In the Weather & Society Discussion Board (AMS), as expected, there has been an exponential increase in content related to extreme weather in the US over the last two months. There was one thread in particular that raised a good topic:
….strongly recommend Economic and Societal Impacts of Tornadoes just released by Simmons & Sutter, and pulled a few points from Chapter 4 of the book.
Warnings with lead times up to 15 minutes reduce both fatalities and injuries, but we find no additional reduction of casualties for lead times beyond 15 minutes. We also find that tornado watches have no effect directly on casualties, although they do contribute as part of the warning process to saving lives.Together these findings suggest that residents do not appear to need lengthy advance notice to protect themselves from tornadoes, at least given the traditional recommended protective actions.
We also found evidence of a false alarm effect, as a higher recent, local false alarm ratio significantly increases fatalities and injuries. […] We have not precisely quantified the warning-false alarm casualty trade-off, but simply knowing that the trade-off exists is significant.
We are now at a point where we can examine the effectiveness of the warnings beyond simple measures like lead time. Future research can consider the role of time of day in the warning process. Nocturnal tornadoes are much more dangerous, even when controlling for warnings and false alarms, presumably because residents are less likely to receive warnings for these storms.
Pg 170-171…
