While we're not forecasting widespread or epic soakings throughout the Delaware Valley today, any scattered thunderstorms that do develop won't be in any hurry to move as steering in the low and mid levels is pretty weak. Knowing that there's not a lot of directional kick today, storms that fire up later on today will have the tendency to produce heavy rainfall in some locations.
The potential does exist for some localized flooding in parts of the region later today. Flash flood guidance for one hour rainfall is rather low -- around 1.2" across the northern and western suburban counties, even less than that over Central and North Jersey, according to the National Weather Service. The only places that have "respectable" flood thresholds are the Shore counties to our east and southeast, plus Camden and Gloucester Counties over the river in New Jersey.
While thunderstorm development over the region today should be scattered or in scattered lines, not everyone gets wet. Modeling varies still on placement as the NAM keeps the bulk of thunder threat north of the city while the GFS places more thunder activity south. The Euro gives everyone scattered storms in being fair and balanced to the whole of the region. With the weak front the only real focal point and the atmosphere relatively rich in moisture, storms may be more apt to fire near the front later on today...which would be to our north.
Regardless, the threat for scattered thunder through the region does exist and any storms that do fire have the threat to produce some heavy rainfall and perhaps gusty winds. Odds don't favor much severe weather but a rogue severe storm or two is possible later on.