Explaining The Wet Spring Pattern Across Australia

Highlight: The wet Australian spring caused by “warm blobs”!

Fig. 1: The SEP/OCT/NOV 2021 upper air pattern across Australia and features leading to the wettest spring since 2010.

Fig. 2: Global SSTA for November 2021 identifying “warm blobs” affecting the Australia climate pattern.

Discussion: The wettest spring since 2010 has just completed across Australia. Spring was an all-time top 10 wet spring in Australia’s climate record. Developing La Nina will be blamed for the wet pattern and certainly contributed. In fact, according to multivariate ENSO index (MEI) the La Nina climate pattern emerging in 2020 never ended in 2021. However, other factors contributed (heavily) to the wet pattern across Australia during their just-ended meteorological spring season. A large semi-permanent region of warm SSTA east of Australia and particularly strong just east of New Zealand is in-place due to a semi-permanent amplified upper-level high-pressure ridge. Similarly, an emerging “warm blob” of SSTA in the South Indian Ocean is well-correlated with another emerging upper-level high-pressure ridge. In-between the two ridge areas? A super wet upper-level low-pressure trough over Australia!