US: Officials issue flash flood warning in southwestern Pa. until at least 22:30 Aug. 31. Disruptions possible

The US National Weather Service (NWS) has issued a flash flood warning for parts of Allegheny, Washington, and Westmoreland counties in southwestern Pennsylvania on Aug. 31. The warning is scheduled to remain in effect until at least 22:30. It affects Bethel Park, West Mifflin, and Baldwin, among other areas. Officials could amend the warnings for the impacted areas and/or extend them to the surrounding regions on short notice over the coming hours.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rainfall has saturated the soil.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites. Transport, electricity, and telecommunications disruptions are also possible in areas impacted by flooding.