The Boulder County Sheriff's Office is updating its emergency alert system by adding Hi/Lo evacuation sirens to patrol vehicles [1].
These changes aim to improve the county's ability to spread emergency alerts quickly and ensure that siren systems function properly during floods or other crises [1, 2].
As part of the new protocol, outdoor emergency sirens will be tested once a month [2]. According to KDVR, "Outdoor emergency sirens will soon go off once a month, year‑round, for testing around Boulder County" [2].
These monthly tests are scheduled for the first Monday of each month at 10 a.m. [2]. The schedule is designed to maintain system readiness throughout the year, regardless of the season.
In addition to the outdoor sirens, the Sheriff's Office is introducing the Hi/Lo siren specifically for patrol vehicles [1]. This specialized siren is intended to signal evacuations, providing a distinct audio cue to residents that they must leave the area immediately.
Local officials said the combined approach of vehicle-based sirens and fixed outdoor alerts creates a more robust warning network [1, 2]. This ensures that residents are notified whether they are near a fixed siren tower or in the immediate vicinity of a responding deputy.
“Outdoor emergency sirens will soon go off once a month, year‑round, for testing around Boulder County.”
The shift toward monthly testing and the adoption of Hi/Lo sirens reflects a move toward more aggressive and redundant warning systems. By diversifying the types of alerts—combining stationary sirens for broad area warnings with mobile sirens for targeted evacuations—Boulder County is attempting to eliminate gaps in communication during rapid-onset disasters like flash floods.
