yellow alert

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.

Word History and Origins

Origin of yellow alert¹

First recorded in 1965–70

Example Sentences

The Spanish island also issued a yellow alert for thunderstorms, from 08:00 until 18:00 on Tuesday.

From BBC

Mallorca, another Balearic island, is also at risk of heavy rainfall and floods with Spain's weather agency, known as Aemet, placing it under a yellow alert for rain and thunderstorms.

From BBC

North East England, North West England, Yorkshire and Humber and south-west England have a yellow alert for the same period.

From BBC

Meanwhile, Yorkshire and Humber and the West Midlands are under a less serious yellow alert.

From BBC

It has issued a yellow alert which means that the heat is tolerable for the general public but can cause moderate health concerns for infants, the elderly and people with chronic diseases.

From BBC