The National Weather Service released their assessment report for the Joplin,Missouri tornado last week. That tornado was responsible for the death of 159 people and injured over 1000. The report has a lot of analysis on how the public responded to the warnings issued during the storm.
Through numerous interviews, it was discovered that the vast majority of Joplin residents did not immediately take cover, or move to a safer location upon hearing a tornado warning was issued. A high percentage of residents got their fist inclination of threatening weather when the sirens were activated, but this was taken as another false alarm by many.
The study concluded that sirens have lost credibility to most people, although it did prompt them to seek additional information. The report offers some interesting insights as to how individuals perceive weather warnings and makes some very good recommendations to improve the weather warning system.
I highly recommend reading the assessment and we have a link to it at wday.com under the easy link tab.