El Nino 2023-2024

[Terpeast]

28 minutes ago, bluewave said:

I shifted the map closer to the Northeast so we could see the finer details. While the 2020s are still young, our strong -AO blocking Decembers of 2022 and 2020 were much further south than their counterparts from previous decades. December 2022 was the furthest south block on record with a monthly -AO value lower than-1.5 and -PNA for the month. Same goes for December 2020 which was furthest south based for a +PNA. We could expand to compare January 2021 which had an -AO block lower than -1.5 which was further south based than previous decades. We could also include other months of the year but not enough space in this post to compare.

2020s December -AO -PNA

Earlier -AO -PNA

 

December 2020 -AO +PNA

 

Earlier -AO +PNA

 

 

I prefer looking at the entire northern hemisphere and expanding the gpm scale.

You only have the scale at +/- 50 gpm, which leaves out a lot of detail and we don’t know where the center of blocking really is. Then zooming into only north america cuts out a lot of other details, like the interplay between blocking and aleutian lows/ridges. 

Besides 1983 and 1996 had blocking pretty far south, enough to cover NE with above normal height anomalies. 

Finally, the 2020s were all ninas with moderate to strong -MEI. This is the first year in the 20s that the MEI has finally flipped into el nino territory. We don’t have a sample size to work with in the 20s.

[Terpeast]

@bluewave Pertinent to our discussion, I like what this met was saying about HL blocking (starting at 10 min):

While he didn’t specifically mention the AMO, he showed the interplay of blocking between low pressure systems in other parts of the globe, and how that delivers cold air outbreaks. We have to look at the entire hemisphere when looking at blocking. 

[bluewave]

52 minutes ago, Terpeast said:

I prefer looking at the entire northern hemisphere and expanding the gpm scale.

You only have the scale at +/- 50 gpm, which leaves out a lot of detail and we don’t know where the center of blocking really is. Then zooming into only north america cuts out a lot of other details, like the interplay between blocking and aleutian lows/ridges. 

Besides 1983 and 1996 had blocking pretty far south, enough to cover NE with above normal height anomalies. 

Finally, the 2020s were all ninas with moderate to strong -MEI. This is the first year in the 20s that the MEI has finally flipped into el nino territory. We don’t have a sample size to work with in the 20s.

We were talking specifically about the Northeast so that’s why I zoomed in.

Most people don’t realize how unusual last winter was. NYC had the lowest snowfall ever for any single winter month with an -AO reading lower than -2.5 by a wide margin. Plus it  was the warmest winter out of the bunch by and equally wide margin.

1983 and 1996 were nowhere near as far south with the blocking as recent years.

Sure we are dealing with small sample sizes since we are only several years into a new decade. But what we have been seeing with heights building into the Northeast is something new with -AO s of these magnitudes so far. 

Plus you agreed with me with your AMO composite so not sure what our differences are.

NYC snowfall with monthly DJF  -AO reading dipping below -2.5 and average temperature 

22-23…2.3”….41.0°

10-11…61.9….32.8°

09-10…51.4….33.8°

84-85…24.1….36.4°

77-78….50.7….30.3°

76-77….24.5….28.4°

68-69…30.2….32.9°

65-66…21.4…..35.9°

62-63….16.3….29.9°

 

 

[Terpeast]

11 minutes ago, bluewave said:

We were talking specifically about the Northeast so that’s why I zoomed in.

Most people don’t realize how unusual last winter was. NYC had the lowest snowfall ever for any single winter month with an -AO reading lower than -2.5 by a wide margin. Plus it  was the warmest winter out of the bunch by and equally wide margin.

1983 and 1996 were nowhere near as far south with the blocking as recent years.

Sure we are dealing with small sample sizes since we are only several years into a new decade. But what we have been seeing with heights building into the Northeast is something new with -AO s of the magnitudes so far. 

Plus you agreed with me with your AMO composite so not sure what our differences are.

NYC snowfall with monthly DJF  -AO reading dipping below -2.5 and average temperature 

22-23…2.3”….41.0°

10-11…61.9….32.8°

09-10…51.4….33.8°

84-85…24.1….36.4°

77-78….50.7….30.3°

76-77….24.5….28.4°

68-69…30.2….32.9°

65-66…21.4…..35.9°

62-63….16.3….29.9°

 

 

The difference here is that I’m saying the far-south blocking has indeed happened before in specific cases (note that I’m not blending them), and the MA still got hit. 

Where I agree with you is that this kind of blocking will be more frequent going forward. I guess our difference lies in what really happens in our backyards when we get those blocking episodes.

In an el nino, I say bring it on.

[bluewave]

Just now, Terpeast said:

The difference here is that I’m saying the far-south blocking has indeed happened before in specific cases (note that I’m not blending them), and the MA still got hit. 

Where I agree with you is that this kind of blocking will be more frequent going forward. I guess our difference lies in what really happens in our backyards when we get those blocking episodes.

In an el nino, I say bring it on.

This far south blocking hasn’t happened before with the -AO magnitudes that I mentioned. But we did have much weaker -AOs in the past that did build this far south. 

While the blocking has been the strongest on record in Canada from May to October, it hasn’t allowed for much cooler air in North America. Like the 500mb heights expanding so much that there was no cool air available for the troughs.

I am hoping that we can get some of these decent -AO +PNA intervals during the winter to give us a better snowfall outcome than last winter even if there isn’t much cold air available for the troughs to work with. 

[thunderbolt]

[40/70 Benchmark]

1 minute ago, thunderbolt said:

Who tweeted that?

[40/70 Benchmark]

13 minutes ago, bluewave said:

This far south blocking hasn’t happened before with the -AO magnitudes that I mentioned. But we did have much weaker -AOs in the past that did build this far south. 

While the blocking has been the strongest on record in Canada from May to October, it hasn’t allowed for much cooler air in North America. Like the 500mb heights expanding so much that there was no cool air available for the troughs.

I am hoping that we can get some of these decent -AO +PNA intervals during the winter to give us a better snowfall outcome than last winter even if there isn’t much cold air available for the troughs to work with. 

Why would a weaker -AO block build further south than more extreme ones? Shouldn't the opposite be the case?

[thunderbolt]

8 minutes ago, 40/70 Benchmark said:

Who tweeted that?

David Birch ocean, data analyst

[bluewave]

1 hour ago, 40/70 Benchmark said:

Why would a weaker -AO block build further south than more extreme ones? Shouldn't the opposite be the case?

Because the more extreme ones usually had a stronger 500 mb vortex near the Northeast than in recent years. 

[pasnownut]

13 hours ago, Terpeast said:

So I went down this rabbit hole... (lol)

I compared the AMO-H5 regression with the months containing the biggest MA snowstorms going back to 1966.

Here is the AMO-H5 regression, which supports the theory that a warm Atlantic promotes HL blocking further south or SW than Greenland:

 

I tried to explore the amplitude of the AMO and its relationship with HL blocking, but I couldn't find anything compelling. I think the ENSO variance (and other tele's) washes it out when I combine too many years.

 

Next, I compared the above chart to the months containing (or leading up to) the biggest MA snowstorms, starting with the holy grail of 2010:

Look how pretty far south that blocking was. Very similar to the AMO-H5 regression, except the trough under the block was much deeper (stronger jet). Also, the presence of an aleutian low was key. 

 

Next up, 2016:

That block was pretty far north up Baffin Bay, paired with a strong aleutian low and a strong STJ. I think it was the pacific that really drove this one without much need for blocking. Or something is getting washed out with mixed signals throughout the full month.

 

Now, Feb 2003:

That's a weird one. No blocking, except all the way out to scandinavia. There's even a SE ridge OTS. Canada was very cold, so it was one big massive overrunning event as opposed to a miller A bomb.

 

Next up, 1996:

A lot of mixed signals resulting in a washed out look, but you can see a -NAO with two areas of blocking. One primary over Scandinavia, and one secondary off Newfoundland. That's pretty far south for a block, and yet, the MA went on a massive heater... despite a weak aleutian ridge signal. Strange but fun winter... it could easily have gone the other way.

 

Next, 1987:

One area of east-based blocking up over Iceland with a strong -NAO and 50/50 trough. Presence of Aleutian troughing. 

 

Now, 1983:

 

That block was so far south that we even have troughing over Greenland, with +H5 anomalies over New England. And yet we got a historic KU. Very strong aleutian low a big player here.

 

PD1 1979:

Block was far south/southwest of its typical orientation, and PDI was a cold storm that ranks #3 at DCA. No other storm has been able to top this one at this specific airport site. We also see western troughing and a weak aleutian ridge here.

 

Finally, 1966:

This block was pretty far southwest, accompanied by a noteworthy low to the west of Europe. 

 

All in all, a further south/southwest based block should actually be reassuring for us folks in the MA and SE as it likely helps, not hurts, our prospects of getting a big snowstorm as long as the other tele's support it, namely ENSO and PDO. But if you live in Maine or Boston, it's probably bad news (and I'm sure you've suspected this already). NYC is kinda in between.

 

 

Rabbit hole or not, lots of good stuff here.  Thanks for sharing.

[bluewave]

1 hour ago, 40/70 Benchmark said:

Who tweeted that?

Out of phase PDO since the spring with some of the weakest developing El Niño WWBs on record.

To understand the diversity of the El Niño-Southern Oscillation (ENSO) under the background of Pacific decadal oscillation (PDO) during recent decades, characteristics of westerly wind bursts (WWBs) during positive and negative phases of the PDO were analyzed. It is shown that, during the ENSO developing period, the El Niño evolution may be affected by stronger or more frequent WWBs in the positive PDO phase than in the negative PDO phase. The sustained effects of atmospheric dynamics on the equatorial ocean can be indicated by the accumulated WWB strength, which contains most WWB characteristics, including the accumulated days, occurrence frequency, strength, and spatial range of WWBs. The synoptic/climate systems that are directly related to WWBs show a wider spatial distribution in the positive PDO phase than in the negative PDO phase.

 

 

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[pasnownut]

3 hours ago, 40/70 Benchmark said:

Care to address his point, as opposed to simply berating him?

I'm going to let you in on little secret....Paul Roundy farts and pisses like the rest of us and is sometimes wrong. I would suggest prying open your mind and engaging in a bit more independent thought, as opposed to clinging to his feedback like a life buoy. I don't know how many times I have seen pro meteorologists express an opinion that I was quite confident was wrong and I ended up being right. The most seasoned professionals are not infallible, especially within a frontier science such as seasonal forecasting...medium range is difficult enough.

Pin worthy post. Part of the fun IMO as even a hobbyist can add some value as the constant ebb and flow of weather is ever changing, and we seem to play catch up wrt what we see and what may happen.  Not for a second would I ever discount ANY met/pros offerings, unless a bias is present in what they offer to the masses.  

[Terpeast]

I think with the PDO rising to neutral, but with the lack of upper OHC, I think this nino holds at around 1.6-1.7 at least for the next few weeks with weakening trades. 

[40/70 Benchmark]

9 minutes ago, pasnownut said:

Pin worthy post. Part of the fun IMO as even a hobbyist can add some value as the constant ebb and flow of weather is ever changing, and we seem to play catch up wrt what we see and what may happen.  Not for a second would I ever discount ANY met/pros offerings, unless a bias is present in what they offer to the masses.  

Intelligence helps, but in my opinion, the characteristic most highly correlated with forecast proficiency is an open mind and the understanding that something can be learned from everyone. I have learned that the hard way after being really pig-headed for awhile.

[pasnownut]

4 minutes ago, 40/70 Benchmark said:

Intelligence helps, but in my opinion, the characteristic most highly correlated with forecast proficiency is an open mind and the understanding that something can be learned from everyone. I have learned that the hard way after being really pig-headed for awhile.

Like many others here, you add great value, and the open minded - level headed approach to offerings is easy to see. 

Keep up the good work as this hobbyist has learned so much from the likes of you/others. 

IMO the PDO is and has been the biggest player in what we see here in the east, and if we can manage to stay neutralish in the means, it may be much more "normalish" here in the east... as all of last years good indies, were offset by it IMO.  

[40/70 Benchmark]

JMA EMI forecast has been slowly inching upwards since last spring....now getting near 2003 with a peak of .72 (.60 last month) in Feb. 

[donsutherland1]

15 hours ago, GaWx said:

The last few Euro weeklies’ mean (thickest blue line) have shown a stronger than normal Nov SPV, suggesting that a +AO would be favored, along with a weakening to a near normal SPV in early Dec fwiw:

The tendency toward a strengthening SPV may be starting to show up in the extended range of the AO forecast, which is now showing a pronounced rise.

[40/70 Benchmark]

Just now, donsutherland1 said:

The tendency toward a strengthening SPV may be starting to show up in the extended range of the AO forecast, which is now showing a pronounced rise.

That is on par with the phase 8/1 November plots.

[Terpeast]

5 minutes ago, 40/70 Benchmark said:

JMA EMI forecast has been slowly inching upwards since last spring....now getting near 2003 with a peak of .72 (.60 last month) in Feb. 

Is that the new MEI value? 

[40/70 Benchmark]

1 hour ago, Terpeast said:

Is that the new MEI value? 

No EMI forecast..current value is about neutral. That is the forecast peak in February.

[40/70 Benchmark]

Last Update from me before I publish next month.

https://easternmassweather.blogspot.com/2023/10/final-enso-update-of-fall.html

[pasnownut]

29 minutes ago, 40/70 Benchmark said:

That is on par with the phase 8/1 November plots.

Reading a couple pages back that it was suggested that MJO influence may not be as big a player this year.  How much stock do you put into that suggestion? 

The weenie in me sees 8/1 and starts to get a tingle (knowing its only for Nov), but the realist is trying to temper expectations and figure out where the money lies in searching for longer lead clues and what tellies/indicies may take hold of the wheel on the winter 23-24 bus.  Thoughts?

[snowman19]

No...current value is about neutral. That is the forecast peak in February.

Doesn’t match up at all with this. Not one value above +0 right through March on any model on that chart. Also, region 1+2 is warming again, up to +2.6C. Regardless of what happens in 3.4 this one is not becoming a Modoki

https://cyclonicwx.com/data/sst/crw_ssta_graph_nino12.png

[40/70 Benchmark]

30 minutes ago, snowman19 said:

Doesn’t match up at all with this. Not one value above +0 right through March on any model on that chart. Also, region 1+2 is warming again, up to +2.6C. Regardless of what happens in 3.4 this one is not becoming a Modoki

 

https://cyclonicwx.com/data/sst/crw_ssta_graph_nino12.png

 

This reflects the current value:

Not a forecast. There are plenty of values above 1 in the forecast table, including the mean of .4.

If you look at the data table, they are referencing the multi-model mean...I am using the JAMSTEC ensemble mean, which I normally do for EMI. They have JMA at .60 there, but that is as of 10/1....it ran again on 10/20 and was .72.

https://www.jamstec.go.jp/aplinfo/sintexf/e/seasonal/outlook.html

[40/70 Benchmark]

29 minutes ago, pasnownut said:

Reading a couple pages back that it was suggested that MJO influence may not be as big a player this year.  How much stock do you put into that suggestion? 

The weenie in me sees 8/1 and starts to get a tingle (knowing its only for Nov), but the realist is trying to temper expectations and figure out where the money lies in searching for longer lead clues and what tellies/indicies may take hold of the wheel on the winter 23-24 bus.  Thoughts?

I suspect we will see some nice stretches of 8 and 1, especially later in the season, but there will probably be some la nina like thaws.

[Terpeast]

1 hour ago, 40/70 Benchmark said:

No...current value is about neutral. That is the forecast peak in February.

Gotcha. Just noticed "EMI", not "MEI". Dyslexic moment 

[pasnownut]

58 minutes ago, 40/70 Benchmark said:

I suspect we will see some nice stretches of 8 and 1, especially later in the season, but there will probably be some la nina like thaws.

Hope so.  As I stated earlier, Im only leery of MJO good phases as when they showed last year, it really didn't help as the PDO influence seemed to be the Ace of Spades and trumped all other signals.  Maritime phases seemed to be a lock for torch though (coupled w/ PDO mind you) so I realize this year is notably different.  Just keeping that in the back of my mind while looking at the new hand we're being dealt for this upcoming season.

 

[ORH_wxman]

7 minutes ago, pasnownut said:

Hope so.  As I stated earlier, Im only leery of MJO good phases as when they showed last year, it really didn't help as the PDO influence seemed to be the Ace of Spades and trumped all other signals.  Maritime phases seemed to be a lock for torch though (coupled w/ PDO mind you) so I realize this year is notably different.  Just keeping that in the back of my mind while looking at the new hand we're being dealt for this upcoming season.

 

The only time we had MJO forcing in the 8/1/2 regions last season was the second and third weeks of March.

[so_whats_happening]

17 minutes ago, ORH_wxman said:

The only time we had MJO forcing in the 8/1/2 regions last season was the second and third weeks of March.

Yea if I remember correctly things hit a wall around 6/7.