ENSO Updates (2007 thru 2023)

[Kingarabian]

No disrespect to Andy Hazleton, but this event wont get to super Nino levels with this atompshere.

[Dean_175]

No disrespect to Andy Hazleton, but this event wont get to super Nino levels with this atompshere.

"Already super going by eastern regions" isn't a very good statement. The eastern region can be warm even during La Nina (ie. 1998) and nino3.4 is used precisely because it provides better correlation to the atmosphere due to the warmer base state. The global ENSO teleconnections in particular depend far more on what is happening in that 3.4 region than near the Galapagos and Peru. I went back and looked at every El Nino that had a trimonthly of 2.0C or higher (1965, 1972, 1982, 1997, 2015) and cannot find a single one with weaker westerly wind anomalies near the dateline than current. 2012 and 2014 were very warm in the east, and we know what happened those years. Not saying that will be the case this year (highly unlikely to be a complete bust as SSTs are warmer). AMJ came in at 0.5C and while most upcoming Ninos that had that value turned out to be strong to super, that period is still within the spring predictability barrier and correlation to peak is probably not that robust (compared to correlation between August and January). A strong peak like 1991 is hinted at by the models and is what I personally think is the most likely scenario, but atmospheric coupling was already much stronger by this time during that year. If coupling occurs after this new WWB, then the event may have a chance of becoming quite impressive. If no coupling until late summer or fall then I could see this event peaking as only a moderate. That said, if you look at the map of real SSTs rather than anomalies, it isn't exactly surprising that we aren't seeing frequent big WWBs. The warmest waters of the equatorial Pacific continue to be near Indonesia (albeit a bit to the east). By this time in 1997, with the combination of negative anomalies in the west and positive anomalies in the east, the warmest actual sea surface temperatures were displaced all the way to around 150W; hence a fairly continuous sequence of WWB extending to the end of the year. We have positive anomalies in the far west currently. While this means that there is still gas in the tank so to speak, it doesn't help move the convection eastward.

[zzzh]

Lol, May-June MEI came in to be 0.2. At the same time for 1997 and 2015, they were 2.4 and 1.7 respectively. The atmosphere is still far from El Nino, let alone super Nino.

[Yellow Evan]

MEI of .2 continues the trend of steady improvement considering it was -.7 as late as FM. Its not far from El Niño but yea the atmospheric coupling will generally continue to lag behind SSTs.

[dexterlabio]

Imagine if the atmosphere starts to fully cooperate by the end of the year like what happened in 2014.

[Kingarabian]

CFS has a WWB reaching 180 by July 21 but stops there. Shows much stronger strades over the CPAC during August.

GFS and Euro have a strong trade burst over the CPAC by July 21.

[SFLcane]

[Yellow Evan]

https://i.postimg.cc/6353p82G/sst.png

GFS keeps predicting really strong CPAC trades anytime intraseasonal forcing gets over the MC and while conceptually this makes sense, they never verify at the extent modeled.

[Kingarabian]

https://i.postimg.cc/6353p82G/sst.png

GFS keeps predicting really strong CPAC trades anytime intraseasonal forcing gets over the MC and while conceptually this makes sense, they never verify at the extent modeled.

MJO/-CCKW over the MC during the summer almost always leads to strong CPAC trades. Euro agrees with the GFS as well.

[Ntxw]

The eastern regions continue to warm, while the western regions remains flat, we're seeing a lot more of the same. 3.4 may go back to 1C come Monday's update.

[dexterlabio]

Are the forecasted strong trades supposed to cool down the Nino regions? Because there had been a handful of forecasts showing strong trades particularly in the eastern Nino regions, but the temperature has been holding steady at least. Nino 1.2 has been hovering between 2.6C and 2.9C since last Spring.

[USTropics]

Are the forecasted strong trades supposed to cool down the Nino regions? Because there had been a handful of forecasts showing strong trades particularly in the eastern Nino regions, but the temperature has been holding steady at least. Nino 1.2 has been hovering between 2.6C and 2.9C since last Spring.

Stronger trade winds tend to suppress El Nino events. Since trade winds are prevailing easterly winds that blow near the equator from east to west, they typically push warm surface waters toward the western Pacific resulting in the upwelling of cold, nutrient-rich waters in the eastern Pacific. This in turn steepens the thermocline.

When trade winds strengthen or persistently blow stronger than usual, they enhance the oceanic processes that promote upwelling of cold waters in the eastern Pacific. This causes the surface waters to be colder than average, which creates unfavorable conditions for the development and sustenance of El Nino. The colder waters help maintain the typical temperature gradient across the Pacific and act as a negative feedback mechanism, suppressing the warming associated with El Nino.

On the other hand, during strengthening El Nino events, the trade winds typically weaken or even reverse (e.g., Westerly Wind Burst events or WWBs), leading to reduced upwelling of cold waters and allowing warm surface waters to spread across the central and eastern Pacific (i.e., the thermocline gradient is reduced). This weakening of the trade winds is typically a crucial factor in the initiation and intensification of El Nino.

[dexterlabio]

Stronger trade winds tend to suppress El Nino events. Since trade winds are prevailing easterly winds that blow near the equator from east to west, they typically push warm surface waters toward the western Pacific resulting in the upwelling of cold, nutrient-rich waters in the eastern Pacific. This in turn steepens the thermocline.

When trade winds strengthen or persistently blow stronger than usual, they enhance the oceanic processes that promote upwelling of cold waters in the eastern Pacific. This causes the surface waters to be colder than average, which creates unfavorable conditions for the development and sustenance of El Nino. The colder waters help maintain the typical temperature gradient across the Pacific and act as a negative feedback mechanism, suppressing the warming associated with El Nino.

On the other hand, during strengthening El Nino events, the trade winds typically weaken or even reverse (e.g., Westerly Wind Burst events or WWBs), leading to reduced upwelling of cold waters and allowing warm surface waters to spread across the central and eastern Pacific (i.e., the thermocline gradient is reduced). This weakening of the trade winds is typically a crucial factor in the initiation and intensification of El Nino.

Based on that, the strong trades previously forecasted should have brought down the temps at the Nino regions, particularly in Nino 1+2 which remains scorching hot at the moment. That is why I'm starting to think that the forecasts of strong trades were a little bit overdone. If anything, the actual strength of the trade winds was just enough to put a cap on the warming trend.

[xtyphooncyclonex]

This El Niño event will most likely not reach the BOM's aggressive forecasts, but it appears to have weathered predictions of strong trades. Had they panned out, we wouldn't be seeing much of the warmth we have at the moment. Looking at raw anomaly maps, my amateur eyes tell me this looks like a textbook strong Niño in the making. The warming in the eastern regions seems impressive and robust.

At the same time, the atmospheric response hasn't met expectations either. It feels that there's lots of conflicting signals. It's already July, and it seems that we can't say whether or not this has turned out to be a bust. This is looking less likely to look be a 2012 or 2014.

[Kingarabian]

Stronger trade winds tend to suppress El Nino events. Since trade winds are prevailing easterly winds that blow near the equator from east to west, they typically push warm surface waters toward the western Pacific resulting in the upwelling of cold, nutrient-rich waters in the eastern Pacific. This in turn steepens the thermocline.

When trade winds strengthen or persistently blow stronger than usual, they enhance the oceanic processes that promote upwelling of cold waters in the eastern Pacific. This causes the surface waters to be colder than average, which creates unfavorable conditions for the development and sustenance of El Nino. The colder waters help maintain the typical temperature gradient across the Pacific and act as a negative feedback mechanism, suppressing the warming associated with El Nino.

On the other hand, during strengthening El Nino events, the trade winds typically weaken or even reverse (e.g., Westerly Wind Burst events or WWBs), leading to reduced upwelling of cold waters and allowing warm surface waters to spread across the central and eastern Pacific (i.e., the thermocline gradient is reduced). This weakening of the trade winds is typically a crucial factor in the initiation and intensification of El Nino.

Based on that, the strong trades previously forecasted should have brought down the temps at the Nino regions, particularly in Nino 1+2 which remains scorching hot at the moment. That is why I'm starting to think that the forecasts of strong trades were a little bit overdone. If anything, the actual strength of the trade winds was just enough to put a cap on the warming trend.

The strong trades were never close to Nino 1+2. Trades have been much weaker than normal in that region.

[cycloneye]

 https://twitter.com/BenNollWeather/status/1677458118949867520

The latest ECMWF seasonal guidance indicates that El Niño will likely reach strong levels by August-September

100% of members indicate a strong event will be in place by November and continue through the end of 2023.

 https://twitter.com/BenNollWeather/status/1677458122187886592

What is the confidence level on a strong El Niño?

The red blocks indicate that the ECMWF ensemble unanimously predicts a strong El Niño by November.

Over 70% of members show a very strong event developing (>2.0˚C anomaly in the central equatorial Pacific) by December.

[dexterlabio]

Stronger trade winds tend to suppress El Nino events. Since trade winds are prevailing easterly winds that blow near the equator from east to west, they typically push warm surface waters toward the western Pacific resulting in the upwelling of cold, nutrient-rich waters in the eastern Pacific. This in turn steepens the thermocline.

When trade winds strengthen or persistently blow stronger than usual, they enhance the oceanic processes that promote upwelling of cold waters in the eastern Pacific. This causes the surface waters to be colder than average, which creates unfavorable conditions for the development and sustenance of El Nino. The colder waters help maintain the typical temperature gradient across the Pacific and act as a negative feedback mechanism, suppressing the warming associated with El Nino.

On the other hand, during strengthening El Nino events, the trade winds typically weaken or even reverse (e.g., Westerly Wind Burst events or WWBs), leading to reduced upwelling of cold waters and allowing warm surface waters to spread across the central and eastern Pacific (i.e., the thermocline gradient is reduced). This weakening of the trade winds is typically a crucial factor in the initiation and intensification of El Nino.

Based on that, the strong trades previously forecasted should have brought down the temps at the Nino regions, particularly in Nino 1+2 which remains scorching hot at the moment. That is why I'm starting to think that the forecasts of strong trades were a little bit overdone. If anything, the actual strength of the trade winds was just enough to put a cap on the warming trend.

The strong trades were never close to Nino 1+2. Trades have been much weaker than normal in that region.

I believe there were solid trade bursts in 180 to 100E back in April/early May.

[dexterlabio]

At the same time, the atmospheric response hasn't met expectations either. It feels that there's lots of conflicting signals. It's already July, and it seems that we can't say whether or not this has turned out to be a bust. This is looking less likely to look be a 2012 or 2014.

El Niño is already here so this is far from a bust. although there is a chance that the strong El Niño may still bust.

[JetFuel_SE]

https://twitter.com/BenNollWeather/status/1677458118949867520

The latest ECMWF seasonal guidance indicates that El Niño will likely reach strong levels by August-September

100% of members indicate a strong event will be in place by November and continue through the end of 2023.

https://twitter.com/BenNollWeather/status/1677458122187886592

What is the confidence level on a strong El Niño?

The red blocks indicate that the ECMWF ensemble unanimously predicts a strong El Niño by November.

Over 70% of members show a very strong event developing (>2.0˚C anomaly in the central equatorial Pacific) by December.

Doesn't the ECM have a warm bias?

[LarryWx]

https://twitter.com/BenNollWeather/status/1677458118949867520

The latest ECMWF seasonal guidance indicates that El Niño will likely reach strong levels by August-September

100% of members indicate a strong event will be in place by November and continue through the end of 2023.

https://twitter.com/BenNollWeather/status/1677458122187886592

What is the confidence level on a strong El Niño?

The red blocks indicate that the ECMWF ensemble unanimously predicts a strong El Niño by November.

Over 70% of members show a very strong event developing (>2.0˚C anomaly in the central equatorial Pacific) by December.

Doesn't the ECM have a warm bias?

1. Yes, ECM is warm biased.

2. We're 1/4 into July and yet OISST is still only at +1.0, which implies that ERSST (used to determine the ONI and how strong a Nino) based on recent differences is likely only ~+0.9. The latest BoM had reduced July from +1.8 to +1.5. I'm getting close to calling even the +1.5 a bust. It would take a massive warming of ERSST to +2+ the next 3 weeks for +1.5 July ERSST to occur. 
 
 Looking at OISST 3.4 weekly anomalies for oncoming El Niño since 1982, there are only two 3 week periods that warmed that rapidly:

-Sep 1982: warmed 1.1, but SOI was sub -20 Aug/Sep

-Mar 2014: warmed 1.4 but SOI was -13 2/21/14-3/21/14

 So, the SOI was strongly - in advance and during these two periods. The current 30 day is way up at +3. It does appear to be headed back to modest -SOI next weekend followed by a week+ of -SOI thanks to low Tahiti SLP. However, with Darwin SLP remaining kind of low much of that period, the oncoming -SOI doesn't look strong at this point until perhaps ~7/22. By then, it is probably too late to have much impact for July 3.4 SST anomalies.
 
 The OHC is quite warm at ~+1.4, but that's not warm enough to support a +2.0 in 3.4 within 3 weeks. In Sep of 1982, the OHC had warmed from +1.11 two months earlier to way up at +1.86. From 9/6/82 to 9/27/82, 3.4 SSTs warmed from +0.6 to +1.7. 

  In March of 2014, the OHC was way up at +1.60 after a massive warming from only +0.39 the month before.

 Thus, I see only a very small chance for a rapid warming in 3.4 the rest of this month. So, it looks like another too warm bust for BoM in July.