UPDATE: Look Out for Weather—Severe Thunderstorm Watch Remains in Effect

SECOND UPDATE: The severe thunderstorm watch has been extended to midnight for Allegheny County, the National Weather Service states.

The watch area also includes Beaver, Fayette, Westmoreland, Washington and Greene counties.

A severe thunderstorm watch is issued by the National Weather Service when conditions are favorable for the development of severe thunderstorms in and close to the watch area, according to the service's website.

The more serious "warning" is issued when a storm is indicated on radar or by a spotter.

"A severe thunderstorm by definition is a thunderstorm that produces one inch hail or larger in diameter and/or winds equal or exceed 58 miles an hour," the website states. 

Earlier story:

UPDATE: A severe thunderstorm watch remains in effect for western Pennsylvania until 7 p.m. Saturday, according to the National Weather Service.

The watch area also covers east central Ohio and northern West Virginia.

A severe thunderstorm warning was issued at 5:27 p.m. for south central Allegheny County, east central Washington County and northeastern Fayette County. It expires at 6:15 p.m.

National Weather Service Doppler Radar indicated a severe thunderstorm near Elizabeth Boro at 5:24 p.m., moving southeast at 25 mph.

Earlier in the afternoon, the weather service issued a warning for a severe thunderstorm capable of producing quarter-size hail and damaging winds in excess of 60 mph.

At 4:27 p.m., the storm was located near Leechburg, moving east at 30 mph, th National Weather Service reported.

The National Weather Service asks residents to report hail, strong winds or wind damage to the service by calling toll-free at 1-877-633-6772.

A severe thunderstorm watch is issued by the National Weather Service when conditions are favorable for the development of severe thunderstorms in and close to the watch area, according to the service's website.

The more serious "warning" is issued when a storm is indicated on radar or by a spotter.

"A severe thunderstorm by definition is a thunderstorm that produces one inch hail or larger in diameter and/or winds equal or exceed 58 miles an hour," the website states. 

Saturday's earlier story:

A severe thunderstorm warning was issued at 3:53 p.m. Saturday by the National Weather Service.

Gibsonia is included in the warning area.

"At 3:51 p.m. EDT, National Weather Service Doppler Radar indicated a severe thunderstorm capable of producing quarter-size hail ... and damaging winds in excess of 60 mph.

"This storm was located near Mars, moving east at 30 mph," according to the weather service website.

The warning is in effect until 4:45 p.m.

The warning area includes northeastern Allegheny County, southwestern Armstrong County, southeastern Butler County and northwestern Westmoreland County.

The storm is also expected to impact the Pennsylvania Turnpike between Mile Markers 36 and 55.

Check back with Patch for updates.