Severe Weather Warning for Jefferson County

The National Weather Service issued a severe thunderstorm warning and a tornado watch for Arnold and Jefferson County. 

There is a risk for heavy rains, damaging rains and large hail, said an automated phone call at about 4:30 from the CodeRed Weather Warning System.

The thunderstorms can produce golf ball sized hail and possibly tornadoes, said the National Weather System website. 

The NWS said a tornado watch is in effect until 9 p.m. because tornadoes can quickly develop from a severe thunderstorm with 60 mph winds. 

At about 4:30 p.m., the NWS spotted a thunderstorm near Herculaneum which could produce coin-sized hail and 60 mph winds. The storm was moving northeast at 50 mph, the NWS said.