Sun in sight? La Niña’s weather model will end in early 2023, BoM predicts

<span>Photo: Bianca de Marchi / EPA</span>“src =”–/YXBwaWQ9aGlnaGxhbmRlcjt3PTk2MDtoPTY0MA–/ -~B/aD02Njc7dz0xMDAwO2FwcGlkPXl0YWNoeW9u/” data-src=”–/YXBwaWQ9aGlnaGxhbmRlcjt3PTk2MDtoPTY0MA – / https: //–~B/aD02Njc7dz0xMDAwO2FwcGlkPXl0YWNoeW9u/https: //</div>
<p><figcaption class=Photography: Bianca de Marchi / EPA

Sunny skies may finally be on the horizon, with modeling from the Bureau of Meteorology suggesting the end of the La Niña weather model early next year.

The long period of rain in many parts of Australia was driven by three consecutive years of La Niña events, which resulted in increased rainfall in northern and eastern Australia.

Related: What is the meaning of La Niña and how will the weather event affect the Australian summer?

The Bureau’s latest climate driver update, released Tuesday, predicts a return to a neutral phase of the El Niño-South Oscillation, a cycle in which winds and sea surface temperatures vary in the eastern tropical Pacific Ocean. Most of the BoM models indicate a “return to neutral ENSO in early 2023”.

The professor.

BoM models show that Pacific Sea surface temperatures will no longer reach La Niña thresholds by February. “It suggests … the event may peak a little earlier than normal December-January [period]McGregor said.

During a La Niña, strong trade winds blow west across the Pacific Ocean. Warm surface waters are pushed towards Asia and the seas north of Australia, causing higher-than-normal rainfall throughout the north-east of the country. The weather event has the reverse effect across the Pacific, with 60% of the United States reported to be in a designated drought zone last week.

In an El Niño, trade winds weaken or reverse, leading to warmer surface waters in the central Pacific and less humidity north of Australia. El Niño events are often associated with severe bushfire seasons, although the black summer bushfires of 2019-20 occurred in a neutral year.

Historically, about half of all years have been classified as ENSO-neutral, a phase that marks the transition between La Niña and El Niño. “There are typically two neutral years for each El Niño and La Niña,” McGregor said.

“Often enough an El Niño will pass [directly] in a La Niña, but typically La Niñas does not go directly to El Niño, “said McGregor.” Looking at the statistics of past events, it suggests that we would more likely have a neutral event next year. “

Until ENSO enters a neutral phase, “unfortunately we expect even more precipitation than normal,” he added.

Extreme La Niña and El Niño events are expected to increase as the planet warms.

The Indian Ocean dipole becomes neutral

Another climatic factor, the Indian Ocean dipole, is also expected to enter a neutral phase. IOD has been negative for the past two years – the first time that two consecutive similar events have occurred since the beginning of reliable records in 1960.

A negative IOD is usually associated with above-average spring rainfall for most of central and eastern Australia. An extremely positive IOD escalated the 2019-20 forest fires.

“The models indicate that negative IOD is likely to persist into late spring before rapidly decaying,” BoM said. “When La Niña and negative IOD conditions combine, the likelihood of above-average rainfall over Australia increases further, particularly for the eastern half of the continent.”

Australia’s climate warmed by around 1.47 ° C between 1910 and 2020. The BoM also noted “a trend towards a higher percentage of precipitation from short-lived, high-intensity rain events, especially in the Northern Australia “.

Leave a Reply

Your email address will not be published. Required fields are marked *