"Rainfall of this intensity can cause flash flooding, especially around rivers and streams, and potentially lead to slips. If you're in the car it can reduce visibility a lot so it can make driving quite dangerous."
A Fire Service spokesman said there had not been an influx of weather-related calls this afternoon.
Civil Defence has advised that people in the affected areas take shelter indoors, move their vehicles away from any trees, secure any loose objects around their property, check that drains and gutters are clear and be ready to slow down or stop if driving.
After the storms pass, people should still take care and watch out for fallen branches, power lines and other objects.