The southeastern part of York County is under a severe thunderstorm warning until 5 p.m.
A storm capable of prouducing gusty winds in excess of 60 mph and hail the size of a quarter is moving into the area, the weather service says.
The National Weather Service has issued a severe thunderstorm watch for York County and much of the surrounding area.
The watch is in effect until 8 p.m.
According to the weather service forecast, there is a 60 percent chance of showers and thunderstorms today, mainly between 3 and 8 p.m., and some storms could be severe.
Today's high will be near 79, with temperatures dropping to about 51 overnight, the forecast says.