If you hear a tornado siren for a few seconds on some random weekday afternoon this fall, check the sky, but don't panic yet. The city says Hennepin County is continuing to upgrade the outdoor warning sirens that serve Bloomington, and short test blasts are part of the job.
The work replaces the control system that sets off about 300 outdoor warning sirens across the county. The sirens themselves are owned by the cities, but the county runs them as one coordinated network. The city says it's the largest coordinated outdoor alarm system in the state, and the county calls it one of the largest in the country.
The county says the goal is "faster, more precise and reliable warnings." In practice, that should mean fewer sirens going off in neighborhoods that aren't actually at risk. If you've ever stood under a wailing siren while the storm missed your side of the 494 corridor completely, that's the problem they're trying to fix. Technicians will also get better real-time data on whether each siren is working.
The switchover will take several months, and the old and new systems will run side by side until it's done. Meanwhile, technicians may set off individual sirens for "short growl tests that last 10 to 15 seconds" to confirm each one works. A short, low growl is a test. A full, sustained wail outside the scheduled test time is the real thing, so go inside and check local alerts.
The regular monthly test isn't changing. It still happens at 1 p.m. on the first Wednesday of each month, so the next one falls on Wednesday, Nov. 4. The county says the monthly test may sound a little different or come at a slightly different moment while the new system is being tested, and that's normal.
The county hasn't said what the upgrade costs, who the contractor is, or when the work will be finished. Residents with questions can call the Hennepin County info line at 612-348-3000. The county's full announcement is part of its extreme-weather preparedness page, which also points to the county's emergency management office.
One thing to remember: outdoor sirens are designed to warn people who are outside. They aren't meant to wake you up in a basement bedroom. That's still the job of a weather radio or the emergency alerts on your phone.
