Severe Thunderstorm Warning Issued for Sydney and Wollondilly/Wingecarribee: Flash Flooding and Large Hail Possible

Alert Details

The Australian Government Bureau of Meteorology (BOM) has issued a detailed Severe Thunderstorm Warning (IDN21035) for heavy rainfall and large hailstones. This is a top-priority alert for immediate broadcast, issued at 3:23 pm on Saturday, March 21, 2026.

Affected Areas

The warning specifically covers parts of the Sydney and Wollondilly/Wingecarribee areas. At 3:20 pm, severe thunderstorms were detected near Horsley Park, Oran Park, and Hoxton Park. These storms are forecast to affect the following locations:

• Bringelly by 3:35 pm
• Badgerys Creek, Kellyville, and Rooty Hill by 3:50 pm

What You Should Do

The State Emergency Service (SES) advises residents in the affected areas to take the following precautions:

• Park your car under secure cover and away from trees, powerlines, and drains.
• Secure or put away loose items around your house, yard, and balcony.
• Keep clear of creeks and storm drains.
• Do not walk, ride your bike, or drive through flood water.
• If trapped by flash flooding, seek refuge in the highest available place and call 000 if you require rescue.
• Stay indoors away from windows, and keep children and pets indoors.
• For emergency help in floods and storms, contact the SES at 132 500.

Expected Conditions

Slow-moving severe thunderstorms are currently situated over the western suburbs of Sydney. These storms are likely to produce heavy rainfall that may lead to flash flooding. Additionally, large hailstones are possible as the system moves slowly toward the north.

Timeline

The alert was issued at 3:23 pm on March 21, 2026. The storms were detected at 3:20 pm and are expected to impact specific suburbs between 3:35 pm and 3:50 pm. The next warning update is scheduled to be issued by 3:55 pm.