UPDATE (9:30 p.m.)The National Weather Service has put a tornado watch and flash flood warning in effect until 2 a.m. for York and surrounding counties. Doppler radar has recently detected severe thunderstorms capable of producing winds in excess of 60 mph. In York County, they could affect Weigelstown and neighboring vicinity, according to the service.
National Weather Service forecasters said about 1 inch of rain accumulation was reported by 9:30 p.m. in Shrewsbury, as well as wind damage around York county and the general area. No tornadoes had been reported. York County emergency services have responded to several calls for clearing road debris.
Previous updates:The National Weather Service has issued a flash flood watch for York County until 2 a.m. Saturday, as several rounds of heavy showers and thunderstorms are expected throughout the night. The area possibly could get up to three inches of rain. A tornado watch remains in effect for York County until 9 p.m.
At 4 p.m., radar indicated a severe thunderstorm capable of producing a tornado. Locations in the warning area include Shrewsbury, Glen Rock, Stewartstown and Brogue. York County was not in the original tornado watch.
Calling this week a "notorious weather period" for parts of Pennsylvania, the National Weather Service in State College is expecting severe thunderstorms with a chance of hail and tornadoes in York County Friday afternoon and evening.
Meterologist Barry Lambert said York is expected to get as much as 4 inches of rain in some areas, with at least 1 or 2 inches across most of the area. There's a potential for "intense rainfall" and flooding as tributaries are overwhelmed, he said.
The storm is forecast to enter the area around 4 p.m. and remain until about 10 p.m., he said. There's an isolated tornado threat along the boundary of the storm, which starts around Indiana, Pa. and stretches through York County, Lambert said.
Winds will be between 10 and 20 miles per hour with strong downbursts throughout the storm, he said. Residents are advised to stay inside and remain connected to a source of updates about the storm.
Lambert said late May and early June is a "notorious weather period" for central and southern Pennsylvania because the sun is moving into an angle that can produce enough heat to create a volatile relationship with lingering cool winter air over Canada, he said.
Examples include the only Category 5 tornado in state history being logged on May 31, 1985. The first Johnstown flood that killed 2,200 people was May 31, 1889, and more than 18 tornadoes were confirmed on June 2, 1998, he said.