Grand Rapids will upgrade the city's emergency siren system, spending $140,000 on half a dozen new sirens.

The city also plans to move a couple others to improve their audible coverage. 

WOOD TV reports the tornado sirens are not supposed to be so loud as to wake you up at night, but are there to warn people who may be outside, walking their dogs or biking, or something.

The sirens are sounded in conjunction with official warnings also posted on various social media, including WOOD Radio, and the National Weather Service alerting receivers.