Eulerian Weather, Lagrangian Lives

by Alan E. Stewart, University of Georgia

It is clear that Covid-19 will be with us for a while. So will the weather, however. We’ve been through flooding in Michigan in mid-May; an outbreak of 140 tornadoes from Texas to Maryland in April; a deadly and destructive derecho in Iowa; hurricane landfalls in Louisiana, Alabama, and Florida; and massive wildfires in the West. In other words, the weather, as always, just is—it exists and occurs as a series of events that intertwine with the activities and challenges of our daily lives. Here, I would like to borrow from dynamic meteorology and apply the concepts of the Eulerian and Lagrangian perspectives to discuss our experiential journeys through the weather and Covid-19. I also will query what this means for how we cope when severe weather threatens us during this pandemic.

From the Eulerian perspective, we depict the current weather or make a forecast for a given space (county warning area, city, state, region) for a time (6 hours, 12 hours, and so on). We concern ourselves with what will occur inside the grid boxes of a model—what is the flux of weather into and out of the area? Similarly, when we look out of the windows of our life-spaces we see and experience the weather. And what is so striking about what we see is that most of the time the weather seems within its usual seasonal limits—climatologically speaking. The weather is often pleasant. It seems not to have gotten the message about Covid-19.

How could it? The weather just is. Some people have told me that during the pandemic, the closures, and the quarantines, the weather is about the only thing that has remained normal in their lives—and this has provided some degree of comfort. But with a wildfire or a hurricane, this can change quickly. Some of the same states that are threatened by hurricane landfall already have been ravaged by Covid-19.

We can think of peoples’ paths through the meteorological and nonmeteorological events in their lives with the Lagrangian perspective—metaphorically speaking. Life is a journey, a narrative, a path or a force that moves forward in time; sometimes the trajectory changes unexpectedly. The Lagrangian perspective involves the accumulated experiences of the weather through the eyes of the perceivers— individual people. Such Lagrangian living with or “under” the weather builds a corpus of weather experiences that subtly or sometimes significantly changes peoples’ subsequent responses to the weather . All of us are, to varying extents, products of what we have experienced, including the Covid-19 pandemic. So many people—in Michigan, Iowa, California, Louisiana, and elsewhere—have experienced life with both Covid-19 and disaster and displacement.

In dynamic meteorology we learn to use both the Eulerian and Lagrangian perspectives; we segue between the two to build a fuller understanding of the atmosphere. What might we learn and what questions arise when we juxtapose my uses of these perspectives? These are timely questions to consider as we deal with hurricanes, winter storms, and other weather threats during the Covid-19 pandemic.

Trust of Message Sources: During the Covid-19 pandemic, different state and federal agencies often have issued confusing, sometimes contradictory reports and recommendations about the virus. How have peoples’ experiences of this messaging affected the ways that they may receive and act upon forecasts, watches, and warnings for severe/extreme weather? How might weather-related messages from local emergency managers or health departments be received? To what extent has the trust in the weather enterprise been affected by pandemic-related messaging?

Risk Perception and Tolerance: People have dealt with multiple risks thus far during the pandemic: health, economic/financial, social, and psychological, among others. Have the experiences of these risks affected how people perceive additional risks from thunderstorms, tornadoes, floods, and hurricanes? Because people may have successfully survived an infection with Covid-19, does this affect how they perceive their risks to natural hazards? Do some people feel lucky? Because people may be more desperate for work or to keep a job, might they take additional risks to do their jobs during bad weather? Might some businesses take extra risks in bad weather to build a competitive advantage—to make up for past losses?

Preparation: As word of the pandemic spread, people in many places stocked up on consumables for daily living, leading to shortages of some items. Given how the pandemic has unfolded in different parts of the country, are people still prepared? Have they exhausted those supplies and are people fatigued from stocking up? Are suppliers ready for further waves of Covid-19 and/or a major hurricane landfall? Has stocking up and preparing made people more ready for severe weather? Is there a new appreciation for being prepared for the unexpected?

Sheltering in Place: Some severe weather events involve sheltering in place. Given the extensive sheltering in many places in the spring because of Covid-19, would some prefer to shelter in place rather than risk Covid-19 exposure elsewhere? Alternatively, would some be less likely to shelter in place because they are fatigued from it?

Evacuation Planning: Important questions involve what happens when evacuations are necessary: For example, how can the spread of Covid-19 infection be limited? Are separate shelters needed for those who are infected? How does social distancing work in the close quarters of a shelter? Are more shelters needed? Do the existing shelters have a supply of face masks and other personal protective equipment?

Interdisciplinary social and atmospheric science points to an ever-motivating realization: Often it is not simply a matter of providing a timely and accurate forecast, but it is what people do with the information they have that affects the outcomes. This is unsettling because it is often out of the direct control of the weather enterprise—much as epidemiologists and physicians cannot control how people deal with the risks of Covid-19. Efforts to communicate effectively, educate, and persuade stakeholders about the weather take on great importance. Forecasts and warnings are absorbed by people who have experienced the varying and cumulative effects of Covid-19. Being mindful of this reality may help us to better prepare people and communities.




A Question for the Experts

There have been many thoughtful questions raised throughout this weekend’s AMS Student Conference, but one question posed at the communications breakout session on Saturday proved particularly challenging for the panelists. A student asked, “How do you educate the public that doesn’t have access to television or social media? How do we educate the homeless about severe weather events?”
Here were the responses from the panelists:
Marshall Shepherd, Univ. of Georgia: I think you’re hitting on a key question. The homeless question…that’s tough. These are the people who aren’t watching, necessarily. That really involves grassroots efforts. TV stations can be involved in galvanizing and organizing. So, for example, I teach a class at the University of Georgia on urban climate, and one of the projects I ask students to do is look at tornado sirens in the Athens/Clark County region. One of the things we found was that the way the tornado sirens were distributed, there were significant parts of the population—particularly those who were underserved or lower income—who didn’t even have sirens where they lived.
So I think there’s a whole notion of increased social sciences and environmental justice and all types of issues that we all have to be aware of and address.  I don’t know the answer to that question you asked, and I think there’s an opportunity.
Ginger Zee, ABC News: I’ve done four stories on that same thing of the sirens, because there’s no federal law, state law, no county law in any state that says there has to be one. I grew up in Michigan and we had them in every single town. It’s amazing to me that there are places that don’t have them, especially in places that really need them but don’t. Requiring outdoor warning systems—I don’t know if that’s going to happen; it’s not going to be funded.
I think the community outreach part is probably your best bet. You guys remember in Virginia this year, there was a camp with a bunch of kids outdoors and a long line of storms on the ground for three hours. It’s amazing to me that they still didn’t have warning. That can’t go on.  There was one kid who died. That shouldn’t have happened, because once they got indoors they were safe inside. If that was a fire and they didn’t have a smoke alarms, we would not be having the same discussion. They would have been sued like crazy.
Weather has grown…our ability to forecast has grown and now the whole policy part of it has to catch up. I think that will take time.
Keli Pirtle, NOAA: The National Weather Service works with local emergency managers to help prepare communities through the Storm Ready program.  I would hope that a shelter, like a homeless shelter, would have a NOAA Weather Radio. That’s a hope more than a reality, I’m afraid.  We can encourage people—churches, nursing homes, schools—to have multiple ways to receive information, to have a plan. A homeless person on the street, they’re in touch with others. I would hope the network on the street would get them the information, but it’s certainly an area where we desperately need to improve.
Jorge Torres, KOB-TV: And I agree with that. At our station, we’re partners with the Red Cross, and with the Roadrunner Food Bank of New Mexico, which helps feed the hungry because New Mexico is, I believe, the number one state in the country for childhood hunger. So we do have outreach programs with the lower-income communities. But that’s not in the form of weather [information] mostly, it’s in the form of talking to them. I do think you bring up a good point that those who don’t watch us, can’t watch us. They’re the ones who deal with the elements much more—the homeless especially—than the rest of us because we have a roof over our head and they don’t.

NWS Experiment Chooses Words To Improve Warnings

The National Weather Service recently announced plans to expand the use of its experimental impact-based storm warnings to include all 38 branches of the NWS Central Region. The warnings go beyond a simple explanation of a storm’s strength by communicating specific effects that the storm could cause, using descriptions like “major house and building damage likely and complete destruction possible,” “major power outages in path of tornado highly likely,” and “complete destruction of vehicles likely.” The warnings were implemented last year in Kansas and Missouri, and officials believe they helped prevent fatalities during a tornado outbreak in Kansas last April 14. The effectiveness of the warnings last year will be examined in more depth in a presentation at the Second AMS Conference on Weather Warnings and Communication, which will be held this June in Nashville (in concert with the 41st Conference on Broadcast Meteorology) .
These new warnings are just one example of the advances made in communicating dangerous weather events to the public, and the Nashville conference will examine a number of methods, including the use of social media and mobile apps. The meeting will also look at how the general public responds to various types of warnings, and explore both old and new technologies in warning systems. The full program for the conference can be found here.
Clarity of communication is a key to the impact-based warnings. According to this story in the Wichita Eagle, emergency officials are praising the vernacular of the new warnings. Michael Hudson, chief operations officer for the NWS Central Region headquarters in Kansas City, Missouri, noted that “emergency managers liked the extra information that was in the warnings–the information that got to the magnitude of the weather.” In specific reference to the intense tornado in Sedgwick County, Kansas, last April, that county’s emergency management director, Randy Duncan, felt the language in the impact-based warnings “helped to convey how serious the situation was, and the fact that we didn’t have any fatalities means–at least in my mind–that people in Wichita paid attention.”
The expanded use of the warnings this year will include some minor revisions resulting from some lessons learned in last year’s experiment. One change is the new use of the word “considerable” instead of “significant,” because “significant” was considered by many users to be too vague. Hudson explained that forecasters are instructed to consider “what you’d tell your wife or husband or children” about the potential threat of a storm.

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New Warnings, New Words

National Weather Service offices in Missouri and Kansas recently initiated an experiment testing new tornado warnings that combine more specific information with more descriptive language than have been used in the past to describe the potential effects of storms. The experiment is called “Impact Based Warning,” and is meant to bluntly tell residents in the path of tornadoes what could result if they don’t seek shelter. By using phrases such as “complete destruction” and “unsurvivable if shelter not sought below ground,” the NWS is hoping to “better convey the threat and elevate the warning over a more typical warning,” according to Dan Hawblitzel of the Pleasant Hill, Missouri NWS office.
The new alerts got their first big test last weekend when more than 100 twisters were reported in Kansas, Oklahoma, Nebraska, and Iowa. While the NWS’s Storm Prediction Center issued a warning of possible life-threatening storms in several midwestern states days before they touched down, in Kansas the words used in the new alerts were particularly trenchant: “You could be killed if not underground or in a tornado shelter. Many well-built homes and businesses will be completely swept from their foundations.” And the warnings seem to have worked. Despite the large number of storms, only six people were killed—all in an overnight tornado that hit Woodward, Oklahoma. In Wichita, Kansas, a twister tore through a mobile-home park during nighttime hours, but there were no fatalities.
The Impact Based Warning experiment was developed by the NWS in consultation with social scientists. Along with the new vernacular, it includes some key additions to regular tornado warnings, including information that identifies the hazard (hail, winds, tornado, etc.), indicates whether the hazard has been spotted by radar or by people on the ground, and describes potential effects of the hazard (loss of life, damage to trees or buildings, etc.). The warnings can be used not only for tornadoes, but also to signify life- or property-threatening thunderstorms. The experiment is scheduled to run through the end of November, at which point it will be evaluated and considered for more widespread use.
The initiative comes  just one year after tornadoes killed more than 500 people in the United States—the deadliest season in almost 60 years. The 2011 year in tornadoes is examined in the new AMS book, Deadly Season: Analysis of the 2011 Tornado Outbreaks, by Kevin M. Simmons and Daniel Sutter. The book is a follow-up to the authors’ Economic and Societal Impacts of Tornadoes, published by AMS in 2011. The new title looks at possible factors contributing to the outcomes of 2011 tornado outbreaks, including assessments of Doppler radar, storm warning systems. and early recovery efforts. Both books can be purchased here.