yellow alert

American

noun

(in military or civilian defense) the first alert given when enemy aircraft are discovered approaching a military installation, city, coastline, etc.
the signal or alarm sounded for this alert.
any primary stage of alert, as when toxic chemicals have escaped in a particular area and a potential hazard exists.

Etymology

Origin of yellow alert

First recorded in 1965–70

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

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

From BBC • Jan. 5, 2026

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 • Sep. 30, 2025

The yellow alert for strong winds, which may lead to some disruption, covers all of Northern Ireland and comes into effect at 03:00 GMT on Sunday until 15:00.

From BBC • Feb. 22, 2025

In Northern Ireland, a yellow alert for snow and ice warning will be in place until 11:00 on Tuesday.

From BBC • Jan. 6, 2025

Until further notice, we must proceed under a yellow alert during daylight hours and a red alert at night.

From The Test Colony by Marks, Winston K.

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023