2024-2025 La Nina

[Stormchaserchuck1]

This looks like a Strong El Nino December

Very +AAM. It seems that those AAM graphs that people have been positing has some value, as this pattern only showed up in the last day or two. 

[Stormchaserchuck1]

3 hours ago, snowman19 said:

I am doubtful of a major SSWE. Not to minimize the study @GaWx found, which was compelling, but just based on the data @Stormchaserchuck1 posted, we are very closely (so far) following the Niña/+QBO/high solar years that featured a very cold stratosphere. Secondly, this year’s +QBO event isn’t just strong. It’s approaching record strong numbers

I just wouldn't expect a major Stratosphere warming.  Also the November 50mb QBO is the highest ever since 1979, at +12.17 (#2 is +10.75). 

[leo2000]

5 minutes ago, Stormchaserchuck1 said:

This looks like a Strong El Nino December

Very +AAM. It seems that those AAM graphs that people have been positing has some value, as this pattern only showed up in the last day or two. 

No pacific ridge -EPO in that graph though. I see blue low heights near Alaska. 

[Stormchaserchuck1]

1 minute ago, leo2000 said:

No pacific ridge -EPO in that graph though. I see blue low heights near Alaska. 

At 500mb, +AAM favors a trough in the Gulf of Alaska and ridge south of Greenland. Not much of the EPO correlates with AAM, maybe it favors it being slightly positive. 

[GaWx]

New Euro Weeklies: stronger SPV (NN) vs yesterday’s slightly weak SPV; any hints of late Dec warming are reduced vs yesterday’s run: climo favors any possible major SSW this winter to be later than this, regardless:

 

 Fwiw, Christmas week has cooled on the new Euro Weeklies with mainly NN E US (no torch):

[mitchnick]

6 minutes ago, GaWx said:

New Euro Weeklies: stronger SPV (NN) vs yesterday’s slightly weak SPV; any hints of late Dec warming are reduced vs yesterday’s run:

 

 Fwiw, Christmas week has cooled on the new Euro Weeklies with mainly NN E US (no torch):

Surprise, surprise! Only 1 warm week on today's weeklies. January really looking like the Canadian January forecast. Of course, that's as of today. It'll change again tomorrow, hopefully colder! 

[GaWx]

7 minutes ago, mitchnick said:

Surprise, surprise! Only 1 warm week on today's weeklies. January really looking like the Canadian January forecast. Of course, that's as of today. It'll change again tomorrow, hopefully colder! 

The one thing I hope doesn’t verify is the SE ridge of the final week, something a La Nina tends to favor and why I like El Niño much more: I want the +PNA to return/W ridge too far W!

[MJO812]

Euro weeklies matches this

[michsnowfreak]

14 minutes ago, mitchnick said:

Surprise, surprise! Only 1 warm week on today's weeklies. January really looking like the Canadian January forecast. Of course, that's as of today. It'll change again tomorrow, hopefully colder! 

Yes, and they really get cold week 6. Usually you dont see such strong departures (warm or cold) in the later weeks from the main weeklies (the control run is another story).

[GaWx]

51 minutes ago, michsnowfreak said:

Yes, and they really get cold week 6. Usually you dont see such strong departures (warm or cold) in the later weeks from the main weeklies (the control run is another story).

 Just to clarify for the readers, the last week, indeed, has an impressive cold area but it’s bottled up in SW Canada, N Rockies/Plains, and upper Midwest (Ninalike) with not much of a push SE from week 5. The SE ridge is then keeping the cold from the E US and making it mild in the deep SE, a common pattern during La Niña. I’ve seen many cases like this that only allow any cold to slowly seep SE and never cool the SE/Mid Atlantic that much. From the E US perspective, these situations make this “wasted cold”. Long way to go and it will change many times for better or worse, but that does fit Niña and warm MC climo well:

 

Here’s the week prior (week 5):

 

@bluewave

[mitchnick]

23 minutes ago, GaWx said:

 Just to clarify for the readers, the last week, indeed, has an impressive cold area but it’s bottled up in SW Canada, N Rockies/Plains, and upper Midwest (Ninalike) with not much of a push SE from week 5. The SE ridge is then keeping the cold from the E US and making it mild in the deep SE, a common pattern during La Niña. I’ve seen many cases like this that only allow any cold to slowly seep SE and never cool the SE/Mid Atlantic that much. From the E US perspective, these situations make this “wasted cold”. Long way to go and it will change many times for better or worse, but that does fit Niña and warm MC climo well:

 

Here’s the week prior (week 5):

Good points Larry, but with michsnowfreak being in...Michigan, his excitement is justified imho. I know I'd be right there with him if I was in Michigan. 

[GaWx]

27 minutes ago, mitchnick said:

Good points Larry, but with michsnowfreak being in...Michigan, his excitement is justified imho. I know I'd be right there with him if I was in Michigan. 

Thanks. Based on this run, I’d be most excited from a cold perspective if I were in, say, Minneapolis. Also, as Chris knows well, the models often are cold biased in the E US due largely to the warm MC. So, what often happens if that they verify warmer in the E US vs what they show as the SE ridge verifies more strongly (i.e., leading to cold bias of models)

[brooklynwx99]

is the La Niña in the room with us?

[MANDA]

13 minutes ago, brooklynwx99 said:

is the La Niña in the room with us?

In the room?  Looks more like it has taken over the house.

Ugly.

[Terpeast]

20 minutes ago, MANDA said:

In the room?  Looks more like it has taken over the house.

Ugly.

I know you were joking, but that strong aleutian low is definitely not la nina. Something else is driving this. 

[MANDA]

19 minutes ago, Terpeast said:

I know you were joking, but that strong aleutian low is definitely not la nina. Something else is driving this. 

yes, was really just joking about how ugly it looked. 

[brooklynwx99]

13 minutes ago, MANDA said:

yes, was really just joking about how ugly it looked. 

that trough is going to retrograde and likely pop a nice +PNA. it’s transient

[MJO812]

1 hour ago, brooklynwx99 said:

that trough is going to retrograde and likely pop a nice +PNA. it’s transient

Yep. Pattern looks alot better after Christmas ..

[brooklynwx99]

@snowman19 seems like you don’t think the trough will retrograde? if this truly is acting like a Niña we should see the jet relax and the trough will retrograde as a result

[bluewave]

11 hours ago, Terpeast said:

I know you were joking, but that strong aleutian low is definitely not la nina. Something else is driving this. 

Maybe that very strong Aleutian Low which both the EPS and GEFS have is a delayed response to the quick Nino 1+2 warming and record EPAC WWB back in late November. Notice how many of the CPC day 8-14 analogs are El Niño Decembers. That is a very strong El Niño look.

 

 

[EasternLI]

8 hours ago, brooklynwx99 said:

@snowman19 seems like you don’t think the trough will retrograde? if this truly is acting like a Niña we should see the jet relax and the trough will retrograde as a result

Seems like the events of November have left the atmosphere in a more Niño-like state. If the MJO is effective in the Pacific. Probably another WWB and +EAMT in January?

 

https://x.com/Met4CastUK/status/1864797137227387090?t=K3C8XrFImAvNwHt5_u21Mw&s=19

[Terpeast]

14 minutes ago, bluewave said:

Maybe that very strong Aleutian Low which both the EPS and GEFS have is a delayed response to the quick Nino 1+2 warming and record EPAC WWB back in late November. Notice how many of the CPC day 8-14 analogs are El Niño Decembers. That is a very strong El Niño look.

 

 

That would be a very long delay if 1.2 was behind this. It could be more due to the recent +AAM spike after Thanksgiving, even though it has waned a bit. 

[bluewave]

11 minutes ago, Terpeast said:

That would be a very long delay if 1.2 was behind this. 

Several of the MJO composites which can have lags for where the forcing has been recently also have a very strong Aleutian Low. Especially given how strong the Aleutian Ridge was recently would take longer to reverse. So we could be seeing an odd mix of competing influences that we normally don’t see in December together. I guess the bottom line is that both the MJO and Nino 1+2 composites are warm this time of year.

[jbenedet]

MJO 5/6 in December points to a split flow regime where there are significant negative temp anomalies in the western CONUS. This implies “troughiness” out west; but you don’t see this translate to significant warmth in the east.  So ridges in the east tend to be dampened to the point that non-arctic based Canadian cold can slip in to the northern US periodically and the southeast gets maritime pacific which isn’t warm for their December climate…

And thats what I’m seeing in the modeling consensus. No real mystery to the upcoming pattern in terms of the MJO forecast.

Now why are we in a potent phase 5/6 in a December La Niña is the more important question… 

 

[GaWx]

 The 1st week of Dec at KSAV has a shot at ending up the 6th coldest since 1874! Only colder for sure assuming I didn’t miss others: 2000, 1910, 1896, 1886, 1876. 1944 was very close. 

 Low today 25, coldest of season so far.

Edit: 2024 ends up tied with 1944 for 6th coldest 1st week of Dec since 1874.

 When taking into account warming climo, 2024 looks like it is the 3rd coldest 1st week in Dec behind only #1 1876 and #2 2000!

[GaWx]

I feel this is bordering on hype as I’m seeing no evidence of above climo chance at major SSW later in the month at least as of now though I’ll continue to follow:

Despite what he says:

 

 So, why is he saying “major stratwarm to develop later in the month”? Major stratwarm requires 10 mb wind reversal. Euro says 2% chance and GEFS says 0%.

 

[GaWx]

Taking CFS extended with a huge grain so fwiw:

[MJO812]

Just now, GaWx said:

Taking CFS extended with a huge grain so fwiw:

This is when the MJO will be in the favorable phases so this has merit.

[mitchnick]

44 minutes ago, GaWx said:

I feel this is bordering on hype as I’m seeing no evidence of above climo chance at major SSW later in the month at least as of now though I’ll continue to follow:

Despite what he says:

 

 So, why is he saying “major stratwarm to develop later in the month”? Major stratwarm requires 10 mb wind reversal. Euro says 2% chance and GEFS says 0%.

 

Larry, Tip posted this yesterday in the NE forum, which "may" be related to it, idk as I  really didn't bother to look into it.
     
https://www.americanwx.com/bb/topic/61325-december-2024-best-look-to-an-early-december-pattern-in-many-a-year/?do=findComment&comment=7489944

[snowman19]

1 hour ago, GaWx said:

I feel this is bordering on hype as I’m seeing no evidence of above climo chance at major SSW later in the month at least as of now though I’ll continue to follow:

Despite what he says:

 

 So, why is he saying “major stratwarm to develop later in the month”? Major stratwarm requires 10 mb wind reversal. Euro says 2% chance and GEFS says 0%.

 

JB rendered himself completely irrelevant years ago. The guy is delusional and willing to spread false info and lies to those who don’t know any better just for money, likes, retweets and follows. Only the hard core weenies take him seriously anymore. He’s nothing but a shit stain on the meteorological profession