Source: Bureau of Meteorology

Issued at 10:09 pm Sunday, 12 November 2017.

At 10:00pm radar imagery showed a thunderstorm just off the Perth coast near Swanbourne, moving slowly up the coast. This thunderstorm is likely to be severe, and could produce heavy rainfall that may lead to flash flooding and large hailstones in the warning area over the next hour if it moves over land.

The Department of Fire and Emergency Services advises that people should:
* If outside find safe shelter away from trees, power lines, storm water drains and streams.
* Close your curtains and blinds, and stay inside away from windows.
* Unplug electrical appliances and do not use land line telephones if there is lightning.
* If there is flooding, create your own sandbags by using pillow cases filled with sand and place them around doorways to protect your home.
* If boating, swimming or surfing leave the water.
* Do not drive into water of unknown depth and current.
* Slow down and turn your headlights on.
* Be alert and watch for hazards on the road such as fallen power lines and loose debris.
* If it is raining heavily and you cannot see, pull over and park with your hazard lights on until the rain clears.