2024-2025 La Nina

[Stormchaserchuck1]

40 minutes ago, michsnowfreak said:

I have the last 5 weak ninas as 2005-06, 2008-09, 2016-17, 2017-18, 2022-23. Of those 5, both 2008-09 & 2017-18 were colder than normal here. But what really stands out with that group is a good December. 

La Nina (general) is a colder composite for you. Here are anti-Strong El Nino's:

The EC is probably a little warmer than that composite, as there is somewhat of a -NAO signal. I think all the 5 Winter's you pointed out were warm on the EC (doesn't mean La Nina is warm, it just means the automatic cold signal in the historical database has some -NAO/-AO influence). 

I would probably push that cold to the Upper Midwest and NW lately, especially for more west-based events. 

[PhiEaglesfan712]

25 minutes ago, michsnowfreak said:

I have the last 5 weak ninas as 2005-06, 2008-09, 2016-17, 2017-18, 2022-23. Of those 5, both 2008-09 & 2017-18 were colder than normal here. But what really stands out with that group is a good December. 

2022-23 is hard to classify (the last 3 years for that matter because the MEI, RONI, and ONI were all out of whack). The MEI had this as a super la nina, but this one peaked earlier in season, and dissipated as the season went on. I have it as a moderate la nina (the RONI splits the difference), same as 2021-22 (since they were pretty much the same la nina, just peaking in between season).

2000-01 would replace 2022-23 in this case, and December 2000 was even better than December 2022. February 2001, 2006, and 2009 all had a snowstorm here at PHL, even though all of them finished above average temperaturewise.

[raindancewx]

It's always amusing how no matter what I say on here the most extreme warm/cold case is what people latch onto. When I talk about 2013-14, it's only as a blend with 2021-22 that I'm interested in it. I don't expect the winter to be very much like 2013-14 by itself. The bulge in warmth isn't quite south of Alaska, it's to the West by the dateline which probably favors more cold Plains than Midwest.

Look at the blend.

That's fairly close to what I expect at 500 mb, although I reserve the right to change my mind by the time I put out my forecast.

[40/70 Benchmark]

6 minutes ago, raindancewx said:

It's always amusing how no matter what I say on here the most extreme warm/cold case is what people latch onto. When I talk about 2013-14, it's only as a blend with 2021-22 that I'm interested in it. I don't expect the winter to be very much like 2013-14 by itself. The bulge in warmth isn't quite south of Alaska, it's to the West by the dateline which probably favors more cold Plains than Midwest.

Look at the blend.

That's fairly close to what I expect at 500 mb, although I reserve the right to change my mind by the time I put out my forecast.

I don't think anyone feels like you expect a repeat of 2013-2014, but given the the last several years, I think the prospect of a compromise between that year and 2021-2022 is alluring to many on the east coast. Even January 2022 had a very nice stetch.

[40/70 Benchmark]

Raindance, your blend looks an awful lot like the CFS.

[40/70 Benchmark]

8 hours ago, brooklynwx99 said:

the CFS is probably the best case scenario for winter lovers in the east... the Aleutian ridge has much more of a poleward component and allows a bit of a +PNA to develop. I am very skeptical of any kind of prolonged +PNA with the state of the PDO, though this does echo Raindance's 2013-14 analog fairly well

 

11 minutes ago, raindancewx said:

It's always amusing how no matter what I say on here the most extreme warm/cold case is what people latch onto. When I talk about 2013-14, it's only as a blend with 2021-22 that I'm interested in it. I don't expect the winter to be very much like 2013-14 by itself. The bulge in warmth isn't quite south of Alaska, it's to the West by the dateline which probably favors more cold Plains than Midwest.

Look at the blend.

That's fairly close to what I expect at 500 mb, although I reserve the right to change my mind by the time I put out my forecast.

 

[raindancewx]

The seasonal models are dumpster fires for winter forecasts at this range. I haven't even really tested the 2013-14, 2021-22 blend yet. It just looks like the SST pattern and seems to have some matching tendencies to recent US conditions. But I haven't subjected the various blends I'm looking at to rigorous testing yet.

[40/70 Benchmark]

Yea, agreed on seasonal models...just interesting when they align with early thoughts.

[chris21]

48 minutes ago, 40/70 Benchmark said:

I don't think anyone feels like you expect a repeat of 2013-2014, but given the the last several years, I think the prospect of a compromise between that year and 2021-2022 is alluring to many on the east coast. Even January 2022 had a very nice stetch.

My wife and I are moving to the NC/Tenn border at 4000 feet. A blend of those two years would bring serious upslope snow to my new location. I think most of the east coast would take that blend at this point.

[GaWx]

Latest (early Sep) ONI runs vs early Aug

UK steady as usual: ~-0.95

JMA dropped from -0.56 to ~-0.9

French dropped from -0.2 to ~-0.65

BoM: dropped from -0.23 to ~-.5

CFS: rose from -1.39 to ~-1.2

 Euro: dropped from -0.29 to ~-0.7

 Last year’s Sep: the UK had been steady then too and was perfect with JMA barely too warm and CFS a bit too cool. Euro was moderately too warm and BoM/French were way too warm.

 Taking all of the above into account, my latest ONI forecast low point is -0.9 to -1.0 and RONI -1.3 to -1.5.

[PhiEaglesfan712]

2021-22 through 2023-24 MEI vs. RONI vs. ONI

2021-22: MEI - Strong/super la nina; RONI - Moderate la nina; ONI - Moderate la nina

2022-23: MEI - Strong/super la nina; RONI - Moderate la nina; ONI - Moderate la nina

2023-24: MEI - Weak el nino; RONI - Moderate/strong el nino; ONI - Strong el nino

[snowman19]

FWIW this is the new C3S snowfall projection for winter

[Stormchaserchuck1]

24 minutes ago, snowman19 said:

FWIW this is the new C3S snowfall projection for winter

I saw this posted too: 

I think the Euro has a 0.65-0.70 seasonal forecast correlation. Even though it had the ridge too far north last Winter, it did come within hundreds of miles of a record breaking ridge that did take place. It also had a good Summer LR forecast for heat in the NE. 

The Euro isn't perfect, but it usually does generally come within a general range area.. that below normal extends up to the Canadian border is a little concerning in the Mid Atlantic. Maybe not so much New England. 

[PhiEaglesfan712]

Last 15 la nina years (grouped by ONI strength)

Weak:

Moderate:

Strong:

[Stormchaserchuck1]

Pretty good -NAO/-AO on the LR 00z GEFS.  This is the only time of year where we don't want it to happen! 

[thunderbolt]

32 minutes ago, Stormchaserchuck1 said:

Pretty good -NAO/-AO on the LR 00z GEFS.  This is the only time of year where we don't want it to happen! 

Same old routine you know what happens come December January February it flips

[bluewave]

13 hours ago, Stormchaserchuck1 said:

I think the cold on the West Coast is partially because we had such a cold trough on the East coast the last few weeks.. We do still need some level of mid latitude cooling in the mix, not just all +pna/-pna.  The heat wave in the SW, US with record streaks of 100+ for Phoenix and Las Vegas will still translate to super warm somewhere as the Fall jet stream gets going. History shows that those conditions there in the Summer do lead to some +PNA conditions in the Wintertime, usually in December, but a lot of times raw temperatures in the SW, US do lead the Midwest and East Coast somewhere down the road.. I'd rather them be cold than warm. 

The key with the La Niña background state and +PNAs is that we need very strong +PNAs to prevent an upper low from undercutting the +PNA ridge. This coming week is an example of the +PNA not being strong enough to prevent the upper low from undercutting the ridge. This is the issue we have had during many recent winters. We need a stronger monthly +PNA to prevent the upper low from undercutting the ridge. 
 

Jan 2023 La Niña and the +PNA was too weak at only +0.21 for the month allowing deep trough underneath and +10 warmest January on record in the Northeast

 

December 2011 +PNA too weak at only +0.36 allowing Baja Trough underneath and one of the warmest Decembers on record

 

Jan 2022+1.01 +PNA allowed heavy snows especially east of NYC

 

Dec 2020 +1.58 +PNA one of the strongest on record allowing historic 40” snow for BGM with -AO

 

[PhiEaglesfan712]

11 hours ago, 40/70 Benchmark said:

I don't think anyone feels like you expect a repeat of 2013-2014, but given the the last several years, I think the prospect of a compromise between that year and 2021-2022 is alluring to many on the east coast. Even January 2022 had a very nice stetch.

So maybe a 1992-93 or 1993-94 type season?

[mitchnick]

8 hours ago, snowman19 said:

FWIW this is the new C3S snowfall projection for winter
 

 

 

 

 

This looks familiar...oh yeah, all the Atlantic hurricane forecasts from 6 months ago.

[susqushawn]

1 hour ago, bluewave said:

The key with the La Niña background state and +PNAs is that we need very strong +PNAs to prevent an upper low from undercutting the +PNA ridge. This coming week is an example of the +PNA not being strong enough to prevent the upper low from undercutting the ridge. This is the issue we have had during many recent winters. We need a stronger monthly +PNA to prevent the upper low from undercutting the ridge. 
 

Jan 2023 La Niña and the +PNA was too weak at only +0.21 for the month allowing deep trough underneath and +10 warmest January on record in the Northeast

 

December 2011 +PNA too weak at only +0.36 allowing Baja Trough underneath and one of the warmest Decembers on record

 

Jan 2022+1.01 +PNA allowed heavy snows especially east of NYC

 

Dec 2020 +1.58 +PNA one of the strongest on record allowing historic 40” snow for BGM with -AO

 

A raging Pac jet tickling the coast certainly doesn't aid in sustaining a +PNA, been a common theme the past several winters.  Ridge rolls over or lops off.  Chill that thing out a bit and hope springs eternal

[FPizz]

8 hours ago, snowman19 said:

FWIW this is the new C3S snowfall projection for winter
 

 

 

 

 

He needs to post more than 1 year to make any type of comparison.   

[PhiEaglesfan712]

3 hours ago, bluewave said:

The key with the La Niña background state and +PNAs is that we need very strong +PNAs to prevent an upper low from undercutting the +PNA ridge. This coming week is an example of the +PNA not being strong enough to prevent the upper low from undercutting the ridge. This is the issue we have had during many recent winters. We need a stronger monthly +PNA to prevent the upper low from undercutting the ridge. 
 

Jan 2023 La Niña and the +PNA was too weak at only +0.21 for the month allowing deep trough underneath and +10 warmest January on record in the Northeast

 

December 2011 +PNA too weak at only +0.36 allowing Baja Trough underneath and one of the warmest Decembers on record

 

Jan 2022+1.01 +PNA allowed heavy snows especially east of NYC

 

Dec 2020 +1.58 +PNA one of the strongest on record allowing historic 40” snow for BGM with -AO

 

PNA stayed negative in January 2023. It didn't turn positive until June.

2022   11  -0.71
2022   12  -0.96
2023    1  -0.37
2023    2  -1.15
2023    3  -1.89
2023    4  -0.65
2023    5  -0.67
2023    6   0.84

[bluewave]

2 hours ago, susqushawn said:

A raging Pac jet tickling the coast certainly doesn't aid in sustaining a +PNA, been a common theme the past several winters.  Ridge rolls over or lops off.  Chill that thing out a bit and hope springs eternal

The last time that raging Pacific Jet was tamed to some extent was way back in January 2022. But it was still a little too strong combined with the +AO so the best snows that January ended up east of NYC rather further west. The storm track was just a little too far east along the East Coast for areas in NJ to do as well as Suffolk County did on Long Island. It was the result of the brief MJO 8 shifting the pattern. But that December 2021 had one of the fastest Pacific Jets and DFW went +13. Then in February it was back to the regularly scheduled fast Pacifc jet programming. In all my years tracking the weather I haven’t seen as hostile a stretch for fast and dominating Pacific flow as we have seen from 18-19 through 23-24. It was like someone flipped a switch after the November 2018 snowstorm.

[PhiEaglesfan712]

31 minutes ago, bluewave said:

The last time that raging Pacific Jet was tamed to some extent was way back in January 2022. But it was still a little too strong combined with the +AO so the best snows that January ended up east of NYC rather further west. The storm track was just a little too far east along the East Coast for areas in NJ to do as well as Suffolk County did on Long Island. It was the result of the brief MJO 8 shifting the pattern. But that December 2021 had one of the fastest Pacific Jets and DFW went +13. Then in February it was back to the regularly scheduled fast Pacifc jet programming. In all my years tracking the weather I haven’t seen as hostile a stretch for fast and dominating Pacific flow as we have seen from 18-19 through 23-24. It was like someone flipped a switch after the November 2018 snowstorm.

The coastal areas, like ACY, fared the best in the snow department in 2021-22. Those were the same areas that did the worst in 2020-21, where the storm tracks seem to be north and west of PHL/I-95.

[bluewave]

18 minutes ago, PhiEaglesfan712 said:

The coastal areas, like ACY, fared the best in the snow department in 2021-22. Those were the same areas that did the worst in 2020-21, where the storm tracks seem to be north and west of PHL/I-95.

It was another case of 60°warmth around the snowstorm in ACY during January 2022 that we have also frequently seen around NYC with our snow events since 2015-2016. The overpowering +PNA and +AO was just a little too progressive west of a line from ACY to FRG and ISP. 

The interior areas like BGM did much better in 2020-2021 due to the south based -AO linking up with the WAR to the east of New England. So the storm track went over ACY instead of ACK especially in that December record snow of 40” for BGM. But the raging Pacific Jet was able to sneak in for the Christmas 2020 flood cuttter a few days later  which caused the flood damage to the ski resorts and they lost the whole snowpack of 40” from a few days earlier. 

[snowman19]

For anyone interested, here is a very good write up by @Isotherm on geomag/solar and the NAO. Also touches on QBO and ENSO influences: 

https://lightinthestorm.com/archives/tag/solar

[bluewave]

2 hours ago, PhiEaglesfan712 said:

PNA stayed negative in January 2023. It didn't turn positive until June.

2022   11  -0.71
2022   12  -0.96
2023    1  -0.37
2023    2  -1.15
2023    3  -1.89
2023    4  -0.65
2023    5  -0.67
2023    6   0.84

The PNA was weakly positive on the CPC site in January 2023.

https://origin.cpc.ncep.noaa.gov/products/precip/CWlink/pna/norm.pna.monthly.b5001.current.ascii.table

 

2023   0.21

[GaWx]

1 hour ago, snowman19 said:

For anyone interested, here is a very good write up by @Isotherm on geomag/solar and the NAO. Also touches on QBO and ENSO influences: 

https://lightinthestorm.com/archives/tag/solar

Since 1979-80, there have been only 6 winters that had a -0.25- NAO:

1984-5: SS 20

1986-7: SS 6

1995-6: SS 12

2009-10: SS 21

2010-1: SS 33

2020-1: SS 14

 So, since 1979-80:

1. NAO winters dropped way down in frequency with only 6 (13%) of 45 following the 25 winters 1954-5 through 1978-9, which had 16 (64%). So, 1979-80 through 2023-4 winters had 1/5 the freq of -NAO winters the prior 25 had

2. All -NAO winters of the last 45 had SS 33 or lower. They averaged 18. 1900+ avg SS: 85. So, the 6 had SS that averaged only 1/5 of the 1900+ avg for all months.

3. Related, the 6 were all within about 2 yrs of min.

4. This graph shows the correlation well:

[bluewave]

28 minutes ago, GaWx said:

Since 1979-80, there have been only 6 winters that had a -0.25- NAO:

1984-5: SS 20

1986-7: SS 6

1995-6: SS 12

2009-10: SS 21

2010-1: SS 33

2020-1: SS 14

What we saw in 20-21 matches the theme of the blocks becoming more AO and KB dominant since the 15-16 super El Niño. Just check out the winter spread between the AO and NAO indices during recent years. Some months had strong -AO readings but hardly registered negative on the NAO scale. Our older stronger -AO winter months usually had a stronger -NAO response also. So a combination of more south based blocks linking up with the Southeast Ridge and lower heights near Iceland. This is why we see that cold pool frequently showing up near Iceland as the winds have increased there over time.
 

 

[michsnowfreak]

21 hours ago, Stormchaserchuck1 said:

La Nina (general) is a colder composite for you. Here are anti-Strong El Nino's:

The EC is probably a little warmer than that composite, as there is somewhat of a -NAO signal. I think all the 5 Winter's you pointed out were warm on the EC (doesn't mean La Nina is warm, it just means the automatic cold signal in the historical database has some -NAO/-AO influence). 

I would probably push that cold to the Upper Midwest and NW lately, especially for more west-based events. 

That's a good point. I did look up 2008-09 and it did seem to average colder than normal on the east coast but not nearly as cold as here. And seems the Feb 2018 torch is what made the difference on the east coast for that winter.