National Weather Service Issues Severe Thunderstorm Watch

A severe thunderstorm watch is in effect until 4 p.m. Wednesday as a flood advisory for the Ohio River continues, according to the National Weather Service.

The thunderstorm watch area includes Allegheny, Armstrong, Beaver, Butler, Fayette, Greene, Indiana, Washington and Westmoreland counties.

A watch is issued when conditions are favorable for the development of severe thunderstorms in and close to the watch area. 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. 

A flood advisory also is in effect for the Ohio River at Pittsburgh. The river at the Point is forecast to rise above 18 feet by Thursday evening, which will flood the Monongahela parking wharf.

The National Weather Service forecasts the river to crest around 18.5 feet by early Friday morning, then fall below 18 feet by Friday evening.

Here is the NWS forecast, as of Wednesday at 9:15 a.m., for the Dormont (15216) and Brookline (15226) zip codes:

Wednesday: Windy, with showers and thunderstorms likely. A few storms may be severe. High 64F. Winds S at 20 to 30 mph.

Wednesday Night: Windy with possible snow showers later in the evening. Low near 30F.

Thursday: Windy with snow throughout the day. High near 30F, with chance of snow at 30 percent. Winds could gust at more than 40 mph.

Thursday Night: A 50-percent chance of snow showers, resulting in a one-inch accumulation of snow. Low near 18F.

Friday: High of 21F with a 30-percent chance of snow. Low of 16F later in the evening.

Saturday: Temperature of 26F, with 30-percent chance of snow throughout the day.

Follow Dormont-Brookline Patch on Facebook and Twitter. For more news, sign up for our email Newsletter.