Tornado warning issued for Beaver and Lawrence counties

A tornado warning has been issued for Beaver and Lawrence counties until 5:30 p.m. on Sunday.

The National Weather Service says the warning also includes Columbiana County in Ohio.

Thunderstorm watch in Pittsburgh area

The National Weather Service has issued a severe thunderstorm watch for the Pittsburgh area on Sunday.

The watch is in effect until 9 p.m. on Sunday and includes Allegheny, Armstrong, Beaver, Butler, Clarion, Fayette, Greene, Indiana, Mercer, Washington and Westmoreland counties. The watch extends into Ohio and West Virginia. It includes more than 16 million people, the NWS said. 

"We will be monitoring the tornado threat, and the issuance of a Tornado Watch cannot be ruled out as the event unfolds," NWS Pittsburgh posted to X.

Parts of Mercer, Venango and Butler counties are under a severe thunderstorm warning until 6 p.m.

Weather forecast for Sunday

The timing for the storms is forecast to be from 3 p.m. until 8 p.m. A cold front will move through our area, sliding through Pittsburgh between 5 p.m. and 6 p.m. Strong upper-level winds, along with the front, will provide an environment conducive to a line of storms developing and rolling through, with strong winds being the main concern. 

The Pittsburgh area may see more than one line of storms developing ahead of the front. Of particular concern on Sunday night will be the intersection of multiple lines, with the southernmost line moving faster than the northernmost line. This will create the perfect climate for tornado development. 

Outside of the severe weather window, rain and even some storms will still be possible. KDKA First Alert Meteorologist Ron Smiley's window of severe weather may be too "tight," with severe storm chances potentially sticking around past 8 p.m. for communities south of Interstate 70. 

Highs on Sunday should hit the low 80s, and the low temperature should be hit just before midnight.