A rather vigorous system will approach from the west on Fourth of July bringing with it rain, heavy at times.
Rain should move into the area Monday afternoon, but won't become steady until after nightfall. The best bet for uninterrupted Fourth of July fireworks will be east. If we do see any heavy downpours of rain, they will happen early Tuesday morning.
The rain should clear out from west to east Tuesday morning and early afternoon. When it's all said and done, northern parts of the coverage area will likely have the most rain, with as much as 2 inches likely. Central New Jersey totals should stay under and inch, with even less rain in south Jersey and Delmarva.
These rain totals are in no way set in stone, and will most likely change. There is still plenty of speculation and model disagreement as to where exactly this thing will track. The trend has been north, so I'm going with the heaviest rains being north of the Philadelphia area. However, the NWS predicts that the heaviest rains will fall south of Philadelphia.
I'll have an updated map tomorrow. In the meantime, be sure to check out my twitter @conweather and follow!