Changes coming for Johnson County tornado sirens

Starting June 29, Johnson County officials will be able to sound outdoor warning sirens in certain parts of the county during severe weather.

The new system will allow dispatchers to limit sirens to those areas, or zones, under a tornado warning issued by the National Weather Service in the Quad Cities, according to a news release.

That's a change from the current system, in which the sirens go off countywide.

The new zones include one in the north covering Swisher, Shueyville and Solon; a central zone for Iowa City, Coralville, North Liberty, Oxford, Tiffin, University Heights and Hills; and one in the south that includes Lone Tree.

There also will be a countywide alert.

Sirens went off throughout Johnson County at 1 a.m. last Saturday after a police officer thought he saw a funnel cloud, although the National Weather Service did not issue any watches or warnings and radar did not detect any rotation during the storm.

The upgrades were made to tie in with the new countywide joint emergency communications center and accompanying radio system, the release said. The center goes live this week.

Also, the new siren system will use one tone for all emergencies, rather than the two sounds used in the old system depending on if the situation involved weather or national security.

The county also is changing when the outdoor warning system is tested. That will now occur at 10 a.m. on the first Wednesday of every month, instead of the 9 a.m. on the first Monday. The new time and day will coincide with National Oceanic and Atmospheric Administration indoor weather radio testing by the National Weather Service in the Quad Cities, according to the release.

Starting July 7, the system will go off twice during testing. Once in the zones and about five minutes later for the countywide siren.