Did you hear the St. Louis County emergency siren system test Monday? The county is in the process of switching from the old system of sirens to the new, and Monday at 11 a.m. the new, but not the old sirens went off. They’re tested every first Monday of the month.

According to the St Louis County Office of Emergency Management, chances are the siren you heard was louder than what you've heard in the past.

With the new system, 185 sirens are replacing 210 old sirens, but county Emergency Communications Network Director David Barney said many of the old sirens were installed in the 1960s and 70s and are defective. Also, no sirens were placed in the far west and far south parts of the county.

"These new sirens are more effective," he said. "We’ve spread them out so now we’re covering a very high degree of the population."

Barney said they have electronic means of knowing if a siren worked, but if you know of a siren that is too faint or too loud call David Barney at (314) 615-2562. He also said the sirens are meant for outdoor warning only. The county recommends a weather radio for indoor warning.

Since the tornado hit Sunset Hills a year ago, and the Joplin tornado, some people are taking warnings more seriously.

Here are the emergency management office’s recommendations for what do when you hear a warning:

Basically, the advice is to seek shelter and seek information.

• If you are outside, go to a pre-designated shelter area such as a safe room, basement, storm cellar, or the lowest building level. If there is no basement, go to the center of an interior room on the lowest level (closet, interior hallway) away from corners, windows, doors, and outside walls. Put as many walls as possible between you and the outside. Do not open windows.
• Once you are inside and safe, turn on a TV, radio or National Oceanic and Atmospheric Administration weather alert radio to be informed of the storm location, path and the duration of the warning. There is no all-clear signal, once the warning has expired it is safe to leave your shelter location. Be aware, however, that the situation can change so be prepared in case another warning is issued for St. Louis County.
• We strongly recommend that every residence, business and school use a weather alert radio with battery back-up. Weather alert radios automatically activate to warn and inform you whenever a warning is issued for St. Louis County.

The University of Missouri Extension website provides more information about how to be ready for, and what to do during a storm.