Jefferson County this week will test a change to the outdoor siren system. Instead of sounding all sirens countywide during a tornado warning, the new system will activate only sirens located in or near the path of the storm. The county EMA said that the goal is getting more people to heed the warnings. The sirens are often ignored because the county covers more than 1,100 square miles, but a tornado's potential path is a small fraction of that area. The sirens will be tested Tuesday through Thursday, between the hours of 9 a.m. and 11 a.m. each day. The map above this article displays the dates and times of siren tests, by location.