Flash Floods

NWS Cleveland

Floods and Flash Floods

Floods and flash floods are a threat to Ohio. Deaths from flooding are usually due to negligence or not knowing what to do. Our severe weather preparedness plans should include ways to safeguard ourselves from flood threats.

What is the difference between a flood and a flash flood?

Flash flooding is a result of heavy localized rainfall such as that from slow moving intense thunderstorms. Flash floods often result from small creeks and streams overflowing during heavy rainfall. These floods often become raging torrents of water which rip through river beds, city streets, coastal sections and valleys or canyons, sweeping everything with them. Flash Flooding usually occurs within 6 hours of a heavy rain event.

On the other hand, the more long term "flood" is a natural and inevitable part of life along our country's rivers. These floods occur seasonally with general rains or torrential rains associated with tropical storms, that later drain in river basins and fill them with an over- abundance of water. General flooding occurs in urban areas and areas with poor drainage after heavy rain.


  1. In hilly terrain, flash floods can strike with little or no advance warning. Distant rain may be channeled into gullies and ravines, turning a quiet stream into a rampaging torrent in minutes. Never camp on low ground next to streams since a flash flood can catch you while you're asleep.
  2. Do not cross flowing stream on foot where water is above your ankles.
  3. If you are driving, dont try to cross water-filled areas of unknown depths. If your vehicle stalls, abandon it immediately and go to higher ground. Rapidly rising water may sweep the vehicle and its occupants away. Many deaths have been caused by attempts to move stalled vehicles.
  4. Be especially cautious at night. It's harder to recognize water danger then.
  5. Don't try to outrace a flood on foot. If you see or hear it coming, move to higher ground immediately.
  6. Be familiar with the land features where you live, work, and play. It may be in a low area , near a drainage ditch or small stream, or below a dam. Be prepared!
  7. Stay tuned to NOAA Weather Radio for the latest statements, watches and warnings concerning heavy rain and flash flooding in your area, report it to the National Weather Service.

The National Weather Service will issue a Flash Flood Watch when heavy rains may result in flash flooding in a specific area. In this case you should be alert and prepare for the possibility of a flood emergency which will require immediate action. A Flash Flood Warning will be issued when flash flooding is occurring or is imminent in a specified area. If your locale is placed under a warning, you should move to safe ground immediately.

For what to do on a Typical Severe Weather DayLook Here

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