Tropical cyclones, including the rare southern hemisphere event Cyclone Raquel, have caused the current El Nino to strengthen.

The cyclones forced a strong reversal of trade winds near the equator, which will lead to rising temperatures in the tropical Pacific Ocean, according to the Bureau of Meteorology.

Cyclone Raquel was the first July cyclone recorded in Queensland, and only the second in Australia following a system that formed off WA in 1996.

“All international climate models surveyed… suggest El Nino will persist until at least the end of [this year],” the bureau’s latest update says.

“Models also indicate that further warming is likely.”

El Nino is associated with drought over eastern Australia and higher temperatures in the south, leading to an increased bushfire risk in many areas.

However, the strength of El Nino does not always determine the strength of its effect.

Other factors, such as the state of the Indian Ocean, also have a major influence on Australia’s climate. The Indian Ocean Dipole (IOD) is currently neutral, but three out of five international models suggest a positive IOD is likely during spring.

A positive IOD usually leads to reduced rainfall over parts of southern and central Australia, exacerbating bushfire risk.