2024-2025 La Nina

[GaWx]

1 hour ago, PhiEaglesfan712 said:

I think most reasonable people knew this was going to be a -PDO winter, and likely a record -PDO. The only ones that thought otherwise were probably the CanSIPS and the people pushing 2013-14 as a good analog. 

I could tell early on that 2013-14 wasn't going to be a good analog. In 2013, the PDO was (generally) heading towards neutral. This year, the PDO has only gotten deeper into the negative. Maybe 2013-14 could be a good analog for 2025-26, but definitely not this winter.

2013 -1.10 -1.42 -1.48 -0.72 -0.40 -1.19 -1.34 -1.56 -1.00 -1.65 -1.09 -1.04

2024 -1.55 -1.33 -1.52 -2.12 -2.99 -3.16 -2.99 -2.91 -3.54

 Actually, CANSIPS has also been showing a strong -PDO.
 
 The only maps I’ve seen not showing a strong -PDO this winter are the heavily flawed WxBell CFS maps, which have on several occasions already been shown to be garbage and are far different from other versions of the same model! They were even showing a +PDO for this winter, which was getting JB excited and posting them. However, they’ve since backed down to neutral (though that’s still WAY off) as we’ve gotten closer due to the partial correction of the flawed maps. That’s why JB has recently not been as vocal about a possible +PDO this winter. However, WB CFS still show a +PDO but now not til spring (WPAC marine heatwave gone lmao) while TT CFS show no such thing. The flawed WB algorithms won’t allow the entire runs to avoid getting rid of the marine heatwave and showing a +PDO:

WB CFS for Apr 2025: WPAC marine heatwave magically gone with fake strongly BN blue/green area covering much of WPAC:

 

TT CFS for Apr 2025: WPAC marine heatwave intact and AN where WB has strong BN on the SAME model with similar base climo:

 

@donsutherland1

[qg_omega]

1 hour ago, 40/70 Benchmark said:

This is why the PDO is near record negative territory despite the warmth off of the California coast, which is traditonally indicative of a +PDO. It’s becoming increasingly important for forecasters to assume a wholistic approach in global analysis because the unprecedented degree of warmth around the planet is limiting how much can be gleaned from focusing on any single node or geographical area. Whereas in the past we focused on areas of warmth in our assessment of the anticipated pattern it has now becoming apparent that relativity is of the utmost importance since the planet is a sea of warmth. This is the flawed lens through which I viewed ENSO last season. I focused on the orientation of SSTs within the ENSO region when there was larger pool of greater warmth to the west. The warmth off of the CA coast this year represents a similar trap with respect to the PDO.

The maritime heatwaves have overwhelmed the winter patterns.  You need record levels of countering indices to try and get a favorable window for winter weather in the East

[Typhoon Tip]

1 hour ago, 40/70 Benchmark said:

This is why the PDO is near record negative territory despite the warmth off of the California coast, which is traditonally indicative of a +PDO. Its becoming increasingly important for forecasters to assume a wholistic approach in global analysis because the unprecedented degree of warmth around the planet is limiting how much can be gleaned from focusing on any single node or geographical area. Whereas in the past we focused on areas of warmth in our assessment of the anticipated pattern it has now becoming apparent that relativity is of the utmost importance since the planet is a sea of warmth. This is the flawed lens through which I viewed ENSO last season. I focused on the orientation of SSTs within the ENSO region when there was larger pool of greater warmth to the west. The warmth off of the CA coast this year represents a similar trap with respect to the PDO.

great post!

this could have been considered/visualized 10 or 15 years ago but ... seasonal forecasting is a bit of an evolution requirement i suppose

[40/70 Benchmark]

2 hours ago, Typhoon Tip said:

great post!

this could have been considered/visualized 10 or 15 years ago but ... seasonal forecasting is a bit of an evolution requirement i suppose

Well, the counter point of view is that we should be skeptical of large scale continuity shifts in the way that we devise these seasonal formulations and couple this with the inate resistance to change that most humans possess...and yea, some busted seasonals over the course of the past few years.

[donsutherland1]

37 minutes ago, GaWx said:

 Actually, CANSIPS has also been showing a strong -PDO.
 
 The only maps I’ve seen not showing a strong -PDO this winter are the heavily flawed WxBell CFS maps, which have on several occasions already been shown to be garbage and are far different from other versions of the same model! They were even showing a +PDO for this winter, which was getting JB excited and posting them. However, they’ve since backed down to neutral (though that’s still WAY off) as we’ve gotten closer due to the partial correction of the flawed maps. That’s why JB has recently not been as vocal about a possible +PDO this winter. However, WB CFS still show a +PDO but now not til spring (WPAC marine heatwave gone lmao) while TT CFS show no such thing. The flawed WB algorithms won’t allow the entire runs to avoid getting rid of the marine heatwave and showing a +PDO:

WB CFS for Apr 2025: WPAC marine heatwave magically gone with fake strongly BN blue/green area covering much of WPAC:

 

TT CFS for Apr 2025: WPAC marine heatwave intact and AN where WB has strong BN on the SAME model with similar base climo:

 

@donsutherland1

Given how flawed the maps are and how obvious the flaws are when the maps are compared to those from other sources, it is almost inexplicable that WB hasn't tried to fix the problem.

[snowman19]

39 minutes ago, donsutherland1 said:

Given how flawed the maps are and how obvious the flaws are when the maps are compared to those from other sources, it is almost inexplicable that WB hasn't tried to fix the problem.

Done purposely. Wxbell/JB wants the all their flawed maps so they can hype a cold and snowy east coast winter year after year and feed their weenie base for subscription money. That’s the only way they are able to survive…..hyping a cold/snowy east coast and denying climate change. 99% of their paid subscribers are I-95 weenies. They are laughing all the way to the bank

[michsnowfreak]

15 hours ago, donsutherland1 said:

I suspect that this winter will see more variability than the last two. December might actually do well for snowfall in the Great Lakes region with a storm track that cuts toward and east of the Lakes. Some La Niña events have seen healthy snowfall from Chicago to Toronto in December. The long range modeling (but lowest skill at the timeframes concerned) seems to hint at more opportunities for cold outbreaks and snowfall in the CONUS/southern Canada during February into March. I think the big question right now concerns the degree of blocking that will develop. That really can't be forecast reliably at long timeframes (even AO+/NAO+ winters can still have one or two good episodes of blocking and if the blocking is timed with an active jet, opportunities for snowfall can exist).

For now, I still think the Great Lakes region will see near normal to somewhat above normal snowfall (around 45" in Detroit), even as temperatures are somewhat warmer than normal. The same applies for Chicago and Toronto. The Mid-Atlantic and New England regions will probably be below normal with snowfall (lower precipitation even as the winter isn't as warm as the last two), but not as bad as the last two winters. Boston will probably end its record slump where it hasn't received 4" or more daily snowfall (964 consecutive days through today). The Northern Plains/Northern Rockies probably have the best chance  in the CONUS of being colder than normal. Western Canada could be cold especially as the PDO- is likely to persist.

Not far off my overall thoughts for this area....I am REALLY interested in December only because of the history of snowy La Nina Decembers. It certainly isnt a slam dunk (there have been duds) but there is a definite correlation to above avg snowfall in December. It is the strongest snowfall correlation (+ or -) of any la nina month.

[michsnowfreak]

13 hours ago, Stormchaserchuck1 said:

The last 4 runs of GFS ensembles at 384hr (0.75 pattern correlation) have showed a decent +EPO for the 1st day of November. If we were to see a predominantly -EPO this Winter, this is when history says it would usually start to show itself. But the opposite is occurring, with at least the 1st week of November looking probably warm. 

Natural Gas has also gone down a lot in the last few days with the NG/CL-Gasoline spread the 2nd lowest on record, behind only last year at this time. 

Not sure what the EPO was, however last year we had a snowy Halloween here and a cold start to November which certainly didnt portray the winter as a whole lol.

Speaking of November, strictly from a snow perspective, I thought this was interesting. Detroit has not seen a below normal snowfall November since 2017. Going back to 2010, a total of 14 years, 10 of the 14 saw Novembers snowfall anamoly NOT correlate to the winter that followed.

[GaWx]

55 minutes ago, snowman19 said:

Done purposely. Wxbell/JB wants the all their flawed maps so they can hype a cold and snowy east coast winter year after year and feed their weenie base for subscription money. That’s the only way they are able to survive…..hyping a cold/snowy east coast and denying climate change. 99% of their paid subscribers are I-95 weenies. They are laughing all the way to the bank

 I sure hope that these flawed CFS maps are not due to intentional manipulation like you’re saying! I’ve not been assuming that. Wouldn’t that be illegal? Why would a company take that chance?

[brooklynwx99]

2 hours ago, GaWx said:

 Actually, CANSIPS has also been showing a strong -PDO.
 
 The only maps I’ve seen not showing a strong -PDO this winter are the heavily flawed WxBell CFS maps, which have on several occasions already been shown to be garbage and are far different from other versions of the same model! They were even showing a +PDO for this winter, which was getting JB excited and posting them. However, they’ve since backed down to neutral (though that’s still WAY off) as we’ve gotten closer due to the partial correction of the flawed maps. That’s why JB has recently not been as vocal about a possible +PDO this winter. However, WB CFS still show a +PDO but now not til spring (WPAC marine heatwave gone lmao) while TT CFS show no such thing. The flawed WB algorithms won’t allow the entire runs to avoid getting rid of the marine heatwave and showing a +PDO:

WB CFS for Apr 2025: WPAC marine heatwave magically gone with fake strongly BN blue/green area covering much of WPAC:

 

TT CFS for Apr 2025: WPAC marine heatwave intact and AN where WB has strong BN on the SAME model with similar base climo:

 

@donsutherland1

the WB map is a control run... it's only showing one scenario. the TT map is an average of the last 12 forecasts. they are showing fundamentally different things. this gets rehashed every time people post a WB CFS map

[mitchnick]

14 minutes ago, GaWx said:

 I sure hope that these flawed CFS maps are not due to intentional manipulation like you’re saying! I’ve not been assuming that. Wouldn’t that be illegal? Why would a company take that chance?

I always use the Cfs2 website as TT don't look right compared to it. Only problem is no 500mb anomaly maps.

https://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2_body.html

It's got daily monthly and weekly forecasts under the links under "Cfs2 Related Links." They do have 500mb anomaly maps.

[brooklynwx99]

also with 2013-14 and the PDO... not sure why this has to be stated again and again either. that year has things going for it other than just the PDO, which, by the way, isn't really congruent with that we're seeing. the PDO isn't one of the reasons why that year is being used

the orientation of the SSTs (hybrid/CP Nina), the QBO, and solar are all pretty solid matches. is it a perfect year by any means? no. do I expect it to get as cold as that year? absolutely not. does it deserve to get completely tossed aside? no... analog forecasting is about mixing a bunch of years that can bring something to the table, and that year is one of them. I can see episodes of -EPO blocking showing up, just not nearly as persistently

the extratropical Pacific could render the year useless, but it's never really ever that simple

[snowman19]

4 minutes ago, brooklynwx99 said:

also with 2013-14 and the PDO... not sure why this has to be stated again and again either. that year has things going for it other than just the PDO, which, by the way, isn't really congruent with that we're seeing. the PDO isn't one of the reasons why that year is being used

the orientation of the SSTs (hybrid/CP Nina), the QBO, and solar are all pretty solid matches. is it a perfect year by any means? no. do I expect it to get as cold as that year? absolutely not. does it deserve to get completely tossed aside? no... analog forecasting is about mixing a bunch of years that can bring something to the table, and that year is one of them. I can see episodes of -EPO blocking showing up, just not nearly as persistently

the extratropical Pacific could render the year useless, but it's never really ever that simple

The thing is, the 500mb pattern since 9/1 till now doesn’t match up at all with 2013. It’s night and day different. Apples and oranges between then and now at 500mb

[brooklynwx99]

1 minute ago, snowman19 said:

The thing is, the 500mb pattern since 9/1 till now doesn’t match up at all with 2013. It’s night and day different. Apples and oranges between then and now at 500mb

not really. this is apples and oranges? sure, there was more NAO blocking in 2013 and no weak +PNA, but the ET Pacific is very similar, which seems to be the main focus of most of the LR discussion. I would argue that it's much more important than something as mercurial as the NAO domain

[brooklynwx99]

closer look at the ET Pacific for those two years. I'd argue that it's quite difficult to get years about 10 years apart from each other to match up that well in that domain

[donsutherland1]

1 hour ago, michsnowfreak said:

Not far off my overall thoughts for this area....I am REALLY interested in December only because of the history of snowy La Nina Decembers. It certainly isnt a slam dunk (there have been duds) but there is a definite correlation to above avg snowfall in December. It is the strongest snowfall correlation (+ or -) of any la nina month.

The just-released CPC winter outlook seems to be more in line with what I'm thinking than the ECMWF seasonal forecast, particularly for the Great Lakes Region.

 

 

[George001]

18 minutes ago, snowman19 said:

The thing is, the 500mb pattern since 9/1 till now doesn’t match up at all with 2013. It’s night and day different. Apples and oranges between then and now at 500mb

The big thing with the fall pattern is it has been fairly dry for most of the US. It has also been warmer than average throughout the CONUS, with most of the warmth centered over the plains. So I plan to look to falls that have a similar temp profile and precip profile across the conus and adjust my analogs accordingly. I’m actually not sure what it will look like yet. I do want to see the 1st half of November first though.

[PhiEaglesfan712]

2 minutes ago, George001 said:

The big thing with the fall pattern is it has been fairly dry for most of the US. It has also been warmer than average throughout the CONUS, with most of the warmth centered over the plains. So I plan to look to falls that have a similar temp profile and precip profile across the conus and adjust my analogs accordingly. I’m actually not sure what it will look like yet. I do want to see the 1st half of November first though.

I can already tell you that 1998 is going to be one of the analogs. I've done that fall/winter composite ad nauseum.

[40/70 Benchmark]

1 hour ago, brooklynwx99 said:

also with 2013-14 and the PDO... not sure why this has to be stated again and again either. that year has things going for it other than just the PDO, which, by the way, isn't really congruent with that we're seeing. the PDO isn't one of the reasons why that year is being used

the orientation of the SSTs (hybrid/CP Nina), the QBO, and solar are all pretty solid matches. is it a perfect year by any means? no. do I expect it to get as cold as that year? absolutely not. does it deserve to get completely tossed aside? no... analog forecasting is about mixing a bunch of years that can bring something to the table, and that year is one of them. I can see episodes of -EPO blocking showing up, just not nearly as persistently

the extratropical Pacific could render the year useless, but it's never really ever that simple

Yes. This concept is continuously lost on people, so I have began to covey the progeression of the season using "sensible weather" analogs for each month, which is different from the DM seasonal composite....the latter is what compiles that list of years that I believe has utilty for the season in one way or another. I think this helps to distinguish which elements of each analog season are most relevent to this year.

[GaWx]

2 hours ago, brooklynwx99 said:

the WB map is a control run... it's only showing one scenario. the TT map is an average of the last 12 forecasts. they are showing fundamentally different things. this gets rehashed every time people post a WB CFS map

I realize that. But just about every WB CFS control run has a similar SSTa pattern with that large cold area that doesn’t show up on any other CFS maps anywhere and a strong moderation of the marine heatwave, both pure BS. So, an avg of 12 of them would usually be similar. The true CFS output isn’t showing anything of the sort. Thus, it’s essentially fake. For example, here are the last 5 for April:

[bluewave]

7 hours ago, 40/70 Benchmark said:

This is why the PDO is near record negative territory despite the warmth off of the California coast, which is traditonally indicative of a +PDO. It’s becoming increasingly important for forecasters to assume a wholistic approach in global analysis because the unprecedented degree of warmth around the planet is limiting how much can be gleaned from focusing on any single node or geographical area. Whereas in the past we focused on areas of warmth in our assessment of the anticipated pattern it has now becoming apparent that relativity is of the utmost importance since the planet is a sea of warmth. This is the flawed lens through which I viewed ENSO last season. I focused on the orientation of SSTs within the ENSO region when there was larger pool of greater warmth to the west. The warmth off of the CA coast this year represents a similar trap with respect to the PDO.

The ridges across the North Pacific and North Atlantic have been linking up into one continuous ridge during 4 out of the last 5 summers. So it’s no surprise the SSTs have been reaching record levels outside the traditional -PDO zones with so much subsidence and sunshine. The warm pool off of California and the strong ridge is a new feature which wasn’t there during the older -PDO era. Notice how there has been a continuous ridge and record SSTs underneath across much of the North Pacific. Same goes for the North Atlantic. The last strong -PDO in the early 1950s was defined more by the giant NP cold pool. These days it’s a record warm pool driving the -PDO. Also notice how the ridges back there were much weaker and covered a smaller area compared to the recent summers.

 

 

[PhiEaglesfan712]

1 minute ago, Jovanhumbertoandrade said:

What would a Modoki El Nino mean for hurricane season?

It's a rare type of El Niño in which unfavorable conditions are produced over the eastern Pacific instead of the Atlantic basin due to warmer sea surface temperatures farther west along the equatorial Pacific. The result would be a very deadly, destructive, and active hurricane season, like 2004.

That said, I do not see it happening. I just cannot see the PDO (which is at near record negative) anywhere near neutral or even +PDO like we had in 2004-05 to form the modoki el nino. [Remember, the last transition from -PDO to +PDO, which started in 2013, took at least a couple years to complete. Also, everyone was talking about an el nino in 2012-13, and it didn't start to form until fall 2014, and only really took off in spring 2015.] I suppose we'll still be in -PDO, and either in la nina or ENSO neutral in 2025-26.

[Stormchaserchuck1]

9 hours ago, 40/70 Benchmark said:

Was there any resistance to the notion of a -PDO this winter? I'm not trying to be an ass....I'm honestly am not sure what can be gleaned from this because everyone was already resigned to it.

It's one thing when the PDO is X value. It's another when it's accurately predicting the state of the atmosphere months in advance.  In 2013 it was not hitting in the Fall. 

The one month that the PDO doesn't have a high correlation to is December.. 

Its highest is Jan-Feb. SE ridge signal of +0.5, or 75%. 

March is just as weak as December. 

[40/70 Benchmark]

56 minutes ago, PhiEaglesfan712 said:

It's a rare type of El Niño in which unfavorable conditions are produced over the eastern Pacific instead of the Atlantic basin due to warmer sea surface temperatures farther west along the equatorial Pacific. The result would be a very deadly, destructive, and active hurricane season, like 2004.

That said, I do not see it happening. I just cannot see the PDO (which is at near record negative) anywhere near neutral or even +PDO like we had in 2004-05 to form the modoki el nino. [Remember, the last transition from -PDO to +PDO, which started in 2013, took at least a couple years to complete. Also, everyone was talking about an el nino in 2012-13, and it didn't start to form until fall 2014, and only really took off in spring 2015.] I suppose we'll still be in -PDO, and either in la nina or ENSO neutral in 2025-26.

I agree it will probably take 2-3 years to transition out of this when in fact we do...but we don't necessarily need a big +PDO to get a Modoki El Nino.

[40/70 Benchmark]

25 minutes ago, Stormchaserchuck1 said:

It's one thing when the PDO is X value. It's another when it's accurately predicting the state of the atmosphere months in advance.  In 2013 it was not hitting in the Fall. 

The one month that the PDO doesn't have a high correlation to is December.. 

Its highest is Jan-Feb. SE ridge signal of +0.5, or 75%. 

March is just as weak as December. 

Most of the periods of disconnect from the west Pac warm pool driven MC forcing has actually been in January into early February. 

[Maestrobjwa]

1 minute ago, 40/70 Benchmark said:

Most of the periods of disconnect from the west Pac warm pool driven MC forcing has actually been in January into early February. 

That warm pool still there like it has been seemingly forever? (And I never have quite understood what it is exactly)

[Stormchaserchuck1]

It looks like the CPC thinks the EPO will go negative for the Winter, or the N. Pacific ridge will go polar and extend north. I had this opinion in the Summer, but the last 1-2 months has been more of the same pattern that we have seen for the last 6 Winter's, imo. Will be interesting to see if they verify.. they usually don't go so cold as they are over the PNW and Upper Midwest for a 3-month period. This is especially interesting because the SW, US has been +7F over their all time records for a 3-week period lately. They usually smooth the overall warming signal out for a seasonal forecast, but the forecast is downright cold in the NW 1/3 of the US. 

If the NW has such a cold Winter, I don't see how we don't go extremely warm in the East, given what has happened over the last few Winters.. we had 3 days of +NAO ridging last January, and DC hit 80*. The same is happening tomorrow.. the NAO is going positive, and there is a 591dm ridge over Toronto, Canada. Little spikes are causing some extreme +departures days. 

[so_whats_happening]

3 hours ago, bluewave said:

The ridges across the North Pacific and North Atlantic have been linking up into one continuous ridge during 4 out of the last 5 summers. So it’s no surprise the SSTs have been reaching record levels outside the traditional -PDO zones with so much subsidence and sunshine. The warm pool off of California and the strong ridge is a new feature which wasn’t there during the older -PDO era. Notice how there has been a continuous ridge and record SSTs underneath across much of the North Pacific. Same goes for the North Atlantic. The last strong -PDO in the early 1950s was defined more by the giant NP cold pool. These days it’s a record warm pool driving the -PDO. Also notice how the ridges back there were much weaker and covered a smaller area compared to the recent summers.

 

 

I mean just looking at the SST patterns they look very similar in both time periods, right now we have warmer oceans so to compensate for the same -PDO signature and value we have higher anomalies than the surroundings just as you did back in the day. As for the 500mb pattern can't explain the difference but we could easily be in a constructive pattern versus a destructive pattern overall. Im sure the atmospheric warmth right now plays a role in allowing a more ridge like presence versus a trough like presence but im sure this flip flops so much it is hard to say this will be what the pattern should be.

The biggest issue I have is we have seen these marine heatwaves before this is in fact what you are pointing out right now but what is to say that a -PDO should produce this atmospheric pattern. It may be more common for a pattern to occur during these strong phases of teleconnection but it does not necessarily mean that this will always be the resulting pattern.

Im sure ill get lambasted for such a take.

[michsnowfreak]

1 hour ago, Stormchaserchuck1 said:

It looks like the CPC thinks the EPO will go negative for the Winter, or the N. Pacific ridge will go polar and extend north. I had this opinion in the Summer, but the last 1-2 months has been more of the same pattern that we have seen for the last 6 Winter's, imo. Will be interesting to see if they verify.. they usually don't go so cold as they are over the PNW and Upper Midwest for a 3-month period. This is especially interesting because the SW, US has been +7F over their all time records for a 3-week period lately. They usually smooth the overall warming signal out for a seasonal forecast, but the forecast is downright cold in the NW 1/3 of the US. 

If the NW has such a cold Winter, I don't see how we don't go extremely warm in the East, given what has happened over the last few Winters.. we had 3 days of +NAO ridging last January, and DC hit 80*. The same is happening tomorrow.. the NAO is going positive, and there is a 591dm ridge over Toronto, Canada. Little spikes are causing some extreme +departures days. 

Are you still liking above avg precip in the Lakes?

[Stormchaserchuck1]

1 hour ago, michsnowfreak said:

Are you still liking above avg precip in the Lakes?

Yeah. Possibly well above average, as the normal jet stream is south in the Winter, but a SE ridge would have storms riding up to the Great Lakes. 

You could be pretty excited by the CPC's Winter forecast, with cold dropping in not too far away, but I'm not really agreeing with them. I think they are really underestimating the potential warmth in the east, only giving 40-50% chance for above normal here.  I think this Winter will have a lot of variation/volatility.. I think we may see -WPO/-EPO periods, but they may not last more than 5-8 days. The overall trend will be warm. It's a little bit different when a Winter is wall-to-wall warm, vs very warm periods and below average periods.. You can get snow in Winter's of variance.. I had a 20" storm in 99-00. If we have a +NAO jet stream like I think, the timing with a -EPO period could give you a nice snowstorm(s).  It's not all ridgy everywhere like the last few years, so northern areas should do ok I think.