La Niña Ending

[GordMay]

El Niño has a little brother, Atlantic Niño, who lives just across the South American continent, in the equatorial Atlantic Ocean.
Like El Niño, Atlantic Niño is characterized by warmer-than-average sea surface temperatures in the eastern equatorial basin, and weaker-than-average trade winds, throughout the east-central equatorial Atlantic.

Atlantic Niño, in contrast to El Niño, tends to peak in summer when ENSO is usually inactive, is usually shorter in duration, is overall much weaker than ENSO, and has more modest and local climate impacts.
For example, Atlantic Niño often disrupts the West African summer monsoon, leading to reduced rainfall in the Sahel region, and is linked to increased frequency of flooding in northeastern South America and the West African sub-Sahel countries bordering the Gulf of Guinea.

The atmosphere-ocean feedback responsible for the onset of Atlantic Niño is believed to be similar to that of El Niño, a process known as Bjerknes feedback (BF). Recent studies have shown a weakening of the Atlantic Niño variability in the past decades. The changes in eastern equatorial Atlantic SST variability have been attributed to the combined effect of a weakening of the Bjerknes feedback, and increased latent heat flux damping, and to a basin-wide warming, related to climate change.

The Atlantic Niño is just one member of a big extended family that covers much of the tropical and subtropical oceans.
Just like El Niño, Atlantic Niño has a sister, Atlantic Niña, that brings cooler-than-average equatorial Atlantic conditions and the opposite climate impacts as her brother. There are many other siblings , cousins, and distant relatives spanning the Pacific, Atlantic, and Indian Oceans, who share a feature in common: ocean surface temperature anomalies, along eastern boundaries, linked to changes in the upwelling of cooler water from below.

The underlying Bjerknes feedback mechanism consists of three components:
a) a weakening of the equatorial trades (westerly wind anomalies) in the western basin deepens the thermocline in the east;
b) the deepened thermocline reduces upwelling efficiency and warms sea-surface temperature (SST) in the east;
c) warm SSTs further weaken the equatorial trades. Various studies have suggested that a similar feedback mechanism operates in the equatorial Atlantic.

The latent heat flux (Fl) is the exchange of energy between the sea surface and the atmosphere, that occurs when water is evaporated from, or condenses onto, the sea surface.

There are four more relatives in the Atlantic Ocean, Benguela Niño/Niña along the coast of Angola and Namibia, and Dakar Niño/Niña along the east coast of West Africa.
There are four more in the Pacific, California Niño/Niña and Chile Niño/Niña along the California and Chilean coasts, respectively.
In the Indian Ocean, only two have been found so far, Ningaloo Niño/Niña off the west coast of Australia.

[Protondecay123]

Originally Posted by GordMay

Yes Cyclone “FREDDY” was an exceptional storm.
“FREDDY” (Feb 6 - Mar 13/23) generated an ACE of 84.7.
The next highest ACE, of the season, was “DARIAN” (Dec 18 - Dec 31/22), at 42.5.

The highest ever ACE previously ESTIMATED for a single storm in the Eastern or Central Pacific was Hurricane “Fico” in 1978, which generated an ACE of 62.8.

The next two closest Eastern Pacific tropical storms were Hurricane “John” in 1994, with an ACE of 54.0, and Hurricane “Kevin” in 1991, with an ACE of 52.1.
The seasonal record holder, for the Eastern Pacific Ocean hurricane season is 2018, with a total ACE of 318. The second highest ACE, of 295, was recorded in 1992, while the 3rd place is held by the 2015 Eastern/Central Pacific season, with the ACE of 287.

The highest ever ACE index ESTIMATED for a single storm, in the Atlantic basin, is 73.6 for the (4 week) San Ciriaco hurricane in 1899.

The highest ever ACE index CALCULATED for a single storm, in the North Atlantic Basin, was Hurricane Ivan in 2004, with a generated ACE of 70.4. The next two closest North Atlantic tropical storms were Hurricane Irma in 2017, with an ACE of 64.9, and Hurricane Isabel in 2003, with an ACE of 63.3.
And, many of those well-above-average years happened during the La Nina years. During the last 20 years, 2020, 2017, 2010, 2008, 2005, etc. were all during La Nina, or Neutral ENSO years.


The minimum and maximum values of Global ACE per year are respectively 416.2 and 1145.0.
The average value of the Global ACE per year is 730.5.
The contribution of Global ACE from the Eastern and Western Pacific is approximately 56% of the total ACE. The contribution of ACE from the Atlantic Ocean is approximately 13% of the total ACE.

Tropical Weather Theory
Learn what causes hurricanes or typhoons, how dangerous they are, and why they are one of the most destructive formations on Earth.
➥ https://learnweather.com/category/tropical-cyclone/

Great info there Gord. Thanks. The Reuters article i referred to stated that Typhoon Ioke in 2006 was number 2 for estimated ACE at 85. However I couldn’t confirm that with a Google search on my phone. Cheers!

[GordMay]

Originally Posted by Protondecay123

... The Reuters article i referred to stated that Typhoon Ioke in 2006 was number 2 for estimated ACE at 85. However I couldn’t confirm that with a Google search on my phone. Cheers!

Indeed, you're correct.
Super-Typhoon 'Ioke" formed in the Central Pacific, was the record holder for ACE, from a single storm, until "Freddy".


Evidently, “Ioke” was the first Category 5 hurricane to develop in the Central Pacific, since record keeping began in the early 1960s, and it is the most powerful storm to pass through the region since hurricanes Emilia and Gilma, both in July 1994.
Super Typhoon Ioke crossed the International Date Line on August 27, which by convention meant the tropical cyclone was then called a typhoon, instead of a hurricane.

From NOAA’s “Monthly Tropical Cyclones Report for February 2023, published online March 2023":
“... Hurricane/Typhoon Ioke (2006) is (was) the current record holder for ACE from a single storm with about 85 × 104 kt2. Freddy has currently (had) produced about 83 × 104 kt2 and may approach (eventually surpassed) Ioke's record ...”
➥ https://www.ncei.noaa.gov/access/mon...yclones/202302

And from Philip Klotzbach
Meteorologist at CSU specializing in Atlantic basin seasonal hurricane forecasts.
➥ https://twitter.com/philklotzbach

Mar 10
Cyclone #Freddy has now produced 17 #hurricane days (e.g., max sustained winds >=64 kt). That's the most hurricane days by a single hurricane/#typhoon/cyclone globally since Fico (1978-eastern North Pacific).

Mar 9
Latest NOAA ENSO forecast gives a 61% chance of #ElNino for the peak of the Atlantic #hurricane season (August-October). El Nino typically reduces Atlantic hurricane activity via increases in vertical wind shear. Too much shear tears apart hurricanes.

Mar 7
These statistics are based off of Joint Typhoon Warning Center data and will differ slightly from data based off of Regional Specialized Meteorology Centers (RSMC) advisories. In the case of Freddy, that data is from RSMC La Reunion.

Mar 7
#Freddy has now generated ~72 ACE, putting it in 2nd place for most ACE by an individual tropical cyclone since 1980. #Hurricane/#Typhoon Ioke (2006) holds the record with ~85 ACE.

[SailOar]

Originally Posted by GordMay

There are four more relatives in the Atlantic Ocean, Benguela Niño/Niña along the coast of Angola and Namibia, and Dakar Niño/Niña along the east coast of West Africa.

Where is the "east coast of West Africa"?

[grantmc]

Originally Posted by SailOar

Where is the "east coast of West Africa"?

The Indian Ocean?

[GordMay]

Originally Posted by SailOar

Where is the "east coast of West Africa"?

Indeed, I used humorously confusing/misleading language. Sorry.

A coupled warm (cold) SST event, named Dakar Niño (Niña) is located in the Eastern Boundary of the Atlantic Ocean basin, off Senegal, West Aftrica, in the North Atlantic (10° to 26°N).
➥ https://www.nature.com/articles/srep18782

[GordMay]

El Niño* conditions observed and expected to continue

Sea surface temperatures, in the eastern Pacific Ocean, around the equator, are 0.9 ˚Fahrenheit above normal, for this time of year, a warming trend that’s been persistent for the past couple of months.

Data collected by NOAA [1] found that it’s not just surface temperatures measuring above normal. Subsurface ocean temperatures, stretching down to about 300 m below the surface, are also coming in more than 1.0°C above normal, in recent weeks.

This is a swift reversal, from the colder-than-normal sea surface temperatures, that have dominated this part of the ocean, for the past several years. This erstwhile La Niña pattern also had a noticeable impact on the world’s weather patterns.

Given the rapid rate of warming, in this section of the Pacific, and its apparent staying power, forecasters with the U.S. Climate Prediction Center [CPC], expect, with near-certainty [>90% odds] that El Niño will stick around, through at least early 2024.
Forecasters see an 84% chance of this turning into “at least” a moderate El Niño, or stronger; and better-than-even odds of a strong El Niño developing, by the fall or winter months.[2]

[1] “June 2023 ENSO update: El Niño is here” ~ NOAA
➥ https://www.climate.gov/news-feature...ni%C3%B1o-here

[2] “ENSO Diagnostic Discussion” ~ June 8, 2023
Synopsis: El Niño conditions are present and are expected to gradually strengthen into the Northern Hemisphere winter 2023-24.
Discussion ➥ https://www.cpc.ncep.noaa.gov/produc...ensodisc.shtml

* "El Niño conditions" exist when:
A one-month positive sea surface temperature anomaly of 0.5° C or greater is observed in the Niño-3.4 region of the equatorial Pacific Ocean (5° N - 5° S, 120° W - 170° W) and an expectation that the 3-month Oceanic Niño Index (ONI) threshold will be met,
AND
An atmospheric response typically associated with El Niño is observed over the equatorial Pacific Ocean.
ENSO Cycle ➥ https://www.cpc.ncep.noaa.gov/produc...so_cycle.shtml

[GordMay]

Worldwide temperatures briefly exceeded the key warming threshold, [1.5°C*] earlier this month, a hint of things to come.

Researchers at the European Union's Copernicus Climate Change Service [1], said [June 15] that the start of June saw global surface air temperatures rise 1.5 degrees Celsius, above pre-industrial levels, for the first time.
That is the threshold governments said they would try to stay within at a 2015 summit in Paris; beyond which there are major risks for humanity, in terms of climate instability and ecosystem system losses.*

The 11 days, spent at the 1.5-degree threshold, shows how important it is for scientists to keep a close watch on the planet's health, not least because previous spikes above 1.5° have all happened during winter or spring, in the northern hemisphere.

The expectation is, that 2024 will be even warmer than 2023, as the El Niño continues to develop. Typically, El Niño increases global temperatures, in the year after it develops.

* The 1.5° C and 2° C limits, set in the Paris Agreement are targets for the average temperature of the planet, over the twenty or thirty-year periods, typically used to define climate.
IPCC AR6 used 20 years, however the WMO standard reference period is 30 years.

[1] “Tracking breaches of the 1.5° C global warming threshold”

Global-mean surface air temperatures for the first days of June 2023 were the highest in the ERA5 data record for early June by a substantial margin, following a May during which sea-surface temperatures were at unprecedented levels for the time of year [2]. Also in May, the World Meteorological Organization published a report [3], highlighting a 66% likelihood, that the annual average global temperature, in 2023-2027, would be more than 1.5°C above pre-industrial levels, for at least one year ...

➥ https://climate.copernicus.eu/tracki...ming-threshold

[2] “Surface air temperature for May 2023"

The month was the joint second warmest May globally, less than 0.1°C cooler than the warmest May on record. Sea surface temperature and marine air temperature averaged over all ice-free seas were at a record high for May ...

➥ https://climate.copernicus.eu/surfac...ature-may-2023

[3] “Global temperatures set to reach new records in next five years”

Global temperatures are likely to surge to record levels in the next five years, fuelled by heat-trapping greenhouse gases and a naturally occurring El Niño event, according to a new update issued by the World Meteorological Organization (WMO) ...
... A warming El Niño is expected to develop in the coming months, and this will combine with human-induced climate change, to push global temperatures into uncharted territory.
This will have far-reaching repercussions for health, food security, water management and the environment. We need to be prepared ...

➥ https://public.wmo.int/en/media/pres...%20on%20record.

[3b] “WMO Global Annual to Decadal Climate Update (Target years: 2023-2027)”
➥ https://library.wmo.int/doc_num.php?explnum_id=11629

https://library.wmo.int/index.php?lv...splay&id=22272

[GordMay]

"The onset of El Niño will greatly increase the likelihood of breaking temperature records and triggering more extreme heat in many parts of the world and in the ocean," WMO Secretary-General Prof. Petteri Taalas said in a statement [1] Tuesday [July 4].
The effect on global temperatures usually plays out in the year after its development, and so will likely be most apparent in 2024.

The average global temperature in 2022 was about 1.15 °C above the 1850-1900 average, because of the cooling triple-dip La Niña.

The WMO said [1] there is a 90 per cent probability this latest El Niño event will continue through the second half of 2023, and is expected to be at least of "moderate strength."

A WMO report [2] published in May, predicted there is a 98 per cent chance that at least one of next five years, will be the warmest on record, beating the record set in 2016. I think it's fair to say, that, with a with an El Niño that is occurring in a background state of global warming, that extreme weather will become even more extreme.

Canada doesn't tend to see a direct impact, from El Niño, until later in the year [during winter], when the jet streams are more active.

The effects of each El Niño/La Niña event vary depending on the intensity, duration, time of year when it develops, and the interaction with other modes of climate variability.
Not all regions of the world are affected, and even within a region, the impacts can be different. While air temperatures tend to warm. across the tropics. during an El Niño, the impact on rainfall, is region and season specific.

Common regional influences of El Niño include:

El Niño events are typically associated with increased rainfall in parts of southern South America, the southern United States, the Horn of Africa and central Asia.

In contrast, El Niño can also cause severe droughts over Australia, Indonesia, parts of southern Asia, Central America and northern South America

During the Boreal summer, El Niño’s warm water can fuel hurricanes in the central/eastern Pacific Ocean, while it could hinder hurricane formation in the Atlantic Basin.

In Africa: Drier conditions in Southern African and some areas in the Sahel; and wetter conditions in equatorial East Africa during the short rainy season
(October–December).

In Asia Pacific: Lower rainfall in South and South-East Asia; and wetter conditions in the Eastern-Central Pacific islands and Hindu Kush mountain range.

In Latin America: Drier conditions in northern Brazil; and heavy rainfall in Central America, Northern Peru, Ecuador, and the northern and south eastern parts of South America.

[1] “World Meteorological Organization declares onset of El Niño conditions” ~ WMO, July 4/23
Press Release ➥ https://public.wmo.int/en/media/pres...B1o-conditions

[1b] Download this updated technical brief, which explains the role of El Niño, and describes how El Niño affects key determinants of health.
“Health & ENSO” ➥ https://climahealth.info/resource-li...illation-enso/

[2a] “Global temperatures set to reach new records in next five years” ~ WMO, May 2023
Press Release ➥ https://public.wmo.int/en/media/pres...ext-five-years

[2b] “WMO Global Annual to Decadal Climate Update (Target years: 2023-2027)”
➥ https://library.wmo.int/doc_num.php?explnum_id=11629

You might also be interested in:
➥ https://library.wmo.int/index.php?lv...splay&id=22272

In addition to the long-established ENSO Update, WMO now also issues regular Global Seasonal Climate Updates [GSCU], which incorporate influences of the other major climate drivers such as the North Atlantic Oscillation, the Arctic Oscillation and the Indian Ocean Dipole.
GSCUs ➥ https://www.wmolc.org/gscuBoard/list

Latest GSCU [July-August-September 2023] ➥ https://www.wmolc.org/gscuBoard/down...023_update.pdf