Flood alerts defined

Jonathan Brazzell - NWS Late Charles

Service Hydrologist

Areal Flood warnings - are used mainly after heavy rainfall events to indicate that creeks and streams will continue to flood beyond six hours after the flash flood event. They can also be used at gaged streams where there is no river forecast point available.

Flash Flood warnings - Are used for flooding that is or expected to occur within six hours of the event that caused the flooding. In most cases it is heavy rainfall that causes this, but could be dam or levee failures as well. Flash Flood Warnings have different categories. Base Category is pretty common and does not trigger cell phone alerts. This is more nuisance type flooding that may cause some inconvenience and secondary road closures.

Flash Flood Warning Considerable tag is used when property damage is expected or primary roads will be closed and could pose a threat to life. This will trigger cell phone alerts.

Flash Flood Warning Catastrophic tag is used when widespread threat to life and property is expected. This will usually require a large rescue response. The last time we issued this was for the Kirbyville event on April 10th. Cell phones will also be alerted for this one as well.

Flood Watches just mean that conditions are favorable for flooding within the next 48 hours.

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Jonathan Brazzell

Service Hydrologist