Essential Intelligence

What Exactly Is a Flash Flood?

It's a term that gets used a lot around these parts.

By Megan McDonald June 12, 2024

Flooding at Triangle Ranch after Hurricane Ian.
Flooding at Triangle Ranch after Hurricane Ian.

As Sarasota experiences record rainfall after a nearly year-long drought, meteorologists are warning locals to beware of flash floods. It's a term that gets used a lot around here, specifically during hurricane season and when we have unexpected severe weather

But what exactly is a flash flood?

According to the National Weather Service, a flash flood is "flooding that begins within six hours, and often within three hours, of heavy rainfall," although they can also occur because of mudslides or dam or levee breaks. Topography, vegetation, soil type and soil water content all play a role in determining how quickly an area floods, too. In urban settings, sudden rainfall also causes flash floods, particularly in low-lying areas where water can quickly run off.

The danger of flash flooding is right there in the name: it can happen so quickly that people get caught off-guard, and situations can quickly devolve if water rises and traps them in their home or drivers have to move through high waters while traveling. 

How to Stay Safe During a Flash Flood Situation

  • Don't drive through flooded roads, especially at night, when't is harder to gauge water depth. You could drive into a washout, in which water has washed away a piece of the road, or the roadway may have collapsed due to erosion. 
  • Do abandon your vehicle if it stalls due to waterlogging. Immediately seek higher ground. Six inches of water will reach the bottom of most passenger cars causing loss of control and possible stalling, and a foot of water will float many vehicles. When in doubt, turn around.
  • Do be familiar with your area and it's topography. If you know where higher ground is located, you can head there in case of an emergency. 
  • Do stay tuned to local government social media pages or call 311 for the latest guidance on dangerous weather.

Source: National Weather Service

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