Straighter, smoother streams flow more violently than those that meander due to a reduction in friction. Areas with steeper terrain can see water accelerate downhill at a much faster rate causing a more destructive flash flood than flatter, open areas.

A flash flood warning is in effect until 9 a.m. for Boston and several communities south of the city, including Brockton, Quincy, and Randolph, officials said Thursday morning. The National Weather Service also issued a flood watch that will remain in effect until 4 p.m. for Rhode Island and eastern portions of Massachusetts and Connecticut.

Flash flooding has been in the spotlight in the last week, with several record breaking flood events occurring nearly back-to-back across the country. CNN’s Tyler Ory explains why they’re becoming more intense .

A "considerable" flash flood warning has been issued in Boston as heavy, life-threatening rain pounds the city and areas to the south.

Recent flash flooding in Texas​, New Mexico​ and North Carolina​ is highlighting the extreme danger of these natural disasters and the need to be prepared.

Along a similar vein, conspiracy theories maligning Doppler weather radars as “weather weapons” have heightened in the wake of flash floods in central Texas. Forecasters use the radar system to detect precipitation, and now have to worry about vigilantes vandalizing them at times when people rely on those forecasts to stay safe.

For the third straight year on this date, residents in Caledonia County are dealing with damage from flash flooding. ABC22's Roy Santa Croce is on the scene in Lyndon.

Flash flooding from heavy rain killed at least three people and prompted dozens of rescues in the Ruidoso area of southern New Mexico, officials said — the same area devastated by wildfires last year.