctly...

[snowman19]

59 minutes ago, bluewave said:

This will be the first time that such a strong El Niño had this much more tropical development in late August than a La Niña the following season. We were already up to the K storm by the end of August last year. So my guess is that the competing marine heatwaves around the world are altering the typical tropical activity response in recent years. But most years don’t show the peak in activity until September which is still ahead of us. September is when the dust usually relaxes.
 
[/url]  

The developing “Atlantic Niña” may be playing a role too

 

 

 

 

[40/70 Benchmark]

3 hours ago, PhiEaglesfan712 said:

The CFS is now showing a cold September, as well as a cool autumn:

 

Its usually fairly accurate within 30 or so days....

[bluewave]

17 minutes ago, 40/70 Benchmark said:

@GaWxShowed one like a month ago that I think was posted on X, but he didn't have access to the actual output, if I recall correctly...

Ben Noll has it on his site. Just open the menu and scroll down.

https://www.bennollweather.com/climate-graphics

 

[40/70 Benchmark]

3 minutes ago, bluewave said:

Ben Noll has it on his site.

https://www.bennollweather.com/climate-graphics

 

Thanks.

Looks like about -1.2 in Novie for a peak.

[mitchnick]

22 minutes ago, snowman19 said:

The developing “Atlantic Niña” may be playing a role too

 

 

 

 

Perfect example of why there are no slam dunks in weather, especially seasonal outlooks.

[FPizz]

1 minute ago, mitchnick said:

Perfect example of why there are no slam dunks in weather, especially seasonal outlooks.

It is cooler, but does 1.8 degrees F (in the coldest dot on that map) really mean that much?  What is the actual water temp there, for most of that whole blue area it is actually less than 1 degree different.

[40/70 Benchmark]

On 8/3/2024 at 8:45 PM, snowman19 said:

Was looking at it more today, if there is a Niña, I’m starting to think ONI stays weak, which wouldn’t make 07-08 (I know Ray likes that one) and 16-17 bad. The big problem with 16-17 is the PDO and PMM don’t match (both were positive back then), the +QBO does match however as does the -IOD, +AMO and the MJO 4-6 Niña forcing. The best solar match is still 01-02, very good solar match actually and if it stays cold-neutral would definitely be a good ENSO match and would also match all the other background states we have now

 

 

 

 

1970 is a pretty good solar match, too.

[40/70 Benchmark]

On 8/4/2024 at 5:09 PM, Stormchaserchuck1 said:

Yeah it's pretty high up there on the probability of happening. Here is the final Dec - July map:

So the analogs fit.. I think it was 25 of the 30 that continued the same direction very consistently through the following March (out of 75).  

The central-ENSO subsurface is still posting -6c readings, meaning that water temps there are 12c vs what we saw this time a year ago of 21-22c! There is a -PNA effect in the N. Pacific pattern with those cold subsurface waters..

30mb QBO came in +12.53 for August.. so that is heading toward another strong phase in the Fall and Winter... that is my hesitation on a cold Dec, I think -QBO and La Nina favors cold Decembers but not +qbo. The stronger/faster Polar Vortex at 10mb, has a pretty direct effect to the surface around the Winter solstice. Also, we set some precedents in Dec 2021 when the -PNA hit 600dm. That longer term -PNA phase that is still progressing during that month. 

Because of above normal precip probability, I still like the Great Lakes and interior NE for snow, but now way down here.. -PNA/+NAO is the worst pattern probably besides +EPO. If those storms cut up through the Ohio Valley like I think, we could see a lot of days in the 60s. Of course, there is still the wild card/potential variable that the EPO flips to negative.. I'd give the chance of that happening for the Winter at 15% (13-14 analog) and 20% of a less extreme version of 13-14, which is actually high considering the alternative. I don't think that we'll have another +WPO Winter (5 of the last 6 Winters have been +WPO).  

Then was have central-based La Ninas favoring the coldest month and least+NAO in Deceber, so I think the perponderance of the data favors more of a nomralish month of December rather than cold, before the wheels come off mid-season.

[40/70 Benchmark]

On 6/27/2024 at 12:35 AM, GaWx said:

 With an open mind due to curiosity, I did my own analysis of objective ENSO/Solar/QBO data back to 1958:

 1) First of all, is La Niña/W QBO really extra favorable for major SSWs?

La Niña/W: 5 major SSWs (2/26/99, 3/20/00, 1/24/09, 1/5/21, 2/16/23)

La Niña/E: 5 major SSWs (1/20/71, 2/24/84, 2/11/01, 1/21/06, 2/12/18)

El Nino/W: 5 major SSWs (1/30/58, 12/8/87, 3/14/88, 2/24/07, 1/2/19)

El Nino/E: 12 major SSWs (11/30/58, 12/16/65, 2/23/66, 11/29/68, 1/9/77, 2/29/80, 1/23/87, 2/9/10, 3/24/10, 1/16/24, 2/18/24, 3/4/24)

 Thus, I see no evidence that La Niña/W QBO is extra favorable for major SSWs. The only one of the four combos analyzed that clearly is extra favorable for major SSWs is El Niño/E QBO, like we had last winter and hopefully will again during the winter of 2025-6.

 
2) Secondly, were the five La Niña/W major SSWs mainly near solar max?

-Feb 1999: sunspots 98 and ~halfway between min and max. This, I consider this neutral solar.

-Mar 2000: sunspots 218/1 yr pre solar max

-Jan 2009: sunspots 1/solar min

-Jan 2021: sunspots 10/1.5 yr post solar min

-Feb 2023: sunspots 111/2 yrs pre solar max

 So, there was a mix and the avg sunspots of the 5 was 88, which is near longterm mean. Thus, I see no evidence of increased chance of major SSWs when La Niña/W is near solar max.

 To be clear, this analysis isn’t suggesting having a major SSW this winter is unlikely. Rather, it suggests it isn’t likely either and is instead only about a coin flip even with solar max. There have been 8 La Niña West winters since 1957-8: 1971-2, 1975-6, 1999-00, 2008-9, 2010-1, 2016-7, 2020-1, and 2022-3. So, 4 of these 8 (50%) La Niña/W winters had a major SSW.
 
  Out of curiosity, I decided to calculate the % of El Niño/E winters with at least one major SSW. These are the El Niño/E winters since 1957-8: 1958-9, 1965-6, 1968-9, 1976-7, 1979-80, 1986-7, 1991-2, 2009-10, 2014-5, and 2023-4. So, of these 10 El Niño/E winters, a whopping 8 (80%) had at least one major SSW! And the ratio of 12 majors during these 10 winters is even more impressive thanks to 3 of the 10 winters having 2+ of them! Thus, that’s even more reason to hope for El Niño next winter.

——————————————
 Edit: What % of La Niña/E winters had at least one major SSW? These were the 10 La Niña/E winters since 1957-8: 1970-1, 1974-5, 1983-4, 1995-6, 2000-1, 2005-6,  2007-8, 2011-2, 2017-8, and 2021-2. So, like for La Niña/W, half (5 of 10) of those had an SSW.

 What % of El Niño/W winters had 1+ SSWs? These were the 9 El Niño/W winters: 1957-8, 1963-4, 1977-8, 1982-3, 1987-8, 1994-5, 2006-7, 2015-6, and 2018-9. Out of the 9, 4 (44%) had at least one major SSW.

———————-

Data sources:  

ENSO https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php

Solar (monthly sunspots): https://www.sidc.be/SILSO/DATA/SN_m_tot_V2.0.txt

QBO (30 mb): https://psl.noaa.gov/data/correlation/qbo.data

Major SSW events (plus I added 2023 and 2024 events) https://en.m.wikipedia.org/wiki/Sudden_stratospheric_warming

@snowman19

There is actually somewhat of a signal for late season SSW during La Nina/W QBO seasons...February and March.

[snowman19]

1 hour ago, 40/70 Benchmark said:

There is actually somewhat of a signal for late season SSW during La Nina/W QBO seasons...February and March.

The Nina’s with +QBO/low solar are, the ones with high solar are the least, obviously Nina’s with -QBO/low solar are the most

[40/70 Benchmark]

19 minutes ago, snowman19 said:

The Nina’s with +QBO/low solar are, the ones with high solar are the least, obviously Nina’s with -QBO/low solar are the most

There is actually a pretty solid grouping.

https://easternmassweather.blogspot.com/2024/08/preliminary-analysis-of-polar-domain.html

 

These relationships between solar behavior and the NAO are evident in the graph above, with reds, denoting +NAO, very evident in the declining phase of the last several solar cycles. And Blue, indicative of -NAO, prevalent in the ascending portion of the cycles. What can also be deduced from the graphic above is that while solar max seasons are not as favorable as the ascending phase of the cycle for incidences of high latitude blocking, nor are they as hostile as the descending seasons. Thus winter seasons such as 2024-2025, which are near solar max, are not entirely void of blocking. This is evident when considering the best solar analogs of 1970 and 1999.

 

There was a split of the polar vortex on January 17, 1971, a displacement on March 20, 1971 and a displacement on March 20, 2000. While there was an easterly QBO evident during the 1970-1971 winter, the polar vortex displacement that took place in March of 2000 occurred during a westerly QBO, as will be the case this season. Thus the latter displacement seems worthy of more consideration for the coming season. When considering the three primary QBO analogs of 2016, 2020 and 2022 within a solar context, although none took place during solar max, 2022 was the closest, followed by 2016 and 2020, which is a poor solar match having taken place near solar minimum.

 

Given that the QBO analog of 2020-2021 took place near solar minimum, the early January 2021 SSW  is of least relevance as a viable analog occurrence this season. However, the February 2023 SSW, which is a better solar analog, lends more support to a later season potential polar vortex disruption along the lines of March 1971 and 2000. This notion is supported by research on high solar, westerly QBO seasons, which lends creedence the late winter/early spring displacement scenario.

 

 

 

 

The postulation of a modestly disturbed polar vortex during the month of December, followed by a recovery during the middle portion of the winter, prior to a more substantial displacement of the polar vortex during either February or March is well supported by research on moderate, basin-wide La Niña events taking place near a solar maximum with a westerly QBO. This preliminary conclusion based upon a constellation of historic data can be checked against observed, concurrent data in real time.

[40/70 Benchmark]

Started looking at the extra tropical pacific a bit today...everything considered, I really like 2022 as an analog....and as bad as that season was, it defenitely left something on the table for the east coast. December and March could have been significantly better.

[GaWx]

6 hours ago, PhiEaglesfan712 said:

The CFS is now showing a cold September, as well as a cool autumn:

 

1. The WeatherBell versions of the CFS are highly flawed as has been shown repeatedly here. For example, they almost always show a relatively cold spot near Chicago and a much warmer spot in or near N Michigan.

2. To show that the WB 0Z 8/16 CFS (the run you’re showing) is way too cold in the E US, it has DC ~6.5F BN vs 1991-2020 for the next 5 days:

  The 1991-2020 normal DC for 8/16-20 is a high of 88, low of 71, and mean of 79.5:

https://www.weather.gov/wrh/Climate?wfo=lwx

 So, the WB 0Z 8/16 CFS for 8/16-20 has DC at 79.5 - 6.5 = 73.0

 But per DC NWS predictions, the avg high/low forecasted for 8/16-20 is ~85/70 or a mean of ~77.5 or only 2 BN vs the WB CFS map’s 6.5 BN!

DISTRICT OF COLUMBIA-  

INCLUDING THE CITY OF WASHINGTON  

1032 AM EDT FRI AUG 16 2024  

   

REST OF TODAY  

PARTLY SUNNY. HIGHS AROUND 90. SOUTH WINDS 5 TO  

10 MPH.    

TONIGHT  

MOSTLY CLOUDY. SCATTERED SHOWERS WITH ISOLATED  

THUNDERSTORMS AFTER MIDNIGHT. LOWS IN THE LOWER 70S. SOUTH WINDS  

5 TO 10 MPH. CHANCE OF RAIN 40 PERCENT.    

SATURDAY  

MOSTLY CLOUDY WITH A CHANCE OF THUNDERSTORMS. A  

CHANCE OF SHOWERS. HIGHS IN THE MID 80S. SOUTH WINDS AROUND  

10 MPH. CHANCE OF RAIN 50 PERCENT.    

SATURDAY NIGHT  

MOSTLY CLOUDY WITH A CHANCE OF THUNDERSTORMS. A  

CHANCE OF SHOWERS. LOWS IN THE LOWER 70S. SOUTH WINDS 5 TO  

10 MPH. CHANCE OF RAIN 50 PERCENT.    

SUNDAY  

MOSTLY CLOUDY IN THE MORNING, THEN BECOMING PARTLY  

SUNNY. A CHANCE OF THUNDERSTORMS. A CHANCE OF SHOWERS IN THE  

MORNING, THEN SHOWERS IN THE AFTERNOON. HIGHS IN THE UPPER 80S.  

SOUTH WINDS 5 TO 10 MPH. CHANCE OF RAIN 90 PERCENT.    

SUNDAY NIGHT  

MOSTLY CLOUDY WITH A CHANCE OF SHOWERS AND  

THUNDERSTORMS. LOWS AROUND 70. CHANCE OF RAIN 40 PERCENT.    

MONDAY  

SHOWERS LIKELY WITH A CHANCE OF THUNDERSTORMS. HIGHS IN  

THE MID 80S. CHANCE OF RAIN 60 PERCENT.    

MONDAY NIGHT  

MOSTLY CLOUDY. LOWS IN THE MID 60S.    

TUESDAY  

MOSTLY SUNNY. HIGHS IN THE UPPER 70S.

———————————

3. To show that it’s not the CFS, itself, but the WB CFS map algorithms that are the big problem, here is the avg of the last 12 runs of the CFS on TT for 8/16-22, which has NN at DC:

 
In stark contrast the WB 0Z 8/16 CFS run for 8/16-22 is off the deep end with a whopping 8F BN there with other recent runs similarly cold:

 

4. In stark contrast to the cold WB 0Z 8/16 CFS for autumn, here’s the avg of the last 12 TT CFS runs for the upcoming autumn:

[40/70 Benchmark]

I think there is a decent shot of:

1) The PV beginning the season somewhat weak before going to town.

2) A pretty major disruption in February-March, however, whether or not the coast reaps the benefits of said disruption is somewhat dubious.

[michsnowfreak]

14 hours ago, Stormchaserchuck1 said:

1959 (59-60)

1963 (63-64)

1965 (65-66)

1978 (78-79)

1994 (94-95)

1996 (96-97)

2003 (03-04)

2004 (04-05)

2009 (09-10)

2014 (14-15)

Thank you. But my apologies, I meant what does "minus" mean? They are still an analog just not as good of one? I used to think minus meant you wouldnt want to include it in a dataset lol.

[michsnowfreak]

7 minutes ago, 40/70 Benchmark said:

Started looking at the extra tropical pacific a bit today...everything considered, I really like 2022 as an analog....and as bad as that season was, it defenitely left something on the table for the east coast. December and March could have been significantly better.

Definitely not a favorite winter of mine, but wasnt terrible by any means here. Dec 2022 had the huge arctic blast at Christmas time. And March was snowy.

[40/70 Benchmark]

5 minutes ago, michsnowfreak said:

Thank you. But my apologies, I meant what does "minus" mean? They are still an analog just not as good of one? I used to think minus meant you wouldnt want to include it in a dataset lol.

Its means its an "antilog"....IOW, opposite pattern to what is expected. This is why Raindance is always meantioning great east coast snowfall years as antilogs over the course of the last several years.

[michsnowfreak]

1 minute ago, 40/70 Benchmark said:

I think theere is a decent shot of:

1) The PV beginning the seasons somewhat weak before going to town.

2) A pretty major disruption in February-March, however, whether or not the coast reaps the benefits of said disruption is somewhat dubious.

I have had a feeling for a while that December may be one of the best months of the winter this year, at least here. Its been a while since December was THE month of the winter, and its also common to happen in Ninas. Doesnt always happen that way of course (1998-99, a terrible Dec and excellent Jan). One thing about a Nina is that most of them feature one unusually snowy month.

[brooklynwx99]

10 minutes ago, 40/70 Benchmark said:

Started looking at the extra tropical pacific a bit today...everything considered, I really like 2022 as an analog....and as bad as that season was, it defenitely left something on the table for the east coast. December and March could have been significantly better.

yeah, that pattern at the end of December could easily have produced a major storm. TPV just phased in over the Rockies… I would certainly roll the dice with that setup again

[40/70 Benchmark]

2 minutes ago, brooklynwx99 said:

yeah, that pattern at the end of December could easily have produced a major storm. TPV just phased in over the Rockies… I would certainly roll the dice with that setup again

I know that Bluewave is going to come in and say it didn't work out because of the low heights out west due in part to the West Pac warm pool, but I think its a bit more nuanced than that....its more of an uphill battle than it was 50 years ago to be sure, but make no mistake about it....that still could have worked out and there was some bad luck involved, too.

[40/70 Benchmark]

Not my first choice, but I will roll the dice again with a set up similar to 2022-2023...especially where I am. Not so much significantly to my south...

[Terpeast]

1 hour ago, brooklynwx99 said:

yeah, that pattern at the end of December could easily have produced a major storm. TPV just phased in over the Rockies… I would certainly roll the dice with that setup again

Agreed. We were robbed there by something like the butterfly effect. I remember a few model runs showing foot-plus snows in the MA before we got rug pulled. 

[snowman19]

[GaWx]

3 hours ago, 40/70 Benchmark said:

There is actually somewhat of a signal for late season SSW during La Nina/W QBO seasons...February and March.

I don’t disagree. My post you quoted lists 3 Niña W seasons with a major Feb-Mar SSW: 2/26/99, 3/20/00, and 2/16/23 vs 2 earlier in the winter (in Jan). So, this suggests there may be a modest lean toward late season vs earlier for Niña W. It also suggests there may be a slightly higher tendency to late major SSW during Niña W vs Nino W, which had only 2 of 5 during Feb-Mar.

 Nina E is similar to Niña W’s with 3 in Feb and 2 in Jan fwiw though none in March. The 3 in Feb were on 2/11, 2/12, and 2/24. So, Niña W’s late SSWs have averaged 2 weeks later than Niña E’s late ones fwiw.

 There have been 8 La Niña West winters during the period being analyzed. So, 3 of these 8 had a Feb or Mar major SSW, a respectable portion.

 Regardless of any tendency toward late vs earlier season major SSW during Niña W, Nino E has had more late. There have been 10 Nino E seasons during the analyzed period. Nino E has had 6 Feb-Mar major SSWs with two seasons having two: 

2/23/66, 2/29/80, 2/9/10, 3/24/10, 2/18/24, and 3/4/24

 So, if I’m ranking tendency toward a late season major SSW, I’d rank them this way from highest to lowest:

Nino E, Niña W, Niña E, Nino W