“Rain Bomb” Strikes Central East Coast of Australia

Highlight: “Rain bomb” strikes East Coast of Australia. Brisbane hardest hit. Heavy rains shifting southward.

Fig. 1: Satellite view of the “Rain Bomb” now just-offshore the central East Coast of Australia.

Discussion: A “perfect storm” emerged just-off Brisbane on the central East Coast of Australia yesterday (Fig. 1). A small but intense area of upper-level difluence (Fig. 2) above an equally intense area of low-level conflue4nce (Fig. 3) created a “chimney effect” to drive a super convective storm which extended inland unloading record rainfall for Brisbane and surrounding communities. Widespread damage and fatalities are reported due to the “rain bomb”. ECM indicates the “rain bomb” drifts south this week with the western edge of excessive rainfall continuing on the New South Wales Coast (Fig. 4). Eastern Australia continues a historic wet warm season (Fig. 5) due to presence of La Nina and more specifically a persistent upper trough located over south-central/southeast Australia (Fig. 6).

Fig. 2-3: Areas of maximum upper-level divergence and low-level convergence combine to drive a “rain bomb” on the Australia East Coast.

Fig. 4: ECMWF 114-hour rainfall forecast for Australia.

Fig. 5-6: Nov. 1, 2021 to Feb. 25, 2022 anomalous rainfall and upper air pattern across Australia.