Emergency communication system
161 people were killed and at least 990 injured when an EF5 multiple-vortex tornado hit Joplin, Missouri. Because Joplin is located in a tornado-heavy area of the country, many people considered the tornado sirens routine and ignored them. Instead, many residents waited until they received confirmation from another, non-routine, source, such as seeing the tornado, a radio or TV report, or hearing a second siren. In the aftermath, an assessment team recommended that emergency warnings take risk perception into account to convey a sense of urgency. NOAA Officials are considering ways to change the warning system to distinguish smaller tornadoes from more deadly ones.
January 2008 tornado outbreak
A strong low-pressure area over the central Great Lakes and its associated cold front combined with intense wind shear to provide a favorable environment for supercell development. Despite only moderate instability (which meant only a slight risk of severe weather was issued by the Storm Prediction Center, and only modest probabilities for severe weather at first), supercells developed throughout the day over much of the central US and continued throughout the evening and overnight hours, continuing into the morning of January 8. The hardest-hit area was in the Ozarks, around Springfield, Missouri, where nearly continuous supercells developed throughout the evening, resulting in numerous tornado touchdowns. In addition to the tornadoes, hail larger than baseballs and damaging straight-line downburst winds as strong as 100 mph (160 km/h) were reported. At least three people were killed in Missouri as a result of the tornadoes. Two of these deaths occurred near Marshfield and there were also six injuries.