According to the Australian Government Bureau of Meteorology, the El Niño-Southern Oscillation (ENSO) outlook remains at La Niña WATCH, meaning there is around a 50% chance (double of the normal likelihood) of La Niña forming later in 2022. The current situation is as follows: ENSO indicators are currently at neutral levels. However, some atmospheric indicators, such as the Southern Oscillation Index, continue to show a residual La Niña-like signal. Trade winds have also recently re-strengthened in the western Pacific (more La Niña-like) [1].

Figure 5.7 illustrates the behavior of the standard Southern Oscillation Index (SOI) for the period from July 2021 to July 2022. The SOI has remained positive and high (greater than +7) for the past four months while trending downward in July. Much of the persistent positive SOI signal is due to high pressure systems over Tahiti. While the SOI is an important index that tracks changes in tropical air pressure, a much wider range of atmospheric and oceanic conditions is considered when assessing the status of ENSO. This includes winds, clouds, ocean currents, and both surface and sub-surface ocean temperatures, as well as outlooks for the months ahead.

Another commonly used measure of El Niño is known as the Oceanic Niño Index (ONI). Figure 5.8 shows several ONIs and their locations. Values of the three key NINO indices for June 2022 were: NINO3 −0.3°C, NINO3.4 −0.4°C, and NINO4 −0.3°C (Data for the full month of July is not yet available). It implies that the average sea surface temperature in all three regions is lower than the historical average. Moreover, cool anomalies have weakened, while warm anomalies around northern Australia and to Australia's northeast have strengthened as compared to May. This indicates that La Niña weakened slightly in intensity in June.

Sea surface temperature (SSTs) for June 2022 (Figure 5.9) were generally close to average close to the equator across the Pacific, but SSTs were slightly cooler than average over much of the tropical central and eastern Pacific south of the equator and in some scattered areas north of the equator. Cool anomalies were strongest close to South America. Warm SST anomalies were present over much of the Maritime Continent.

In summary, La Niña continues to be active in the tropical Pacific from April to July but is becoming weaker. La Niña's impact during the Northern Hemisphere summer is generally neutral. It mainly affects winter and spring. In some regions, however, this convention is broken. For example, La Niña was a factor in the hot weather in June in Henan and Hebei, China, and even more so in late July and early August, causing many cities to break historical temperature records. In addition, it caused above-average rainfall over much of northern and eastern Australia during the monitoring period. La Niña events also increased the chances of flooding in Southeast Asia. They also increased the risk of drought and mountain fires in the southwestern United States, and created multiple hurricane, cyclone and monsoon patterns in the Pacific and Atlantic Oceans, as well as triggering weather anomalies in other regions.
During the next monitoring period, La Niña is likely to continue and may bring more flooding to the southern part of China. Brazil is prone to experience droughts during La Niña events. Attention should also be paid to La Niña in the fall and winter (northern hemisphere), which tends to bring cold winters. There is about a 50% chance that La Niña will continue later in 2022, yet the form of La Niña's impact varies by country and region.

Figure 5.7 Monthly SOI-BOM time series from July 2021 to July 2022 

(Source: http://www.bom.gov.au/climate/enso/soi/)

Figure 5.8 Map of NINO Region

(Source: https://www.ncdc.noaa.gov/teleconnections/enso/sst)

Figure 5.9 Monthly temperature anomalies in the tropical Pacific for June 2022

(Source: http://www.bom.gov.au/climate/enso/wrap-up/#tabs=Sea-surface)

Main Sources:

[1]http://www.bom.gov.au/climate/enso/wrap-up/#tabs=Overview