2024-2025 La Nina

[40/70 Benchmark]

12 hours ago, raindancewx said:

May-July looks a bit like a blend of 1999, 2020, 2022 globally at 500 mb.

I like all of those analog years.

[snowman19]

1 hour ago, 40/70 Benchmark said:

Def. grain of salt after reading this site last season and then seeing how the winter evolved....but does lend creedence to my idea that the winter shouldn't be wall-to-wall ++AO/NAO....
https://www.severe-weather.eu/long-range-2/south-pole-stratospheric-warming-winter-2024-2025-influence-forecast-united-states-canada-europe-fa/
Main points:

1. A strong stratospheric warming event is ongoing over the South Pole. It will disrupt the southern polar vortex and help to create and sustain high-pressure anomalies on the surface.
2. The south pole pressure forecast for August-October shows a prolonged period of high-pressure anomalies, creating a negative circulation pattern.
3. Past data and studies show that prolonged high-pressure anomalies over the South Pole in the August-Oct period can influence the weather over the Northern Hemisphere in the following weeks/months.
4. The most likely cause of the weather impacts is the stratospheric connection between the northern and southern polar vortex that helps to transfer the atmospheric dynamics.
5. The prevalent signal in the data shows that strong high-pressure anomalies over the South Pole in the August-Oct period correspond to lower pressure anomalies over the United States and Canada in the Winter season. The data also shows colder-than-normal temperatures over much of the central and eastern parts of the United States.
6. Over Europe, the prevailing signal is a high-pressure anomaly and warmer temperatures during the Winter season.
7. The main final point: These signals and connections are not a fixed rule, as the signal is weak enough to indicate it is not a main (large) driving force of the Winter weather patterns. But it is still visible and does show some form of a role in the overall large-scale atmospheric circulation.

Was looking at that last week. We saw the same thing in July of 2011, 2007, 2001, 1995, 1992, 1991 and 1980. Not sure about 1980 but I think the others did have some AO disruption. 95 obviously did

 

 

 

 

[40/70 Benchmark]

41 minutes ago, snowman19 said:

Was looking at that last week. We saw the same thing in July of 2011, 2007, 2001, 1995, 1992, 1991 and 1980. Not sure about 1980 but I think the others did have some AO disruption 

 

 

 

 

1991, 1992 and 2011 didn't, although the former two were directly following Pinatubo, so bit of an asterisk there.

Obviously the winter is very likely to average a +NAO and probably AO, but I think what this means is we may see at least one month with decent blocking, which jives with my early inclination from looking at analogs.

[snowman19]

2 hours ago, 40/70 Benchmark said:

I haven't seen anyone suggest a cold December.....what I have seen is the suggestion that it will be the one month featuring temps relatively close to normal during a very mild winter.

I never said anyone was, just responding to Chuck’s point about the QBO rise from June to July and December, nothing more. I suspect we see a strong +QBO in the next several months given that July is already up to over +12 and it just turned positive in June. Whether it’s a big factor in the grand scheme of things, I don’t know

[40/70 Benchmark]

1 hour ago, snowman19 said:

I never said anyone was, just responding to Chuck’s point about the QBO rise from June to July and December, nothing more. I suspect we see a strong +QBO in the next several months given that July is already up to over +12 and it just turned positive in June. Whether it’s a big factor in the grand scheme of things, I don’t know

Yes, it will def. be a strong westerly QBO..

[Stormchaserchuck1]

9 hours ago, bluewave said:

July 2024 has just set the new July all-time monthly +PNA record at +2.60.

Weird..

[PhiEaglesfan712]

MJJ ONI (NOAA): +0.2C

MJJ RONI: -0.38C

[mitchnick]

August Euro Seasonal out today...as expected.

https://charts.ecmwf.int/?facets={"Product type"%3A[]%2C"Parameters"%3A[]%2C"Range"%3A["Long (Months)"]%2C"Type"%3A[]}

[Stormchaserchuck1]

18 minutes ago, mitchnick said:

August Euro Seasonal out today...as expected.

https://charts.ecmwf.int/?facets={"Product type"%3A[]%2C"Parameters"%3A[]%2C"Range"%3A["Long (Months)"]%2C"Type"%3A[]}

Looks like -PNA/+NAO

Euro seasonal actually did very good about the hot Summer in the NE this year from this range. 

They were pretty far off about a cooler Winter last year in the east.. it has a heavy ENSO bias

[raindancewx]

I suspect the extreme rain event for the East, in this time frame (August) is a useful signal for the winter. But I haven't looked at it yet. 

[snowman19]

4 hours ago, PhiEaglesfan712 said:

MJJ ONI (NOAA): +0.2C

MJJ RONI: -0.38C

Very slow to develop. Cold-neutral (at the very least) is a guarantee, I still think there’s an official La Niña. Also, still no sign of an east-based event developing; i.e. 2017. I think twitter can put the east-based fantasies to bed now IMO

[George001]

23 minutes ago, snowman19 said:

Very slow to develop. Cold-neutral (at the very least) is a guarantee, still think there’s a La Niña. Also, no sign of an east-based event developing; i.e. 2017. I think twitter can put the east-based fantasies to bed now IMO

I’m thinking a borderline weak/moderate ONI event that is basinwide as of right now. However, in the event that I’m wrong and the Nina fails to develop, what about 2012-2013 as a possible analog? That was a strongly -PDO (close to -3) summer, and the -PDO continued into winter. It was cold neutral too. Not saying we should expect the same results, but overall a less extreme version of last years warm + wet combo makes sense. Something like +2 to +3 AN temps instead of +5, and a wetter than average winter but drier than last year. Actually the more I look into it, the more I like your 2016-2017 analog. 

[snowman19]

14 minutes ago, George001 said:

I’m thinking a borderline weak/moderate ONI event that is basinwide as of right now. However, in the event that I’m wrong and the Nina fails to develop, what about 2012-2013 as a possible analog? That was a strongly -PDO (close to -3) summer, and the -PDO continued into winter. It was cold neutral too. Not saying we should expect the same results, but overall a less extreme version of last years warm + wet combo makes sense. Something like +2 to +3 AN temps instead of +5, and a wetter than average winter but drier than last year. Actually the more I look into it, the more I like your 2016-2017 analog. 

I don’t like 12-13. QBO and solar don’t fit. Even 16-17, PDO/PMM don’t fit. The high solar flux and geomag is going to play a bigger role in this winter than some people are giving it credit for. Ignore this at your own risk (ghost of 2001):

 

 

 

 

[michsnowfreak]

21 hours ago, Stormchaserchuck1 said:

Wonder if you've seen the CPC's DJF forecast. Looks pretty good for you. 

Definitely like that outlook lol

[BuffaloWeather]

On 7/29/2024 at 10:15 PM, roardog said:

If I recall correctly there actually was a -NAO block in the second half of December 2001. Canada was still filled with relatively mild air though which only allowed the US to get near average cold. I remember there being a huge SW flow lake effect snow event which buried Buffalo since the water was mild from the warm November and first half of December. 

Such a fun week. That week alone made winter an A+.

https://www.weather.gov/buf/lesEventArchive?season=2001-2002&event=B

 

[bluewave]

15 hours ago, Stormchaserchuck1 said:

Weird..

This was actually the 2nd highest monthly +PNA on record leading to the record heat over Western North America. Very impressive that 5 of the strongest monthly +PNA readings were July La Ninas.
 

Top 10 monthly +PNA readings with La Niña Julys bolded

+2.66….. MAY…1993

+2.60…..JUL….2024

+2.54…..JUL….2022

+2.47..…JAN…..1981

+2.38…MAR……1983

+2.24…JUL…….1998

+2.22…AUG……1977

+2.21….JUL……2007

+2.16…..JUL…..1988

+2.16…..JAN….2016

 

 

[mitchnick]

11 hours ago, raindancewx said:

I suspect the extreme rain event for the East, in this time frame (August) is a useful signal for the winter. But I haven't looked at it yet. 

The models are looking like the ghost of Floyd around here, but that was 9/99 not August. 

[PhiEaglesfan712]

50 minutes ago, bluewave said:

This was actually the 2nd highest monthly +PNA on record leading to the record heat over Western North America. Very impressive that 5 of the strongest monthly +PNA readings were July La Ninas.
 

Top 10 monthly +PNA readings with La Niña Julys bolded

+2.66….. MAY…1993

+2.60…..JUL….2024

+2.54…..JUL….2022

+2.47..…JAN…..1981

+2.38…MAR……1983

+2.24…JUL…….1988

+2.22…AUG……1977

+2.21….JUL……2007

+2.16…..JUL…..1988

+2.16…..JAN….2016

 

 

I'm going to assume that one of those 1988's is supposed to be a 1998. If that's the case, then all of those +PNA Julys produced a strong la nina, with the exception of 2022 (which was a 3rd straight moderate la nina year). Of course, 2022 was the only one that didn't transition from an el nino the previous year. So, we'd be breaking some trends if we don't get a strong la nina out of this.

[mitchnick]

13 minutes ago, mitchnick said:

The models are looking like the ghost of Floyd around here, but that was 9/99 not August. 

Hmmmm....just checked 8/99 at BWI and it had a 3 consecutive day rain event that totaled 4.15". Not quite as much as Floyd's 5.8", but a big total nonetheless. 

I'll vote 99' to Raindancewx's query. 

[bluewave]

Euro seasonal first guess for DJF is similar to the recent winter decadal pattern. Strong Aleutian ridge and Southeast ridge couplet. So places like NYC are probably looking at the record 10th consecutive warmer winter since 15-16.

 

 

 

 

[roardog]

9 hours ago, snowman19 said:

I don’t like 12-13. QBO and solar don’t fit. Even 16-17, PDO/PMM don’t fit. The high solar flux and geomag is going to play a bigger role in this winter than some people are giving it credit for. Ignore this at your own risk (ghost of 2001):

 

 

 

 

What was the QBO in 01-02?

[snowman19]

11 minutes ago, roardog said:

What was the QBO in 01-02?

Rising. Turning positive

[PhiEaglesfan712]

45 minutes ago, mitchnick said:

Hmmmm....just checked 8/99 at BWI and it had a 3 consecutive day rain event that totaled 4.15". Not quite as much as Floyd's 5.8", but a big total nonetheless. 

I'll vote 99' to Raindancewx's query. 

2011 is another year that had a rainy August-September. Oddly enough, both 1999 and 2011 led into 2nd year la ninas.

[mitchnick]

41 minutes ago, PhiEaglesfan712 said:

2011 is another year that had a rainy August-September. Oddly enough, both 1999 and 2011 led into 2nd year la ninas.

Yes, that qualifies as well. I prefer 99/00 winter, however.  

[snowman19]

1 hour ago, PhiEaglesfan712 said:

2011 is another year that had a rainy August-September. Oddly enough, both 1999 and 2011 led into 2nd year la ninas.

Aug-Sept 2011 was an epic deluge largely thanks to Irene. Soil moisture was well over 200% of average in September 

[40/70 Benchmark]

2 hours ago, bluewave said:

Euro seasonal first guess for DJF is similar to the recent winter decadal pattern. Strong Aleutian ridge and Southeast ridge couplet. So places like NYC are probably looking at the record 10th consecutive warmer winter since 15-16.

 

 

 

 

One thing I will say is that EURO product looks to have a pretty poleward Aleutian ridge...more stout than the 2016-2024 mean.

[40/70 Benchmark]

43 minutes ago, mitchnick said:

Yes, that qualifies as well. I prefer 99/00 winter, however.  

1999 is a better analog then 2011.

[PhiEaglesfan712]

I still think the anti-1986 scenario is in play, where we get a strong la nina, but it peaks in the summer of 2025 rather than in the winter. If this happens, then how fast the la nina dissipates in 2026 will be key on whether we have an el nino in 2026-27, and how strong it will be.

One thing to keep in mind is that la ninas are much harder to dissipate than el ninos. Perhaps the biggest reason why we were able to get a historic la nina in 1988-89 is the fact that the el nino that peaked in the summer of 1987 quickly dissipated starting in early 1988.

[bluewave]

53 minutes ago, 40/70 Benchmark said:

One thing I will say is that EURO product looks to have a pretty poleward Aleutian ridge...more stout than the 2016-2024 mean.

This current August forecast for the DJF looks like a blend of the most recent La Niña forecasts from Aug 20,21, and 22. 
 

[40/70 Benchmark]

14 hours ago, Stormchaserchuck1 said:

Looks like -PNA/+NAO

Euro seasonal actually did very good about the hot Summer in the NE this year from this range. 

They were pretty far off about a cooler Winter last year in the east.. it has a heavy ENSO bias

Its good when its warm for the east, bad when its cold...sounds reductive, but that philosophy if fail-proof over the past 9 years.