|National Center for Atmospheric Research (NCAR). Click to enlarge.|
For about five years, a group of research meteorologists in Norman, OK along with a few others in Boulder, CO and Washington, DC have been pressing to change the tornado warning system into one that is based on probabilities as depicted above.
Now, tornado warnings are a yes/no system where "yes" means take protective action.
Is a completely changed tornado warning system a good idea? I think not.
Let's deconstruct NCAR's example above:
Imagine your cellphone going off at midnight...
I don't want my cellphone going off unless someone is giving me emergency information. Too many non-emergency messages leads to the cellphone being completely turned off rather than left in sleep mode.
We have already seen this played out with NOAA Weather Radio. Lots and lots of people have purchased the radios only to junk them because they are constantly going off in the middle of the night with non-desired messages.
... at midnight... Between 1:00 and 1:30 a.m. there is a 50% chance...
Yes, and there is a non-zero chance the thunderstorm will dissipate all together and there is an even better chance the threat will change direction. By doing this an hour in advance we greatly increase the chance of ending up with egg on our face.
... a 50% chance that a tornado will pass within two miles of your house.
OK, you are awakened from a sound sleep. What, exactly, are you supposed to do with that message??!! What does 50% mean in this context? I contend, when given something they aren't sure what to do with, most would just go back to sleep, "Wake me up in an hour when it time to do something."
Later in this same document, the head of NOAA (the parent agency of the National Weather Service), Jane Lubchenco, is quoted as saying, "Do people hear and understand the information we think we are providing?" That is an excellent question. There is certainly a role for the social sciences to make our existing system clearer and more actionable.
The existing watch/warning system has been in place for a half-century and there are still people who do not understand it. Trying to educate people on a probability-based system (when do you go to the basement, 5%, 15%, 50%, 78%?) will take a century or more.
There may well be a place for "probability of tornado" for governmental emergency managers and other specialized users. For the public? It will do far more harm than good.