Lala Approaching Hawaii; Flash Flooding Risks; Excessive Heat

Lala, may become a hurricane, is expected to impact Hawaii this weekend. Heavy rainfall, strong winds, dangerous surf and localized flooding are expected. Heavy rainfall and flash flooding concerns from the mid-Mississippi Valley, Ohio Valley into the central Appalachians continues, with the threat shifting toward the mid-Atlantic later this weekend. Record heat continues for areas of the South. Read More >

Definitions of Flood and Flash Flood

Flood: An overflow of water onto normally dry land. The inundation of a normally dry area caused by rising water in an existing waterway, such as a river, stream, or drainage ditch. Ponding of water at or near the point where the rain fell. Flooding is a longer term event than flash flooding: it may last days or weeks.

Flash flood: A flood caused by heavy or excessive rainfall in a short period of time, generally less than 6 hours. Flash floods are usually characterized by raging torrents after heavy rains that rip through river beds, urban streets, or mountain canyons sweeping everything before them. They can occur within minutes or a few hours of excessive rainfall. They can also occur even if no rain has fallen, for instance after a levee or dam has failed, or after a sudden release of water by a debris or ice jam.

Local Radar