Weather

How much rain will it take to cause flash flooding this weekend?

High water will be a concern heading into the weekend after flash flooding Wednesday night across parts of the area.

Rain the next couple of days will not come as fast and furious as it did Wednesday evening, but with the ground nearly saturated in many areas from Allegheny and Westmoreland counties on south, it won't take a ton of rain to create flooding issues.

STORY: Rain continuing through weekend

Most areas in Allegheny, Westmoreland, Washington, Fayette and Greene counties would only need 1.3 to 1.4 inches of rain in less than six hours to cause flash flooding. In a 12-hour period, those numbers go up to 1.5 to 1.8 inches.

These are called flash flood guidance numbers from the National Weather Service's hydrology department. When radar estimated rainfall amounts reach these numbers, flash flood warnings are generally issued.

With repeated rounds of rain through Sunday, a few areas could see up to 2 inches of rain total through the weekend.

Those living in low-lying and flood-prone areas will need to keep aware in the event of repeated rounds of moderate to heavy rain over a short period of time.

Severe Weather Team 11
 
Stephen Cropper
 
Scott Harbaugh
 
Kevin Benson
 
Danielle Dozier
 
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