Update, 4:30 PM: As of 4 PM, the only storms that have popped up were in the Poconos, with those storms moving into North Jersey and are poised to move towards New York City in the next 90 minutes. Another storm cell is trying to fire as of 4:30 PM in Somerset County -- as of the time of this update it's still in the formative stage. Storm activity may try to pop out to our west over the next couple of hours as we have a pretty impressive amount of instability, heat, and humidity to work with. However, the "trigger" is pretty weak in the atmosphere and that's inhibiting a more widespread development of thunder across the region. There could be a couple of showers or storms that pop up to our west and move east and east-southeast over the next few hours.
The potential of a few scattered severe storms in parts of the region this afternoon and evening has lead the Storm Prediction Center to issue a Severe Thunderstorm Watch until 8 PM for counties north of Philadelphia and north of I-195 in New Jersey. This watch does NOT include the city, Delco, South Jersey, or areas impacted by Friday night's storms.
As of 1:40 PM, radar locally is quiet and shows no thunderstorm activity. A few storms are around up in New York and Connecticut, moving east. Any thunderstorm development will occur later on this afternoon, generally in a scattered or isolated fashion. Given the pretty high levels of heat and humidity in place throughout the atmosphere, any storm can be severe and produce gusty winds, large hail, as well as localized heavy downpours.
Storm movement will be east-southeast or east, with the best chances of storm develop occurring to the north and northeast later on. This doesn't mean that Philly and south won't get in on any thunderstorms later on but the chances of any storm activity is better north than south (at least as of now).
More: Current Weather Radar