Early on 21 May, Herbie made landfall in Shark Bay before losing its identity the following day over the Great Australian Bight.

[1] Several hours after, the Joint Typhoon Warning Center (JTWC) classified the system as Tropical Depression 21S, having attained winds of 45 km/h (30 mph 1-minute sustained).

[2] Following slight development, the system intensified into a Category 1 cyclone and was given the name Herbie by the Australian Bureau of Meteorology early on 18 May.

[1][3] Several hours after being named, the storm attained its initial peak intensity with winds of 75 km/h (45 mph 10-minute sustained) and a barometric pressure of 990 hPa (mbar).

[3] Around the same time, the JTWC upgraded the system to a tropical storm, estimating the cyclone to have attained peak winds of 65 km/h (40 mph 1-minute sustained).

[1] Several hours after the relocation, the JTWC downgraded Herbie to a tropical depression as the system's movement began to accelerate towards the southeast.

Early on 21 May, the center of Herbie made landfall in Shark Bay with wind gusts up to 120 km/h (75 mph) and a pressure of 980 hPa (mbar).

Due to the rapid movement of the storm, it reached the Great Australian Bight while retaining tropical characteristics despite its low-latitude.

[1] In Denham, a storm surge of 2 m (6.6 ft) broke the town's retaining wall and flooded low-lying areas along the shore.