At 5:35 P.M. on September 17, 2018, the University of Maryland Police Department (UMPD) sent a tornado warning by email and text message to university students, faculty, and staff: "A Tornado Warning has been issued for the UMD campus. The sirens will be activated. Seek shelter immediately, avoid windows." This message did not mention that the warning was issued by Accuweather. The National Weather Service (NWS) did not issue a tornado warning. At 6:04 P.M., the UMPD sent the following message: "The Tornado Warning that was issued by AccuWeather is now cancelled as of 6:00 PM."
Part of Accuweather's business is generating severe weather alerts for its clients. Its website touts the benefits of Accuweather's warnings and its "null tornado notifications" that a NWS tornado warning will not affect a client's facility. The website discusses the benefits of knowing that a tornado warning is not a direct threat, so a shutdown is not necessary, and claims that Accuweather's false alarm rate is lower than the NWS false alarm rate (10% to 80%).
When one organization issues a warning while the other does not, the inconsistency could decrease trust in warnings, increasing the likelihood of ignoring warnings.
An article in The Washington Post about the false alarm (Angela Fritz and Sarah Larimer, "Red flags at U-Md. over false alarm for tornado," September 19, 2018) quoted Gary Szatkowki, a former NWS meteorologist, who asked "What do we want to do about a weather organization issuing a tornado warning when the Weather Service does not?"
Although the University of Maryland is a large institution (approximately 40,000 students), its cost of a false alarm is smaller than the same cost for a factory (where a shutdown directly impacts throughput and revenue). Moreover, many students and others are outdoors, and the university has a strong desire to be viewed as a safe place, so the potential impact is large.
In that case, the university should be willing to tolerate more warnings. Too many warnings? No, in this case.
