Test flash flood warning to air in Juneau Sept. 23 for Salmon Creek Dam

Juneau's weather radios and broadcast stations will sound a "Flash Flood Warning" on Wednesday, Sept. 23 — but there won't be any flood. It's a test.

The National Weather Service and Alaska Electric Light & Power are running a live test of the Salmon Creek Dam alert system between 10 a.m. and noon, sending the message over NOAA weather radios and the Emergency Alert System that interrupts TV and radio. It will set off weather radios the way a real warning would.

The point is to make clear it's only a drill. "The audio message will use the phrase Flash Flood Warning but will state that the message is only a test," said Nicole Ferrin, a meteorologist at the Juneau weather office, adding that the word "test" will be repeated several times. The alert will not go to cellphones.

One thing the announcement doesn't address: whether the dam's evacuation siren — a separate system — will sound during the drill. In a real emergency, the utility says, that siren means to leave the floodplain immediately.

Bad weather in Juneau that morning could push the test to another day.