weather communications

While a major winter storm last month was plastering the United States from Texas and New Mexico to New England with heavy snow and ice, volatile conditions in the Southeast (SE) spawned damaging and deadly tornadoes. One of these overnight Monday, February 16, tragically took the lives of 3 people and injured 10 in coastal North Carolina. Such nocturnal tornadoes are common in the Southeastern U.S.—a unique trait—and represent an extreme danger to sleeping residents.

From the first 🌪️🌪️ in #flwx & #gawx to the #tornado preliminarily rated EF3 in #ncwx — radar imagery and CAPE pic.twitter.com/Ow02xSwlaP

— Stu Ostro (@StuOstro) February 16, 2021

Compounding this problem, new research in the AMS journal Weather, Climate, and Society suggests there may be a deadly disconnect between tornado perception and reality in the region right when residents instead need an acute assessment of their tornado potential.
The article “Do We Know Our Own Tornado Season? A Psychological Investigation of Perceived Tornado Likelihood in the Southeast United States,” by Stephen Broomell of Carnegie Mellon University, with  colleagues from Stanford and NCAR, notes the tragic results of the regional misperception:

The recurring risks posed by tornadoes in the SE United States are exemplified by the significant loss of life associated with recent tornado outbreaks in the SE, including the 2008 Super Tuesday outbreak that killed over 50 people and the devastating 27 April 2011 outbreak that killed over 300 people in a single day.

Their survey of residents in seven states, from Louisiana and Arkansas to Georgia and Kentucky, representing the Southeastern region, finds that the residents perceive their tornado likelihood differently than meteorologists and experts familiar with Southeastern tornado risk. This puts them at great risk because residents’ experiences don’t match what actually happens where they live.

Broomell and his fellow researchers contend that Southeast residents may be misusing knowledge of Great Plains tornado events, ubiquitous in tornado chasing reality shows and social media videos, when determining their own risk. A fatal flaw since tornado behavior is different between the two regions.
For starters, unlike in infamous “Tornado Alley” states of Texas and Oklahoma north through Nebraska and Iowa into South Dakota, the Southeast lacks a single, “traditional” tornado season, with tornadoes “spread out across different seasons,” Broomell along with his coauthors report, including wintertime. The Southeast also endures more tornadoes overnight, as happened last week in North Carolina. And they spawn from multiple types of storm systems in the Southeast, more so than in the Great Plains. This makes knowledge about residents’ regional tornado likelihood especially critical in Southeastern states.

Another recent study published in the Bulletin of the American Meteorological Society, “In the Dark: Public Perceptions of and National Weather Service Forecaster Considerations for Nocturnal Tornadoes in Tennessee,” by Kelsey Ellis (University of Tennessee, Knoxville), et al., surveyed residents of Tennessee and came away with similar findings about tornado timing: about half of Tennessee’s tornadoes occur at night, and yet less than half of those surveyed thought they would be able to receive nighttime tornado warnings.

Local forecasters and broadcast meteorologists as well as emergency managers are tuned into the mismatch. In the BAMS study, NWS forecasters said they fear for the public’s safety, particularly with nighttime tornadoes, because they “know how dangerous nocturnal events are”—fatalities “are a given,” some said.

Ellis and her colleagues recommended developing a single, consistent communication they term “One Message” to focus on getting out word about the most deadly aspect of the tornado threat. Forecasters, broadcasters, and emergency managers through regular and social media would then be consistent in their messaging to residents, the researchers state, decreasing confusion. For example:

Nighttime tornadoes expected. Sleep with your phone ON tonight!

With severe weather season ready to pop as spring-like warmth quickly overwhelms winter’s icy grip in the next couple of weeks, the nation’s tornado risk will blossom across the South and Southeast. And nocturnal tornado threats will only increase, particularly in the Southeast, as February turns into March, and then April—a historically deadly month.
For residents in places more prone to nighttime tornadoes, Ellis et al. say the ways to stay safe are clear:

Have multiple ways to get tornado warnings, do not rely on outdoor sirens, sleep with your phone on and charged during severe weather, and do not stay in particularly vulnerable locations such as mobile homes or vehicles.

With Hurricane Delta poised to strike Louisiana today, the risk of embedded tornadoes will increase as rainbands spiral ashore, along with the primary threats of storm surge and damaging winds. Delta is forecast to plow well inland Friday night into the weekend, continuing a low risk for tornadoes, some of which could occur at night in Alabama, Mississippi and into southern Tennessee. The threat is more than a bit worrisome as new research in BAMS finds through phone surveys and followup interviews in Tennessee that people are woefully unprepared for nocturnal tornadoes.
In their article,” Kelsey Ellis and colleagues found a host of poor practices by residents when it comes to tornadoes at night. The authors recommend forecasters narrow their messaging about nocturnal tornadoes in the Southeast to a single important message to limit confusion.
Almost half of Tennessee’s tornadoes occur at night, as in other Southeast states with large numbers of nocturnal tornadoes, and are two-and-a-half times as deadly as daytime tornadoes. This creates detection, warning, and public response challenges. Yet, respondents in the western part of the state overestimated tornado occurrence at night while those in the east substantially underestimated the number.
Additionally, nearly half of participants in the survey say they rely on sirens to receive tornado warnings. This is despite the fact that sirens are not designed to warn people inside nor be loud enough to wake anyone up. Instead, Wireless Emergency Alerts (WEAs) “should be a constant,” the authors say. Also, people mentioned they rely on TV and social media for receiving warnings even though generally neither will wake you up.
The authors felt it was “dangerous” that even the more tech savvy and tornado aware respondents answered they were compelled to look outside for evidence of a tornado—even in the dark. Interviewees explained they were “checking for sounds instead of visual cues.”
NWS forecasters were also surveyed about nocturnal tornadoes. The forecasters mentioned the lack of ground truth and fear for public safety among challenges to the nighttime warning service. They noted few spotter or social media reports inform them if “the storm is actually showing the signs on the grounds that radar is indicating aloft.” Forecasters said they felt “fearful, worried, or nervous for the public during nocturnal tornadoes because fatalities ‘are a given.’”
The survey responses moved Ellis et al. to recommend a single-emphasis message be presented to residents to combat the nighttime tornado problem:

One strategy that may improve public safety during a nocturnal tornado event, and which addresses the forecaster challenge of communication prior to and during an event, is to develop “One Message”—a consistent message that EMs and the media use throughout broadcasts, briefings, and social media. Examples of messages could be: “Nighttime tornadoes expected. Sleep with your phone ON tonight!” or “Tornadoes will form quickly! Make plans now where you will take shelter!” or “If you live in a manufactured home, you may not have much time to seek shelter tonight!” One Message may decrease confusion for receivers, making them more likely to make safe decisions. Messages could similarly be used to dispel misconceptions about local geography in ways relevant to the specific listening area, for example: “You are not protected by nearby hills. Seek shelter immediately!”

With Hurricane Delta’s nighttime tornado threat ramping up, the authors suggest people use multiple ways to receive warnings, keeps phones on and charged, don’t rely on tornado sirens, and if possible relocate ahead of the weather from “particularly vulnerable” situations, such as mobile homes and vehicles.

With Hurricane Delta poised to strike Louisiana today, the risk of embedded tornadoes will increase as rainbands spiral ashore, along with the primary threats of storm surge and damaging winds. Delta is forecast to plow well inland Friday night into the weekend, continuing a low risk for tornadoes, some of which could occur at night in Alabama, Mississippi and into southern Tennessee. The threat is more than a bit worrisome as new research in BAMS finds through phone surveys and followup interviews in Tennessee that people are woefully unprepared for nocturnal tornadoes.

In their article,” Kelsey Ellis and colleagues found a host of poor practices by residents when it comes to tornadoes at night. The authors recommend forecasters narrow their messaging about nocturnal tornadoes in the Southeast to a single important message to limit confusion.

Almost half of Tennessee’s tornadoes occur at night, as in other Southeast states with large numbers of nocturnal tornadoes, and are two-and-a-half times as deadly as daytime tornadoes. This creates detection, warning, and public response challenges. Yet, respondents in the western part of the state overestimated tornado occurrence at night while those in the east substantially underestimated the number.

Additionally, nearly half of participants in the survey say they rely on sirens to receive tornado warnings. This is despite the fact that sirens are not designed to warn people inside nor be loud enough to wake anyone up. Instead, Wireless Emergency Alerts (WEAs) “should be a constant,” the authors say. Also, people mentioned they rely on TV and social media for receiving warnings even though generally neither will wake you up.

The authors felt it was “dangerous” that even the more tech savvy and tornado aware respondents answered they were compelled to look outside for evidence of a tornado—even in the dark. Interviewees explained they were “checking for sounds instead of visual cues.”

NWS forecasters were also surveyed about nocturnal tornadoes. The forecasters mentioned the lack of ground truth and fear for public safety among challenges to the nighttime warning service. They noted few spotter or social media reports inform them if “the storm is actually showing the signs on the grounds that radar is indicating aloft.” Forecasters said they felt “fearful, worried, or nervous for the public during nocturnal tornadoes because fatalities ‘are a given.’”

The survey responses moved Ellis et al. to recommend a single-emphasis message be presented to residents to combat the nighttime tornado problem:

One strategy that may improve public safety during a nocturnal tornado event, and which addresses the forecaster challenge of communication prior to and during an event, is to develop “One Message”—a consistent message that EMs and the media use throughout broadcasts, briefings, and social media. Examples of messages could be: “Nighttime tornadoes expected. Sleep with your phone ON tonight!” or “Tornadoes will form quickly! Make plans now where you will take shelter!” or “If you live in a manufactured home, you may not have much time to seek shelter tonight!” One Message may decrease confusion for receivers, making them more likely to make safe decisions. Messages could similarly be used to dispel misconceptions about local geography in ways relevant to the specific listening area, for example: “You are not protected by nearby hills. Seek shelter immediately!”

With Hurricane Delta’s nighttime tornado threat ramping up, the authors suggest people use multiple ways to receive warnings, keeps phones on and charged, don’t rely on tornado sirens, and if possible relocate ahead of the weather from “particularly vulnerable” situations, such as mobile homes and vehicles.