It doesn't ride the rails but this weather train means serious business. These waves of storms can quickly trigger flash flooding.

A train of storms, or training for short, occurs when a front becomes nearly stationary and the upper-level steering flow becomes nearly parallel to the front. If the atmosphere remains unstable due to a feed of moisture from an ocean or the Gulf of Mexico, storms will continue to develop along the front and move over the same spots as previous storms, bringing wave of downpours to the same spots, sometimes over several days.

Rainfall totals in excess of 5 inches are likely if this pattern develops, triggering flooding along rivers and creeks. Flash flooding can develop if the rainfall falls quickly.

Here are some safety tips if a flood threatens:

Meteorologists call this training because the storms line up and move over the same areas on an invisible railroad. The WeatherRadar is a great way to spot these events by animating it and watching storms roll over the same area over and over again.