yellow alert

American  

noun

1. (in military or civilian defense) the first alert given when enemy aircraft are discovered approaching a military installation, city, coastline, etc.

2. the signal or alarm sounded for this alert.

3. any primary stage of alert, as when toxic chemicals have escaped in a particular area and a potential hazard exists.

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Etymology

Origin of yellow alert

First recorded in 1965–70

Example Sentences

The Met Office yellow alert lasts from 21:00 GMT on Saturday until 21:00 on Sunday.

From BBC

A yellow alert for snow and ice is in place for Counties Donegal, Cavan, Monaghan, Louth and Connacht.

From BBC

A yellow alert for County Donegal lasts from 20:00 local time on Friday until 11:00 on Saturday.

From BBC

An amber weather warning was in place in the Western Isles while the south of Scotland was covered by a yellow alert.

From BBC

A yellow alert for snow affects most of the mainland north of Perth from 03:00 until 18:00 on Tuesday, after the Highlands saw its first snowfall of the season last week.

From BBC