Good question, but I doubt that's why, since there isn't a similar pattern off the SE coast, plus the radar captured similarly heavy rains way offshore of NC without that sawtooth appearance. Supposedly, the max range is 143 miles and those sawtooth patterns are well less than 100 miles from Ft. Dix and other radar sites, but then again, those radar precip maps are showing precip up to 300 miles offshore, so who knows. Maybe it's due to the variability of the banding features to the east of the storm's track in our neck of the woods. Not sure, though...
https://www.wunderground.com/prepare/understanding-radar
