Flooding Rains with the Potential of Severe Weather Thursday

We are tracking a Mesoscale Convective System, that will develop across the Great Lakes region Tomorrow, slides its way Eastward into the state of Pennsylvania by Thursday Morning.

The MCS will reach Western PA by Thursday Morning…likely right around the morning rush hour, before pushing East from there and reaching Eastern PA by the Afternoon hours.

Unlike typical thunderstorms, with a Mesoscale Convective System, on radar you will see a large area of heavy rain and thunderstorms. These will not be hit or miss type storms. More than likely your backyard will see some rainfall Thursday. Just how much rainfall is the question.

The STORM PREDICTION CENTER has stated in their forecast the MAIN THREATS for Thursday involve damaging winds and hail. As it stands right now the further South you go in PA, the better chance to see Severe Weather activity. We will have to watch for future trends to see if the threat for an isolated tornado increases, but the threat is very low currently.

Area A – The STORM PREDICTION CENTER has placed this region under a SLIGHT RISK for Severe Weather. Main threats: Damaging winds and hail.

Area B – The STORM PREDICTION CENTER has placed this region under a MARGINAL RISK for Severe Weather. Although the threat is lower than those in Area A, the main threats will still feature damaging winds and hail.

Area C – This area will just see plain old thunderstorms with some heavy rain. No real severe threat in this region.

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So how much rainfall are we talking? Potentially enough for flash flooding in areas throughout PA.

Area A – Highest risk for flooding rains. Most of the rainfall will fall in a 6 hour period. Early estimates show anywhere between 1 and 3 inches of rainfall.

Area B – Moderate risk for flooding rains. Early estimates show up to 2 inches of rain in a 6 hour period.

Area C – Low risk for flooding rains. Most guidance shows less than an inch of rainfall for this region.

*Please note, if your backyard gets hit by a severe storm, there is the chance for these numbers to double in very localized cases.

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Josh Adams is the founder and lead forecaster of Pennsylvania Weather Action, a regional forecasting site he launched in 2015. With over a decade of experience analyzing weather patterns across Pennsylvania, his forecasts have reached millions of readers throughout the state. Josh specializes in Pennsylvania’s complex microclimates and terrain-driven weather patterns, providing detailed coverage of severe thunderstorms, winter storms, and flooding events. His forecasting focuses on delivering precise, timely information to help Pennsylvanians stay informed and prepared during impactful weather. Last Updated: March 10, 2026