A trough of low pressure began tracking across South Australia on 27 October, producing gusty thunderstorms. Further south, a developing low-pressure system drove thunderstorms across the state overnight and during the morning of 28 October. In what the Bureau of Meteorology described as ‘waves of thunderstorms’, large hail with thunderstorms initially impacted the Eyre Peninsula and moved across Yorke Peninsula, then over the northern suburbs of Adelaide and the Barossa Valley in the morning of 28 October and in the Murraylands, Riverland and southeast of the Northeast Pastoral in the afternoon.

Strong wind gusts of up to 124 km/h were reported with a thunderstorm at Wappika (west-north-west of Loxton) at 4.10pm. 98 km/h winds with a thunderstorm were reported at Loxton at 4.40pm. The system brought wind, hail, lightning, and heavy rainfall resulting in minor flash flooding. Hail within the stronger cells was generally 1-3 cm, with local reports of 3-5 cm hail over the northern Adelaide area, focussed on the Elizabeth/Craigmore area.

Significant impacts were observed after multiple fronts crossed the state with reports of roof and skylight damage due to large hailstones, and property damage due to water ingress with many reports of collapsed ceilings. Areas of thick raised dust with reduced visibility also occurred over the Pastoral and Flinders districts and parts of the northern agricultural area. The City of Playford and Adelaide Plains councils reported horticulture and infrastructure damage. There were power outages and numerous school closures in the Adelaide northern suburbs due to the extreme weather.

Tornadic activity was reported in Waikerie, resulting in significant damage to roofs of homes and businesses, trees down, structural damage and downed powerlines. As is common with large hail, there were many vehicles damaged, including some vehicles belonging to volunteers which were parked at South Australia State Emergency Service (SASES) units while volunteers attended requests for assistance (RFA). The multi-agency approach to the response was excellent and unprecedented, particularly in the Riverland and Adelaide northern suburbs. SASES, Country Fire Service (CFS) and South Australia Metropolitan Fire Services (SAMFS) responded to RFAs with SASES undertaking many of the temporary repairs on roofs and technical tree down jobs and SAMFS providing strike teams on an ongoing basis until the RFAs were resolved. The CFS also attended RFAs, provided operational support and undertook reconnaissance.

The types of requests for assistance for large hail tend to take longer to attend to, and require specialist skills, compared to some other events. Crews were often required to assemble safe work systems prior to accessing roofs and then undertaking repairs. It took several days to resolve the many outstanding RFAs, particularly in the northern Adelaide and Riverland districts of the state. Over 1,300 requests for assistance were received for this event.

Provision of operational consumables were provided at the Salisbury SASES which was central to a significant proportion of RFAs. This also enabled centralised provision of catering and logistics which was provided by the Paralowie Lions Club. There were many complexities involved in this event due to its fast-impacting nature, which caused damage to many homes and buildings. There were also several geographic areas
impacted in a short timeframe.

The SASES units in impacted areas, particularly in Adelaide’s northern suburbs, continued to receive calls for assistance in the days and weeks after the incident when rain occurred. There were additional weather events that impacted homes in subsequent weeks. The COVID-19 situation and lack of resources in the building sector meant that some repairs were taking a very long time resulting in many re-attends. This impacted on the fatigue and morale of volunteers.