When weather events get severe enough, the National Weather Service will notify the public through different methods. Some will be alerts, while others will trigger your phone or the sirens to jolt you awake.
This week’s night-time storms brought flash flood warnings and watches over much of the Oklahoma City area, but what’s the difference between a flash flood warning and a flash flood watch?
All of the alerts pose some threat and some credence to being wary of the forming weather cycle. But whether they are watches or warnings, each will highlight the severity of the danger.
Here’s what you need to know.
What is a flash flood?
The NWS defines a flash flood as flooding that begins within six hours of the start of the rainfall. Oftentimes, it accumulates by hour three.
Flash floods can be caused by numerous factors, such as a dam or levee break, but they are often triggered by heavy rainfall.
Several factors can increase the severity of flooding, including exposure to drains and piping therein or just the all-around geographic makeup of the affected area.
What is a flash flood warning?
Flash flood warnings are issued by the NWS when a flash flood is imminent or actively occurring. This means that if you are in a flood-prone area, you should move to higher ground.
Also, if you are actively driving, be on the lookout for developing flood waters, which could be destructive to your vehicle.
The NWS stated that flash flooding can develop in as little as minutes or hours.
What is a flood warning?
A flood warning is similar to a flash flood warning in that they’re both issued when a hazardous water event is occurring, but they do have some differences.
The difference between a flash flood and a flood warning is based on how fast the water is collecting. In a flash flood warning, water can collect in a matter of minutes, whereas a flood warning can result from the slow accumulation of water over time.
What is a flood advisory?
Flood advisories are issued when the forecast indicates potential flooding. These alerts are downgraded from a warning, as the NWS says it “is not expected to be severe enough to issue a warning.”
While it may not be severe enough to call a warning, the NWS said the flooding can cause significant inconveniences. If caution is not exercised, they cite situations that could threaten life and/or property.
What is a flood watch?
A flood watch is the least severe of all the alerts. A flood watch notice is issued when conditions are favorable for a flood to occur, but it has not yet been confirmed to happen.
A flood watch is issued when conditions are favorable for flooding, but it is possible that no flooding will occur.
This article originally appeared on Oklahoman: What is a flash flood? Flood warning? What to know about flood alerts
