2024-2025 La Nina

[bluewave]

46 minutes ago, LakePaste25 said:

The long-term climate models expected us to be in more frequent el niño episodes as SSTs and overall background state warmed. Recently we have seen the opposite - more frequent la niña events. It could be that we will eventually see the expected increase of el niño events, while this recent streak of la niña was just a temporary state. 

I suspect we’ll find out one way or another in coming years if the PCC is finally shifting and the EPAC cold pool disappears like the climate models have been forecasting. The big jump in global temperatures since the spring of 2023 with the record east based El Niño early on may indicate a shift. But we’ll probably need years more of data in order to know if this was just a blip or the beginning of the shift the climate models were forecasting.

https://www.nature.com/articles/s41467-024-52731-6

The eastern tropical Pacific has defied the global warming trend. There has been a debate about whether this observed trend is forced or natural (i.e., the Interdecadal Pacific Oscillation; IPO) and this study shows that there are two patterns, one that oscillates along with the IPO, and one that is emerging since the mid-1950s, herein called the Pacific Climate Change (PCC) pattern. 

 

As the tropical Pacific is known to be a climatic pacemaker, for (at least) the near-future this would mitigate global warming via ocean heat uptake and low-level cloud feedbacks. Instead, if the cyclic IPO dominates the recent cooling, we may expect a strong warming when it reverses

[GaWx]

18 minutes ago, bluewave said:

RONI is not meant to rate the actual El Nino intensity only what the SSTs in other regions were relative to Nino 3.4. 

I don’t disagree with what you wrote here from an “official” standpoint or “in name only”. But for all practical purposes, RONI is the more accurate metric imho because of where the SSTs in other tropical regions are is very important to consider.

 I’ll do an extreme hypothetical example to illustrate. Let’s say the average global tropical SST anomaly were +4.5C. And let’s say Nino 3.4 were at +2.3. Officially or in name only it would be a super Nino since it was at +2+. But, for all practical purposes it would actually be a super Niña because 3.4 was 2.2C colder than overall tropical waters. For that metric what’s important is how 3.4 is on a relative basis, which is what I mean by “for all practical purposes.” There’s really nothing El Niño about having a +2.3 in 3.4 other than “in name only” if the surrounding waters are averaging +4.5. In fact it is the opposite.

@PhiEaglesfan712

[Daniel Boone]

22 hours ago, donsutherland1 said:

I suspect that the strengthening PV and lagged response to the development of an AO+/NAO+ will increase the risk for warming late in December. It will take some time to scour out the cold that will dominate during the first half of the month, especially when the PNA is positive.

If we get a +TNH Pattern at regular intervals through the Winter Don we could also wind up with a Feb. 2015 type Pattern at time's. Positive AO/NAO tall PNA Ridge. Eric Webber has brought up a case for that with research backing.

[bluewave]

10 minutes ago, GaWx said:

I don’t disagree with what you wrote here from an “official” standpoint or “in name only”. But for all practical purposes, RONI is the more accurate metric imho because of where the SSTs in other tropical regions are is very important to consider.

 I’ll do an extreme hypothetical example to illustrate. Let’s say the average global tropical SST anomaly were +4.5C. And let’s say Nino 3.4 were at +2.3. Officially or in name only it would be a super Nino since it was at +2+. But, for all practical purposes it would actually be a super Niña because 3.4 was 2.2C colder than overall tropical waters.

It’s like using temperature departures which keep rising every 30 year period. An equally warm month now as many years ago will have a smaller departure relative to the new warmer 30 year baseline. But the actual temperature will be the same. So RONI is more of a relativity index like 30 year climate normals. To me it’s actual temperatures like the Nino 3.4s which have more weight as the means and departures are more relative metrics like RONI. That why I frequently use rankings vs departures. So departures and RONI still have place when weighed against the actual temperatures.

[GaWx]

5 minutes ago, bluewave said:

It’s like using temperature departures which keep rising every 30 year period. An equally warm month now as many years ago will have a smaller departure relative to the new warmer 30 year baseline. But the actual temperature will be the same. So RONI is more of a relativity index like 30 year climate normals. To me it the actual temperatures like the Nino 3.4s which matter and the means and departures are more relative metrics like RONI. 

But if the global tropics were averaging +4.5C but Nino 3.4 were only at +2.3C, why does 3.4 being at +2.3 really matter from El Niño perspective when it is actually a cold area of water relatively speaking and thus should act like La Niña?

[bluewave]

2 hours ago, GaWx said:

But if the global tropics were averaging +4.5C but Nino 3.4 were only at +2.3C, why does 3.4 being at +2.3 really matter from El Niño perspective when it is actually a cold area of water relatively speaking and thus should act like La Niña?

Because as we saw last winter, the 500mb Nino ridge over Canada which drove the record warmth was actually more expansive than much stronger El Niño events like 1997-1998 and 1877-1878. The event was a full fledged super El Niño if you take into account the westward extension of the warmest SSTs near and west of the Dateline and record Nino 4s. This essentially rendered the RONI ineffective last winter as a metric for El Niño strength. We got a super El Niño 500 mb and temperature response over North America and globally. The one possible way RONI worked out was the lower number was reflective of the Niña background which helped to boost the ridge in the East much stronger than past El Niños.

 

 

 

 

[GaWx]

If the global tropics were averaging +4.5C but Nino was only at +2.3C, would you still be thinking of it as a super El Niño other than “in name”? Do you at least see my point?

[PhiEaglesfan712]

To be brutally honest, if the global tropics were averaging +4.5C, I'd be more worried about if the planet was still habitable. For sure, where I currently live would be in the Atlantic Ocean if we reached that point. If the planet was still habitable, I'd probably have moved to West Antarctica by that point.

(And if the global tropics averaging +4.5C and Nino +2.3C scenario happened while I am still living, I'd probably be looking at Eric Webb's Ensemble Oceanic Nino Index to see if he classified it a strong el nino or a strong la nina.)

[Maestrobjwa]

3 hours ago, LakePaste25 said:

The long-term climate models expected us to be in more frequent el niño episodes as SSTs and overall background state warmed. Recently we have seen the opposite - more frequent la niña events. It could be that we will eventually see the expected increase of el niño events, while this recent streak of la niña was just a temporary state. 

Now this is really interesting to me. Now, I'll preface this by saying I'm a layman and amateur weather need. To me, there are some things in weather that just seem so counterintuitive--and the amount of la ninas we've been getting recently always baffled me because common sense would say warming planet, warm waters, more el niño! But then I learned a tad about how trade winds cool the water and it made a little more sense but not a lot. So your saying that it's still possible that we see more ninos?

[GaWx]

The EPO as expected dipped sharply to its lowest level in 13 months after being at its highest since June 4th just 5 days earlier:

2024 11 17  232.92
2024 11 18  182.78
2024 11 19   30.24
2024 11 20 -168.33
2024 11 21 -243.29
2024 11 22 -258.96
2024 11 23 -229.99

[donsutherland1]

8 hours ago, Daniel Boone said:

If we get a +TNH Pattern at regular intervals through the Winter Don we could also wind up with a Feb. 2015 type Pattern at time's. Positive AO/NAO tall PNA Ridge. Eric Webber has brought up a case for that with research backing.

In theory, yes. But a lot would have to happen for such a pattern to actually develop.

[40/70 Benchmark]

December update

https://easternmassweather.blogspot.com/2024/11/december-appears-poised-to-evolve.html