Between Wednesday 15 and Tuesday 21 January, severe storms affected parts of Victoria and much of eastern NSW and the Australian Capital Territory, bringing short bursts of intense rain, damaging wind gusts and golf- to cricket-ball sized hail to large areas of the state. At different times during the storms, thousands of properties were without power.
During the storms, the New South Wales (NSW) State Emergency Services (SES) received 2,001 requests for assistance with over 1,000 of those calls coming during a storm from 19 to 21 January. The majority of calls related to the removal of fallen trees, the patching of damaged roofs, and sandbagging to protect buildings from localised flooding.
Heavy rain fell in Sydney on 16 January. By the following day, other parts of the state were also affected, with flash flooding in Tingha and Glen Innes in the north of the state.
Two days later, on Saturday 18 January, parts of eastern NSW were hit by severe thunderstorms that caused road closures and flash flooding and cut power to many homes. The heavy downpours provided relief for many parts of NSW stricken by drought and helped firefighters slow the spread of bushfires and build containment lines before increased fire danger expected later that week. By the time the storms had arrived, the 2019-20 bushfire season in NSW had seen 4.9 million hectares of the state devastated by bushfires; 75 fires were still burning and 25 were yet to be contained.
The following day, the Bureau of Meteorology issued a series of severe thunderstorm warnings for Sunday evening for inland NSW. The thunderstorms whipped up strong winds that created huge dust storms carrying topsoil from drought-stricken farms in western NSW. A 300-kilometer wide cloud of red dust descended on the drought-affected towns of Dubbo, Broken Hill, Nyngan and Parkes, turning day into night. A gust of 94 kilometres per hour (km/h) was recorded at Parkes at about 6.30pm while a gust of 107 km/h was recorded at Dubbo at about 7.45pm. The winds and the dust storms had eased by the next day.
In contrast, many towns on the NSW mid-north coast and the northern rivers regions received between 100 millimetres (mm) and 180mm of rainfall from 9.00am to 10.30pm that same day. But in the southern part of the state, high winds saw storms race overhead quickly, resulting in lower rainfall totals.
On Monday, a severe thunderstorm warning was issued at 1.46pm for people in parts of Sydney, the Blue Mountains/Hawkesbury, Maitland/Cessnock, Gosford/Wyong and Wollondilly/Wingecarribee. Almost 20,000 customers lost power after destructive winds, lightning, rain and giant hailstones struck the Sutherland Shire and Sydney’s northern beaches areas, and a freak storm ripped the roof off a city shopping centre.
In the Blue Mountains, two people were struck by lightning – a 16-year-old boy and a 24-year-old man sustained electric shocks and were hospitalised, both in a stable condition.
The following day, the Insurance Council of Australia declared the event a catastrophe, enabling the rapid assessment of storm-related claims. As at 23 March, the estimated cost of damage caused by hailstorms that had struck NSW, the ACT and eastern Melbourne on 19 and 20 January was $1.2 billion from 107,932 lodged claims, more than 60,000 of them for damaged motor vehicles. An estimated 13 per cent (or 14,000) of the claims arose in NSW.