Criteria for a flood warning and flash flood warning
The National Weather Service (NWS) is the official U.S. government agency charged with issuing weather watches, warnings, and advisories and is the source used by iAlert.com. Below is the criteria for a flooding used by NWS forecasters when issuing flood warnings across the country….
FLOOD WARNING: A Flood Warning is issued when inundation of a normally dry area near a stream or other watercourse is expected, OR unusually severe ponding of water expected. Flooding of rivers or streams doesn’t always required rain to be overhead for your area to flood. Heavy rain upstream will make its way downstream causing flooding.
FLASH FLOOD WARNING: A Flash Flood Warning will be issued after few hours of locally heavy rainfall, a dam or levee failure, or water released from an ice jam rapidly flooding nearby land. Although flash flooding typically occurs in hilly or mountainous areas flash flooding can happen anywhere
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