I recently spent a lot of time trying to help a man understand that not every tornado will be preceded by a warning; there was none for the twister that destroyed a Family Dollar store on South Broad Street May 6. Fortunately, no one was hurt by the one-minute-long, 25-yard-wide tornado. The man was upset and wouldn’t accept that technology and meteorologists could possibly miss a tornado. It did and we do, and I’m not happy about it. I am acutely and painfully aware that misses happen.
The man questioned how a warning could be issued for the tornado that later happened in Daphne, but not for the one that caused damage in Mobile. The Mobile tornado was the first of the night. It was brief and tiny, following a rapid spin-up with a subtle and minimal signature.
Since the setup of the atmosphere is different every time there’s a tornado threat, we don’t always know the threshold of when the first tornado can form. It was not obvious in this Mobile case. The thunderstorm that created the tornado in Daphne did have an obvious signature for a few minutes, crossing Mobile Bay, before it touched down.
There are certain conditions that make you sneeze, right? Predict exactly when you will next sneeze. You can’t, but once you start sneezing, it’s easier to predict if/when you will sneeze again. It is impossible by using technology or human ability to predict every tornado, especially the first one, the same way doctors cannot predict every disease you will have.
A desire to be warned for every single tornado requires many more tornado warnings to be issued, for anything that has the smallest potential of becoming a twister. You probably don’t want that, just like you probably don’t want your doctor to call you about everything that has a tiny and questionable likelihood of becoming a concern. When false alarms increase, we lose trust. It’s a delicate balance.
As we enter hurricane season, that same warning challenge shifts to tropical weather, coming with the stress of being bombarded by graphics and headlines of long-range outlooks and forecasts on social media. Carefully read the posts and count how many times you see the words “could,” “might” and “may,” and remember that those are far different from “likely” or “will.”
While social media platform algorithms raise the visibility of popular posts, no amount of social media opinion and speculation controls weather. Keep a realistic perspective of the limits of science and computer models. Thank you for reading beyond the picture and beyond the headline.
Too often, people share a post with me and ask, “Is this true?” In forecasting, only the past and the present have “truth”; the future has probability. It is true that a 14-day weather model forecast looks just like a tomorrow weather model forecast, but it’s not as accurate. Bookmark the graphic and look at it two weeks later to see if it’s near reality.
Alan Sealls is chief meteorologist at NBC15 and an adjunct meteorology professor at the University of South Alabama.
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