2024-2025 La Nina

[Terpeast]

2 minutes ago, GaWx said:

Note that the spread of members’ amplitude on the GEFS’ MJO forecast is quite wide:

True, good point. Looks really noisy. In that situation we’re probably better off looking at the hollmover charts, but I’m skeptical of a standing wave longer than 1-2 weeks because even strong tropical convection is almost always self-limiting. It will either weaken or move. 

[snowman19]

6 hours ago, mitchnick said:

Not that I disagree with the 2 week warm period, but this trough/cold later this week is trending noticeably colder than just 2 days ago. Imby, it's looking colder than the cold this past week. But that will just be glossed over by most.

 

P.s. That's a cold run on the 6z Gfs fwiw

It’s been cold and it’s going to get cold later this week. No doubt. You’d have to be a fool not to acknowledge that. Could very well be that we are seeing a classic “front-end loaded” La Niña. If that’s indeed the case, just lends even more confidence that the pattern goes canonical La Niña mid-late January and especially February and March since we seem to be following a classic progression 

[vegan_edible]

1 minute ago, snowman19 said:

It’s been cold and it’s going to get cold later this week. No doubt. You’d have to be a fool not to acknowledge that. Could very well be that we are seeing a classic “front-end loaded” La Niña. If that’s indeed the case, just lends even more confidence that the pattern goes canonical La Niña mid-late January and especially February and March since we seem to be following a classic progression 

if we (nyc metro/EC in general) get some good rounds of snow between now and mid february i'll be a happy camper. once march comes around i want blowtorch high pressure sunny 68 degrees everyday... 
so in this instance i hope you're correct hahaha

[mitchnick]

4 minutes ago, snowman19 said:

It’s been cold and it’s going to get cold later this week. No doubt. You’d have to be a fool not to acknowledge that. Could very well be that we are seeing a classic “front-end loaded” La Niña. If that’s indeed the case, just lends even more confidence that the pattern goes canonical La Niña mid-late January and especially February and March since we seem to be following a classic progression 

Except for Raindance when he was hinting at the possibility before he exited, no forecaster or model suggested we'd see anything other than a torch this month. It may end AN imby and it may not. But I'm with Terpeast that there are more surprises ahead, and imho we may just want to throw out some of the old ways of thinking this winter because it's clear that nobody really knows how it's going to turn out. The only thing positive is that if anyone is worrying about a busted forecast, you'll likely have plenty of company. That said, I  really only care about getting snow imby so despite a cold or warm winter, if it's another BN snowfall, it'll just go down as 1 more fail.

[GaWx]

11 minutes ago, mitchnick said:

Except for Raindance when he was hinting at the possibility before he exited, no forecaster or model suggested we'd see anything other than a torch this month. It may end AN imby and it may not. But I'm with Terpeast that there are more surprises ahead, and imho we may just want to throw out some of the old ways of thinking this winter because it's clear that nobody really knows how it's going to turn out. The only thing positive is that if anyone is worrying about a busted forecast, you'll likely have plenty of company. That said, I  really only care about getting snow imby so despite a cold or warm winter, if it's another BN snowfall, it'll just go down as 1 more fail.

 Regarding the bolded, is it ever really clear in advance how it’s going to turn out? I don’t recall a winter here without widely varying feelings. If it were clear, these forecasting threads would be pretty boring. Nobody ever knows for sure. It is the uncertainty that makes for great forecasting discussions. Long range forecasting is a crap-shoot in that way and it really takes high skills to have a good chance to do well consistently. Even the very best models like the Euro are often fooled just a couple of weeks out!

[binbisso]

Big changes on the gefs for mid-late December. Went from this 

To this. I wonder if this is reflecting the weaker gfs mjo

[roardog]

1 hour ago, snowman19 said:

@Bluewave @GaWx Here is a real good illustration of my point. The Niña standing wave is clear as day. The entire atmospheric and oceanic circulation is classic La Niña. Very good read here and why I seriously doubt the MJO signal ever makes it to or across the dateline:

 

 

 

 

I don't know. I mean if the atmosphere is classic Nina, wouldn't the global pattern reflect that? It looks nothing like Nina now and if the ensembles are correct with the Aleutian low in the medium range, that's about as opposite of Nina as you can get. 

[George001]

33 minutes ago, snowman19 said:

It’s been cold and it’s going to get cold later this week. No doubt. You’d have to be a fool not to acknowledge that. Could very well be that we are seeing a classic “front-end loaded” La Niña. If that’s indeed the case, just lends even more confidence that the pattern goes canonical La Niña mid-late January and especially February and March since we seem to be following a classic progression 

It’s not a La Niña, it’s cold neutral. Even other non ONI indices indicate a weak event at best, so I would not expect ENSO to be a big driver this year. I actually have the opposite view, I’m expecting a lot of western troughing the rest of Dec well into Jan. The cold snap only looks to be a 7-10 day event, with the warmth lasting 2-3 weeks. If guidance is right, we would be in a warm dominated pattern. Im more optimistic about the second half of winter due to the weakening -PDO. It will still be negative, but not the degree it is now. Also, I’m skeptical of the guidance rapidly weakening the polar vortex, I’m thinking that is both overdone and it’s being rushed. 

[GaWx]

3 minutes ago, George001 said:

It’s not a La Niña, it’s cold neutral. Even other non ONI indices indicate a weak event at best, so I would not expect ENSO to be a big driver this year. I actually have the opposite view, I’m expecting a lot of western troughing the rest of Dec well into Jan. The cold snap only looks to be a 7-10 day event, with the warmth lasting 2-3 weeks. If guidance is right, we would be in a warm dominated pattern. Im more optimistic about the second half of winter due to the weakening -PDO. Also, I’m skeptical of the guidance rapidly weakening the polar vortex, I’m thinking that is both overdone and it’s being rushed. 

In terms of mean zonal 10 mb winds at 60N, the gold standard for measuring the weakness of the SPV, I’m not currently seeing a rapid weakening on either the Euro Weeklies or the extended GEFS.

[snowman19]

40 minutes ago, roardog said:

I don't know. I mean if the atmosphere is classic Nina, wouldn't the global pattern reflect that? It looks nothing like Nina now and if the ensembles are correct with the Aleutian low in the medium range, that's about as opposite of Nina as you can get. 

@mitchnick It goes beyond ONI. It’s no longer a good ENSO indicator due to all the AGW background warming. It’s all just getting washed out. Case in point, look at what I just posted, it’s all indicative of a healthy La Niña event not La Nada despite the current ONI. 

It is absolutely a classic La Niña circulation. Atmospherically and oceanically: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Maestrobjwa]

17 minutes ago, George001 said:

It’s not a La Niña, it’s cold neutral. Even other non ONI indices indicate a weak event at best, so I would not expect ENSO to be a big driver this year. I actually have the opposite view, I’m expecting a lot of western troughing the rest of Dec well into Jan. The cold snap only looks to be a 7-10 day event, with the warmth lasting 2-3 weeks. If guidance is right, we would be in a warm dominated pattern. Im more optimistic about the second half of winter due to the weakening -PDO. It will still be negative, but not the degree it is now. Also, I’m skeptical of the guidance rapidly weakening the polar vortex, I’m thinking that is both overdone and it’s being rushed. 

PAUSE...So you're telling me the relentless -PDO of the last 8-9 is indeed finally weakening? 

[mitchnick]

33 minutes ago, GaWx said:

 Regarding the bolded, is it ever really clear in advance how it’s going to turn out? I don’t recall a winter here without widely varying feelings. If it were clear, these forecasting threads would be pretty boring. Nobody ever knows for sure. It is the uncertainty that makes for great forecasting discussions. Long range forecasting is a crap-shoot in that way and it really takes high skills to have a good chance to do well consistently. Even the very best models like the Euro are often fooled just a couple of weeks out!

 

35 minutes ago, GaWx said:

 Regarding the bolded, is it ever really clear in advance how it’s going to turn out? I don’t recall a winter here without widely varying feelings. If it were clear, these forecasting threads would be pretty boring. Nobody ever knows for sure. It is the uncertainty that makes for great forecasting discussions. Long range forecasting is a crap-shoot in that way and it really takes high skills to have a good chance to do well consistently. Even the very best models like the Euro are often fooled just a couple of weeks out!

To answer your question, yes, it was this year...or so it seemed!

My point was more that this year "seemed" to have all the canonical earmarks of a warm Niña, considering recent history and seasonal model agreement. It may still end up that way, but considering how it has started and what MR guidance is showing, it's going to be awful ballzy to stick with an AN Conus for the rest of the winter imho.

[GaWx]

 Note the animation below in this TN Valley subforum post. This is the kind of thing that has been common over the last 8 years (things backing up NW as forecasting time decreases probably largely related to the MC warm pool). This is an illustration of what causes the cold bias of most models in the E US. I hope this isn’t a sign of things to come the rest of this winter although I fear the realistic possibility:

 

@bluewaverefers to this tendency often

 

[bluewave]

2 hours ago, snowman19 said:

@Bluewave @GaWx Here is a real good illustration of my point. The Niña standing wave is clear as day. The entire atmospheric and oceanic circulation is classic La Niña. Very good read here and why I seriously doubt the MJO signal ever makes it to or across the dateline:

 

 

 

 

While we can definitely see the La Niña background influence, that strong Aleutian Low showing up for mid-December is an El Niño feature with many Nino years in the current CPC forecast D11 composite.

 

20061209….El Nino
19941219….El Nino 
19861222..El Nino
19661214..cold neutral
20051226….La Nina
20061221….El Nino 
19861227..El Nino
19721222….El Nimo 
20061226….El Nino 
20021211..El Nino

[mitchnick]

32 minutes ago, snowman19 said:

It is absolutely a classic La Niña circulation. Atmospherically and oceanically:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Snowman, I'm not disagreeing that right now looks like a Niña, but the majority of Niñas peak by the end of December and we haven't had one month of a -.5C in Enso 3.4  So unless you have a really odd Niña push, you're going to lose the Niña background before winter's end; and with a weak state, how much of a lag will hold over, idk. Plus, I can't help but believe that the cold is not at least, in part, due to a La Nada atmosphere. 

 

[GaWx]

1 hour ago, binbisso said:

Big changes on the gefs for mid-late December. Went from this 

To this. I wonder if this is reflecting the weaker gfs mjo

You can add the 12Z EPS to the 12Z GEFS that is cooler in the E US 12/21-3. Along with the 12/11-4 cooldown: if this keeps up the E US is going to have a hard time not ending up with a pretty solidly BN Dec as a whole.

[bluewave]

2 hours ago, mitchnick said:

Except for Raindance when he was hinting at the possibility before he exited, no forecaster or model suggested we'd see anything other than a torch this month. It may end AN imby and it may not. But I'm with Terpeast that there are more surprises ahead, and imho we may just want to throw out some of the old ways of thinking this winter because it's clear that nobody really knows how it's going to turn out. The only thing positive is that if anyone is worrying about a busted forecast, you'll likely have plenty of company. That said, I  really only care about getting snow imby so despite a cold or warm winter, if it's another BN snowfall, it'll just go down as 1 more fail.

I was discussing the possibility of a La Niña mismatch for December back in this thread during October. Past instances of this occurrence featured +PNA patterns during La Niña Decembers. But there were other factors which I noted may not be in full agreement with the past years. One of those is that the La Niña 3.4 STS are much warmer than last mismatch Decembers. So we were able to get that +SOI spike and the potential strong Aleutian low by mid-month.

But as I have been noting in this thread, the Pacific Jet is much faster than those mismatch years. This has resulted in the warmer storm track for the East Coast last week while the Great Lakes cashed in. Now we see another warmer track coming up for this week along the East Coast as the Southeast Ridge developed in the shorter range modeling.

The fact that the models have been underestimating the Pacific Jet beyond a week out doesn’t boost our confidence that todays solutions for a trough returning in the week 2 period near the East is going to have any staying power. Since the flow is so fast that the ridge axis may eventually shift east again in later runs should the heights falls near Alaska prove stronger than forecast with the potential Aleutian low.  

Whatever happens later this month it will prove to be an interesting contrast in competing influences which we have rarely seen during past Decembers.

[GaWx]

 The new Euro weeklies means are similar to recent days with NN temps in the E US in early to mid Jan when averaged out. So, neither a strong warm signal nor a strong cold signal as of yet. It of course may mean the bulk of the E US ends up averaging out pretty close to normal from a mix of warm and cold periods. Or it could be that we are still way too far out for a clearcut signal (warm or cold) to emerge that perhaps will later reveal itself. 
 
 With the warmer globe and few areas showing BN vs numerous areas showing AN, I’m quite content to see the NN dominance persist. For illustration, look at these two weeks of global views of 2m temps and note that the NN in much of the US and Canada is actually easily the largest non-AN land area in the N Hem:

Week 5 (1/6-12):

 

Week 6 (1/13-19):

 

[mitchnick]

20 minutes ago, bluewave said:

I was discussing the possibility of a La Niña mismatch for December back in this thread during October. Past instances of this occurrence featured +PNA patterns during La Niña Decembers. But there were other factors which I noted may not be in full agreement with the past years. One of those is that the La Niña 3.4 STS are much warmer than last mismatch Decembers. So we were able to get that +SOI spike and the potential strong Aleutian low by mid-month.

But as I have been noting in this thread, the Pacific Jet is much faster than those mismatch years. This has resulted in the warmer storm track for the East Coast last week while the Great Lakes cashed in. Now we see another warmer track coming up for this week along the East Coast as the Southeast Ridge developed in the shorter range modeling.

The fact that the models have been underestimating the Pacific Jet beyond a week out doesn’t boost our confidence that todays solutions for a trough returning in the week 2 period near the East is going to have any staying power. Since the flow is so fast that the ridge axis may eventually shift east again in later runs should the heights falls near Alaska prove stronger than forecast with the strong Aleutian low.  

Whatever happens later this month  it will prove to be an interesting contrast in competing influences when we seldom have seen in past Decembers.

One thing I've noticed looking at this SSTA map is the recent cooling in the warm pool. Now, idk if this is more accurate than Oisst or Coral Reefs, but all 3 show cooling. Certainly, the map at my link seems more aggressive with temps getting a whole lot closer to normal. Anyway, it's just another piece that makes wonder if that cooling is weakening the extent of the Phases 4-5-6 effects on the Conus. Idk, just wondering. 

https://psl.noaa.gov/map/clim/sst.anom.anim.week.html

Edit: Forgot to mention cooling IO too.

[Wow]

SST trend last 7 days to show that cooling (and warming to the east).  Certainly taking the punch out of the -PDO a bit.

[Terpeast]

1 hour ago, mitchnick said:

One thing I've noticed looking at this SSTA map is the recent cooling in the warm pool. Now, idk if this is more accurate than Oisst or Coral Reefs, but all 3 show cooling. Certainly, the map at my link seems more aggressive with temps getting a whole lot closer to normal. Anyway, it's just another piece that makes wonder if that cooling is weakening the extent of the Phases 4-5-6 effects on the Conus. Idk, just wondering. 

https://psl.noaa.gov/map/clim/sst.anom.anim.week.html

Edit: Forgot to mention cooling IO too.

Probably some temporary cooling in the warm pool due to ongoing convection in that area 

[Maestrobjwa]

43 minutes ago, Terpeast said:

Probably some temporary cooling in the warm pool due to ongoing convection in that area 

Darn...I'd wish it was more than temporary (I think we all do, lol) Been hearing warm pool everyday for 8 years, smh Is it a cyclical thing?

[Terpeast]

13 minutes ago, Maestrobjwa said:

Darn...I'd wish it was more than temporary (I think we all do, lol) Been hearing warm pool everyday for 8 years, smh Is it a cyclical thing?

I think those 30+ ssts run deep, but even temporary sfc cooling will open some windows where MC forcing isn’t dominating everything

[GaWx]

 The natural gas (NG) mkt opened this evening up higher a whopping 6.5% vs the Fri afternoon close. During winter NG opening on Sun evening up that sharply the vast majority of the time means the next couple of weeks look significantly colder in the E US vs how it looked on Fri afternoon on the EPS/GEFS, which we’ve already been discussing. From a few minutes ago by Mike, a Midwest pro met. who follows this market closely:

“The ridge/west-trough east couplet mentioned yesterday has amplified a bit but the biggest deal is more cross polar flow into Canada from Siberia on the last run which introduces a MUCH cold source region for the cold when cold fronts come south from Canada.

The NWS week 2 products were still VERY bearish/mild but the market knows better. 

When was the last time you saw a huge gap higher in December with a forecast like this?

Regardless, there is a great deal of uncertainty and model runs are likely to change a great deal for the previous runs.”

[40/70 Benchmark]

10 hours ago, mitchnick said:

Except for Raindance when he was hinting at the possibility before he exited, no forecaster or model suggested we'd see anything other than a torch this month. It may end AN imby and it may not. But I'm with Terpeast that there are more surprises ahead, and imho we may just want to throw out some of the old ways of thinking this winter because it's clear that nobody really knows how it's going to turn out. The only thing positive is that if anyone is worrying about a busted forecast, you'll likely have plenty of company. That said, I  really only care about getting snow imby so despite a cold or warm winter, if it's another BN snowfall, it'll just go down as 1 more fail.

I said the month would start cold.

[40/70 Benchmark]

I'm not sure why La Nina has to automatically mean relentless blowtorch from latter January through March...I don't think that will be the case.

[mitchnick]

11 hours ago, Terpeast said:

Probably some temporary cooling in the warm pool due to ongoing convection in that area 

You may be right, but I can't recall this kind of cooling over such a large area of the warm pool, from the far western Indian Ocean to Enso 4. And would you expect this kind of cooling with just convection? Idk, just seems like maybe there's more to it. Time will tell I guess.

[roardog]

51 minutes ago, mitchnick said:

You may be right, but I can't recall this kind of cooling over such a large area of the warm pool, from the far western Indian Ocean to Enso 4. And would you expect this kind of cooling with just convection? Idk, just seems like maybe there's more to it. Time will tell I guess.

There’s actually been a lot of cooling globally for whatever reason. The global anomalies are the lowest they’ve been in a long time. 

[Terpeast]

2 hours ago, mitchnick said:

You may be right, but I can't recall this kind of cooling over such a large area of the warm pool, from the far western Indian Ocean to Enso 4. And would you expect this kind of cooling with just convection? Idk, just seems like maybe there's more to it. Time will tell I guess.

Point taken. I’m actually glad to see this.

[donsutherland1]

7 hours ago, 40/70 Benchmark said:

I said the month would start cold.

Yes. I also, felt odds leaned cold in the East. From 11/24 in this thread: "Therefore, the odds are now tilted toward a cooler than normal December in the eastern third of the U.S. including such cities as Philadelphia, New York City, Buffalo, Chicago, Detroit, and Indianapolis, among others. Toronto could also wind up colder than normal."