2 min read · NOAA National Weather Service — JetStream
Rip currents are powerful, channeled currents of water flowing away from shore. They typically extend from the shoreline, through the surf zone, and past the line of breaking waves. Rip currents can occur at any beach with breaking waves, including the Great Lakes.
Anatomy of the rip current.NOAA / National Weather Service
Rip currents most commonly form at low spots or breaks in sandbars and near structures such as groins, jetties, and piers. Rip currents can be very narrow or be hundreds of yards wide. The seaward pull of rip currents also varies: sometimes the rip current ends just beyond the line of breaking waves, but other times, rip currents continue to push hundreds of yards offshore.
Rip currents form as incoming waves (#1 above) push water toward the shoreline (#2 above), which creates an imbalance of water piling up in the surf zone. To stay in balance, the water seeks the path of least resistance back through the surf, which is typically a break in the sandbar (#3 above). This is where the rip current is the strongest. Once the flowing water passes through the narrow gap, it begins to spread out (#4), considerably weakening the velocity and strength of the rip current circulation.
