PITTSBURGH, PENNSYLVANIA — A Marginal Risk, Level 1 out of 5, for severe weather stretches from Buffalo and Pittsburgh south through Charlotte and Atlanta today, with a few strong storms possible this afternoon ahead of a weak frontal system, according to an outlook updated at 4:40 AM ET Sunday, August 2. Damaging winds are the primary threat, though flash flooding is also possible thanks to high precipitable water values across the region.
Morning Convection and Low Clouds Limit Instability
Forecasters note that significant morning convection and low clouds will limit the amount of instability available for a widespread severe weather event today. Despite this limiting factor, a few strong to severe storms remain possible during the afternoon hours as the weak frontal system moves through, with damaging winds representing the main concern in any storm that manages to organize.
The darker green corridor, marking the highest concentration of the Marginal Risk, runs from near Buffalo and Cleveland south through Pittsburgh, Charlotte and down into Atlanta, closely tracking the path of the approaching frontal boundary.
Flash Flooding Threat Tied to High Precipitable Water
Beyond the wind threat, forecasters are also flagging the potential for flash flooding today given elevated precipitable water values in place across the region. This moisture-rich environment means any storms that do develop, even without organizing into a widespread severe event, could produce locally heavy rainfall capable of causing flash flooding.
A much broader Marginal Risk footprint, shown in lighter green, extends from Grand Rapids and Detroit through Fort Wayne, Indianapolis, Louisville, Knoxville and Chattanooga, then east through New York City, Philadelphia, Washington D.C., Richmond, Charleston, Savannah and Jacksonville.
Timing for Sunday, August 2
The outlook is valid for Sunday, August 2, with the greatest chance for strong to severe storms and locally heavy rainfall expected during the afternoon hours as the weak frontal system tracks eastward. The corridor from Buffalo and Pittsburgh through Charlotte and Atlanta represents the area with the best combination of instability and threat coverage today…