This is a forecast map for June 28 2015–that trough you are seeing over the East Coast is more like a winter time pattern than mid-summer.. It’s strong for this time of year. If it happens to occur like that, there may be some flooding over Pennsylvania, New Jersey, and other parts of the East Coast. 

My forecast area is in the trough location.. Current forecast for the time period in question: High temperatures in the 60s with rain.. That is more like April of October.. Not the week of the Fourth of July.