Current surface analysis indicates a cold front will be sweeping south and east into the area highlighted, bringing what the Storm Prediction Center calls 'supercells and/or severe multicell line segments' to the region.
Considering the area highlighted is within warm temperatures but not so high humidities, these storms should not be incredibly rainy, so flash flooding is not anticipated in most areas. However, heavy rainfall in an area cannot be ruled out.
When the SPC is talking about these 'severe multicell line segments', they are discussing bowing segments of storms.
SPC's WRF-NMM model is projecting that a line of strong storms will ignite in the region and likely produce some severe activity in the region.
same WRF-NMM run off a different machine tells that the storms should be based farther west. Considering that the first image is from what I consider the 'operational' forecast, and it seems to be in line with the SPC, I will go with that solution.