Here's a look at the radar from 3-6 p.m., showing why so much rain fell in Middlesex County:
Flooding at a New Jersey Transit underpass tunnel was waist-high.
Flooding at NJ Transit underpass tunnel waist high. Witness says it was to the top earlier. pic.twitter.com/sFQAhFUATJ— CeFaan Kim (@CeFaanKim) July 31, 2016
AJ Ross had more on conditions from South Brunswick:
The rain was so heavy in Princeton Junction, that one viewer said he couldn't leave Princeton Junction station because of flash flooding.
There are also reports of up to 4 inches of rain in the Plainsboro area.
Another video from Plainsboro shows streets completely flooded, with cars unable to move.
As of 5:30 p.m., Jersey Central Power and Light report 2,726 power outages in Morris County, and 1,036 in Somerset County.
Click to watch the 7-day AccuWeather forecast and get the all the weather any time at abc7NY.com/weather.