2024-2025 La Nina

[michsnowfreak]

27 minutes ago, GaWx said:

Note the change for 12/2-8 on the Euro Weeklies in just 4 days:

11/17 run:

 

11/21 run: 

I was just coming to post....weeklies continue to get colder.

[snowman19]

7 hours ago, bluewave said:

The thing to watch is where the storm track sets up. While the models ave been correcting stronger with the ridge over the Bering Sea into the first week of December, they still have a robust MJO wave running through 4-6. So even if it’s not the dominant factor it can still influence the storm tracks. If it’s strong enough the lows could run close to or just inland from I-95. Then the cold we see on the week 2 means could come in behind any lows rather than in front of them. If the storm tracks are still too warm for the coast, then will know the MJO is still exerting some influence. Should the storm tracks slide east then we’ll know the block near Alaska won out. It will be interesting to see how things go.

If we do in fact see a strong MJO pass through 4-5-6 in December as is being projected and there is no semblance of a typical phase response, then it will be a really huge clue that a different forcing mechanism is trumping it. Agree with that. As far as whether we see a very weak Niña or cold-neutral, there have been cases of cold-neutrals in November that ended up being Nina’s by the New Year. Do I think it’s likely? Probably not, but that said, the models are predicting a pretty healthy trade wind burst in 3.4 next month:

 

 

 

 

[snowman19]

1 hour ago, Stormchaserchuck1 said:

This is because of the constant -WPO being forecasted, through Day 16.  Beware though, 2022 started off like this.  2013 did have the pattern change from -PDO in Sept-Oct as a -WPO pattern. 

This is the +NAO/-EPO correlation I have been talking so much about, as is a default pattern right now. I was saying in the Summer that I would actually prefer +NAO in the Wintertime because of this correlation. 

That’s the issue with 2013. 1st, the PDO wasn’t starting as a record breaking -3.5 in October like this year and 2nd, the PDO started weakening by the beginning of September, 2013. This -PDO started weakening just after the beginning of November. 2013 had almost a 3 month head start on us and it wasn’t starting as a record negative event. Even though this PDO has weakened, it’s still strongly negative, in actual numbers and appearance 

[George001]

35 minutes ago, snowman19 said:

That’s the issue with 2013. 1st, the PDO wasn’t starting as a record breaking -3.5 in October like this year and 2nd, the PDO started weakening by the beginning of September, 2013. This -PDO started weakening just after the beginning of November. 2013 had almost a 3 month head start on us and it wasn’t starting as a record negative event. Even though this PDO has weakened, it’s still strongly negative, in actual numbers and appearance 

12-13 (my #1 analog) had an earlier peak, but the -PDO peaked at -3 in September and was solidly in the moderate to strongly negative range throughout the winter. The timing is a bit off but I still would consider that to be the best match for PDO. 08-09 is decent too, but the PDO was more stable, hovered just above -2 and that continued into the winter. I agree with your general point though, although the -PDO has weakened a lot historically -2 PDO Novembers lead to moderate to strongly negative PDO winters. I considered using 92-93 and 93-94 as analogs because I like the solar match, but decided to eliminate them as potential analogs after looking at the PDO progression (both years were +PDO). 

[George001]

Although I prefer 12-13 and 08-09 for the PDO specifically, in my opinion 13-14 is still a very strong analog. Great ENSO match (cold neutral), still a -PDO winter (like this will be), above average ACE, great polar match, etc. 

[George001]

1 hour ago, snowman19 said:

If we do in fact see a strong MJO pass through 4-5-6 in December as is being projected and there is no semblance of a typical phase response, then it will be a really huge clue that a different forcing mechanism is trumping it. Agree with that. As far as whether we see a very weak Niña or cold-neutral, there have been cases of cold-neutrals in November that ended up being Nina’s by the New Year. Do I think it’s likely? Probably not, but that said, the models are predicting a pretty healthy trade wind burst in 3.4 next month:

 

 

 

 

I like this tweet because it illustrates both the expected paths this winter can take (13-14, 01-02, 08-09 are all good to great analogs), and an unlikely but possible wrinkle. I do not think it will happen based on the latest guidance and current background state, but 92-93 came off a strong El Niño, was cold neutral in November and then ENSO warmed back up to warm neutral in winter. There isn’t enough to consider it a viable analog right now, but I’m keeping an eye on it as a “what could go wrong” thing. 

[PhiEaglesfan712]

18 minutes ago, George001 said:

Great ENSO match (cold neutral), still a -PDO winter (like this will be), above average ACE, great polar match, etc. 

This is in regards to 12-13, not 13-14, right? Because 2012 was an active hurricane season, 2013 not so much.

[George001]

3 minutes ago, PhiEaglesfan712 said:

This is in regards to 12-13, not 13-14, right? Because 2012 was an active hurricane season, 2013 not so much.

Yeah, my mistake. 13-14 had an extremely low ACE, it was below 50. 12-13 was the more active one with hurricane Sandy. 

[Stormchaserchuck1]

9 hours ago, snowman19 said:

That’s the issue with 2013. 1st, the PDO wasn’t starting as a record breaking -3.5 in October like this year and 2nd, the PDO started weakening by the beginning of September, 2013. This -PDO started weakening just after the beginning of November. 2013 had almost a 3 month head start on us and it wasn’t starting as a record negative event. Even though this PDO has weakened, it’s still strongly negative, in actual numbers and appearance 

2013 is about the only cold analog we have going lately, so I was just making a reference how the strong -PDO that year got weathered by a transition to -WPO in Sept through December. We had a warm Fall pattern this year and the PDO is still super negative, so that may hold weight going further into the Winter, but I do like this Pacific pattern for the next 15 days. 

[mitchnick]

From MA forum link

https://x.com/webberweather/status/1859834206731514183?ref_src=twsrc^tfw|twcamp^tweetembed|twterm^1859834206731514183|twgr^11980a2b1ad670b9969d1980f82fb5188548f3a7|twcon^s1_&ref_url=https%3A%2F%2Fwww.americanwx.com%2Fbb%2Findex.php%3Fapp%3Dcoremodule%3Dsystemcontroller%3Dembedurl%3Dhttps%3A%2F%2Ftwitter.com%2Fwebberweather%2Fstatus%2F1859834206731514183

[mitchnick]

Looks like Euro weekly control caved for December. 

[bluewave]

13 hours ago, snowman19 said:

If we do in fact see a strong MJO pass through 4-5-6 in December as is being projected and there is no semblance of a typical phase response, then it will be a really huge clue that a different forcing mechanism is trumping it. Agree with that. As far as whether we see a very weak Niña or cold-neutral, there have been cases of cold-neutrals in November that ended up being Nina’s by the New Year. Do I think it’s likely? Probably not, but that said, the models are predicting a pretty healthy trade wind burst in 3.4 next month:

 

 

 

 

It’s looking more like we some type of mismatch pattern at least for the first 2 weeks of December where the entire Pacific pattern goes in the opposite direction of La Niña due to the recent +AAM spike and Nino 1+2 warming. 

November 5th Euro forecast for December with a stock La Niña -PDO composite 

 

New run more of a mismatch pattern which I discussed back in October with the MJO following highly amplified October 2020, 2017 pattern and less influence in December

 

[michsnowfreak]

4 hours ago, Stormchaserchuck1 said:

2013 is about the only cold analog we have going lately, so I was just making a reference how the strong -PDO that year got weathered by a transition to -WPO in Sept through December. We had a warm Fall pattern this year and the PDO is still super negative, so that may hold weight going further into the Winter, but I do like this Pacific pattern for the next 15 days. 

2013 wasn't just a cold winter, it was a brutally cold winter. Combined with the heavy snow it was historic here. That's why when I see all the main analogs constantly mentioned here, even though some of them are respectable winters and not all mild, 2013-14 sticks out like a beautifully sore thumb.

[bluewave]

I recently pointed out how unusual that WWB was in the EPAC was. Thanks to Anthony for pointing out how anomalous it was. Strongest November WWB since 97-98 super El Niño at 120W. This extreme event is part of why the atmosphere has shifted to such a strong +AAM and more Nino-like pattern. 
 

https://bsky.app/profile/antmasiello.bsky.social

 

The westerly wind burst earlier in the month was pretty strong and is worth a further dive into the data/better analysis. Quick glance at Reanalysis daily data in Nov, for the equatorial 850mb zonal wind anomaly at 120°W since 1950, shows it was the strongest since the 1997 and 1998 November events.

[mitchnick]

50 minutes ago, bluewave said:

I recently pointed out how unusual that WWB was in the EPAC was. Thanks to Anthony for pointing out how anomalous it was. Strongest November WWB since 97-98 super El Niño at 120W. This extreme event is part of why the atmosphere has shifted to such a strong +AAM and more Nino-like pattern. 
 

https://bsky.app/profile/antmasiello.bsky.social

 

The westerly wind burst earlier in the month was pretty strong and is worth a further dive into the data/better analysis. Quick glance at Reanalysis daily data in Nov, for the equatorial 850mb zonal wind anomaly at 120°W since 1950, shows it was the strongest since the 1997 and 1998 November events.

I'll never forget his response to one of my posts on Easternwx 6 days before PD2 (2/03) outlining the initial overruning snows imby (BWI) and the ultimate evolution of the storm. Not to belittle any other poster here or anywhere else, but he's the best met I've seen. I'm just sorry he doesn't post here anymore. 

[michsnowfreak]

19 minutes ago, mitchnick said:

I'll never forget his response to one of my posts on Easternwx 6 days before PD2 (2/03) outlining the initial overruning snows imby (BWI) and the ultimate evolution of the storm. Not to belittle any other poster here or anywhere else, but he's the best met I've seen. I'm just sorry he doesn't post here anymore. 

What was his username? I don't seem to remember 

[mitchnick]

2 minutes ago, michsnowfreak said:

What was his username? I don't seem to remember 

HM

[GaWx]

 I just noticed that NG is currently down ~7% from yesterday. I don’t know why it is down sharply. Often that is a sign that the most recent EPS/GEFS runs are warmer than prior runs in the E US especially on days 8-16. But sometimes that can be due to other factors like lots of profit-taking after a huge runup that had actually occurred through yesterday. Also, yesterday had a weekly inventory report, which could have been bearish. I’ll see if I can find out. Admittedly I haven’t checked the latest EPS/GEFS. Anyone know if they’re as cold in the E 1/3 if the US as yesterday’s very cold runs?

[Stormchaserchuck1]

15 minutes ago, GaWx said:

 I just noticed that NG is currently down 6% from yesterday. I don’t know why it is down sharply. Often that is a sign that the most recent EPS/GEFS runs are warmer than prior runs in the E US especially on days 8-16. But sometimes that can be due to other factors like lots of profit-taking after a huge runup that had actually occurred through yesterday. Also, yesterday had a weekly inventory report, which could have been bearish. I’ll see if I can find out. Admittedly I haven’t checked the latest EPS/GEFS. Anyone know if they’re as cold in the E 1/3 if the US as yesterday’s very cold runs?

The long range is not as cold, with a strong -PNA/+NAO trying to develop by Day 16.  The model fluctuates a lot, but what the gfs ens are trying to do at hr384 could be 60s in the East a few days later. 

[40/70 Benchmark]

1 minute ago, Stormchaserchuck1 said:

The long range is not as cold, with a strong -PNA/+NAO trying to develop by Day 16.  The model fluctuates a lot, but what the gfs ens are trying to do at hr384 could be 60s in the East a few days later. 

Sounds about right...any semblance of winter is always eradicated before the holiday.

[brooklynwx99]

26 minutes ago, Stormchaserchuck1 said:

The long range is not as cold, with a strong -PNA/+NAO trying to develop by Day 16.  The model fluctuates a lot, but what the gfs ens are trying to do at hr384 could be 60s in the East a few days later. 

nothing about this says 60s to me. all of the cold air is on this side of the globe and cross polar flow remains established 

[GaWx]

46 minutes ago, Stormchaserchuck1 said:

The long range is not as cold, with a strong -PNA/+NAO trying to develop by Day 16.  The model fluctuates a lot, but what the gfs ens are trying to do at hr384 could be 60s in the East a few days later. 

Thanks, Chuck. I just looked for the first time since yesterday. I see what you’re saying. But the latest GEFS/EPS are still pretty solidly cold dominated through day 16/15 in the E US with E US troughing. And trying to predict a few days later is full of danger as even predicting late week 2 isn’t so easy as we all know. Now are the full runs subtlety warmer than yesterday’s full runs while still quite cold? That’s very hard to determine without the actual HDD output, which I haven’t seen in awhile. Some of the 2M temperature change maps suggest that. And after a huge runup in NG to 13 month highs, that as you know could easily be all it takes for lots of profit-taking, especially if inventory is on the relative high side.

[snowman19]

1 hour ago, brooklynwx99 said:

nothing about this says 60s to me. all of the cold air is on this side of the globe and cross polar flow remains established 

I don’t think the issue comes the 1st 2 weeks of December. The thing that would support the NAO and AO/NAM going very positive is the SPV. The SPV is forecast to get extremely strong and cold on the models and “couple” with the troposphere. They also have it moving directly over the pole. *IF* that happens it may be a problem going into mid-December

 

 

 

 

[bluewave]

One thing to note for the first week of December is that the 850 mb temperature departures are forecast to be colder than the 2m since the Northern Hemisphere snow cover is still near record lows and will need some time to catch up. 
 

 

[michsnowfreak]

49 minutes ago, 40/70 Benchmark said:

Sounds about right...any semblance of winter is always eradicated before the holiday.

White christmas on the east coast/new england this year lol. There is no possible meteorological explanation why those grinch storms always hit you at Christmas other than bad luck. Its bound to change. Our general White Christmas (1"+ snowcover) climo here is 50/50 and there's been no trend away from that in recent years.

[snowman19]

35 minutes ago, snowman19 said:

I don’t think the issue comes the 1st 2 weeks of December. The thing that would support the NAO and AO/NAM going very positive is the SPV. The SPV forecast to get extremely strong and cold on the models and “couple” with the troposphere. They also have it moving directly over the pole. *IF* that happens it may be a problem going into mid-December

 

 

 

 

Just to add to this SPV disco, if the MJO (4-6) forcing does start to exert itself and we go back to a La Niña/-PDO like atmosphere with a -PNA, as @Stormchaserchuck1 mused, at the same time of a potential coupled SPV forced +NAO/+AO, then yes, the pattern could get very mild. And as I discussed yesterday, there is a possibility we go Niña in region 3.4 by the end of December with a projected EWB next month. “Commodity weather” pointed out that there have been cold-neutral ENSO Novembers that have gone La Niña by the New Year in the past. I don’t know what to think right now after this total mismatch we’re seeing to start December TBH

[bluewave]

32 minutes ago, michsnowfreak said:

meteorological explanation why those grinch storms always hit you at Christmas other than bad luck. Its bound to change

The 2nd half of December has been warming at a faster rate than the 1st half around the Northeast spots like NYC over the last 30 years. Every year since 2011 there has been a warm up between the 17th and 25th going over 55°. So it would be quite an accomplishment if we got a relaxation of this pattern for even one year. 
 

December 17 to 25 maximum temperature NYC over 55° every year since 2011

 

Time Series Summary for NY CITY CENTRAL PARK, NY
Click column heading to sort ascending, click again to sort descending.

2023-12-25	62	0
2022-12-25	58	0
2021-12-25	60	0
2020-12-25	61	0
2019-12-25	57	0
2018-12-25	61	0
2017-12-25	55	0
2016-12-25	58	0
2015-12-25	72	0
2014-12-25	62	0
2013-12-25	71	0
2012-12-25	56	0
2011-12-25	62	0
2010-12-25	40	0

 

 

[40/70 Benchmark]

35 minutes ago, snowman19 said:

Just to add to this SPV disco, if the MJO (4-6) forcing does start to exert itself and we go back to a La Niña/-PDO like atmosphere with a -PNA, as @Stormchaserchuck1 mused, at the same time of a potential coupled SPV forced +NAO/+AO, then yes, the pattern could get very mild. And as I discussed yesterday, there is a possibility we go Niña in region 3.4 by the end of December with a projected EWB next month. “Commodity weather” pointed out that there have been cold-neutral ENSO Novembers that have gone La Niña by the New Year in the past. I don’t know what to think right now after this total mismatch we’re seeing to start December TBH

2008-2009 is one prominent example.

[GaWx]

Eric Webb discovered ABNA and that the -ABNA is driving the current/upcoming cold E US pattern. Anyone here knowledgeable about ABNA? It’s actually not a new index though we had previously never heard of it. Regardless, not having a daily forecast nor a monthly history of it makes it less useful to me though the DJF mean is shown on a graph in this Eric tweet:

 

[GaWx]

12Z GEFS is about as cold run overall as any prior run through day 11. But days 12-16 remain to be seen. Also, fwiw, it has a significant increase in members with a tropical cyclone in the W Caribbean next week….interesting.

 Edit: 12Z GEFS isn’t the coldest days 12-16 but it is still cold overall thus making the total run another cold one.

 12Z Euro: 15 day run is about as cold as any yet per my eyeballs with 4 Canadian highs including current one plunging down