Understanding Hurakans

Hurricane Isabel (2003)

Few natural phenomena can bring a civilization to its knees. Earthquakes, tsunamis, tornadoes, volcanic eruptions, and mud slides tend to come to mind. The Caribs, a West Indian tribal people, called them ‘Hurakan’ possibly adopted from the Mayans to describe a mythological “god of evil… who blew his breath across the chaotic water” leading to devastation.1 The Chinese referred to them as “tai feng” for great wind.2 I’m talking hurricanes. Known in meteorological parlance as tropical cyclones (or typhoons in the West Pacific), they arrive ceremoniously, so humanity can witness and experience the raw power of nature. The Southeastern United States is a perennial destination for hurricanes. They crop up constantly during their peak season, and it is even possible to experience several hurricane or near hurricane situations in a productive season. Some years we are lucky with minimal hurricane activity, and then some years we come face-to-face with some significant hurricane destruction. At present, a somber but massive hurricane, Hurricane Florence, made landfall in the Carolinas. Much of the area experienced widespread power loss and record flooding due to storm surge, leaving many residents displaced due to state-wide evacuations across several states, including the Carolinas, Virginia, and Georgia.

Hurricane Daniel (2006)

I decided to look back at older research and see what earlier researchers observed with these storms and how populations wrestled with such devastating acts of nature. In the modern age, we have had satellites and sensitive measuring equipment, but many decades ago such tools were unavailable. How did people handle or even describe these storms? What were their observations? In order to look into the past, we need to first understand as much basic knowledge about these tropical cyclones as we can. The National Hurricane Center (NHC), which falls under the auspices of the National Oceanic Atmospheric Agency (NOAA), hosts a wealth of information on tropical cyclones and safety resources. According to the NHC, a hurricane/typhoon is, “[a] tropical cyclone in which the maximum sustained surface wind (using the U.S. 1-minute average) is 64 knots (74 mph or 119 km/hr) or more. The term hurricane is used for Northern Hemisphere tropical cyclones east of the International Dateline to the Greenwich Meridian. The term typhoon is used for Pacific tropical cyclones north of the Equator west of the International Dateline.”3

Tropical cyclones form in their respective cyclonic basins in the tropics. It’s the area that surrounds the equator and provides the warmest sources of water. These cyclones begin as clusters of thunderstorms, which suck up the warm, moist air into the atmosphere and convert that warm air into energy which moves in a cyclonic pattern.4 This air moves around a low-pressure center region called the eye which can be around 20-30 miles, which is in turn surrounded by the eye wall.5 The eye itself doesn’t contain any strength aside from its posture as being organized or disorganized. Cyclones with disorganized eyes tend to have a more difficult time becoming stronger storms, with cyclones having more organized eyes giving it an edge in increasing strength and sustainability over the course of its journey across the cyclonic basin. With the eye wall, this region of the cyclone has the fastest wind speeds of the whole storm system.6 This area is where the wind can cause serious or catastrophic destruction. Surrounding this area is the rain bands, and this region can be tens or even hundreds of miles wide.7 The rain band region is even able to produce tornadoes. It’s this region that brings much of the storm surge and extensive rainfall on populations.

Given their power and notoriety, these storm systems primarily affect specific regions of the world. According to the Atlantic Oceanographic & Meteorological Laboratory, “there are seven tropical cyclone ‘basins’ where storms occur on a regular basis”: the Atlantic basin, the Northeast Pacific basin, Northwest Pacific basin, North Indian basin, Southwest Indian basin, Southeast Indian/Australian basin, and the Australian/Southwest Pacific basin. The NHC suggests, “approximately 69 percent of the tropical cyclones occur in the Northern Hemisphere, while only 31 percent can be found in the Southern Hemisphere…[with] approximately 12 percent occur[ing] in the Atlantic Ocean [and] 57 percent occur[ing] in the Pacific and the remaining 31 percent occur[ing] in the Indian Ocean.”8 Given the scope and scale, this shows the Earth pays witness to considerable amounts of devastation all over the world, every year.

These storm follow a streamlined classification system known as the Saffir-Simpson scale, which categorizes storm by their wind strength. This system was developed in order to help clearly explain to people the level of damage a pending tropical cyclone posed to the public once it made landfall. In 1971, Dr. Robert H. Simpson, director of the National Hurricane Center at the time, and Herbert Saffir, a consulting engineer with structural engineering background, devised this scale as a “better way to communicate what a storm is capable of doing”.9 Saffir’s expertise in wind damage was instrumental in helping Dade County with upgrading their building code, leading to a United Nations report to be used as guidance for whether “construction…could stand up to high winds.”10 Simpson, for his part, “had the responsibility for not only forecasting when, where, and how hard [hurricanes] would hit…but also convincing emergency management officials and the public [regarding the storm’s potential destruction].”11 The system was widely adopted in 1973, with the initial scale offering a separate scale for flood potential.

Saffir-Simpson Scale

The Saffir-Simpson scale has generated considerable debate about whether it needs to be updated to include other aspects of the storm, such as storm surge, flooding, or the rainfall levels. However, proponents argue the need for a simpler, clearer scale to help emphasize the level of danger to the public for evacuation purposes. Over the years, some hurricane seasons were more treacherous than others, such as the record-setting 2005 hurricane season where the Atlantic basin saw 31 tropical depressions, 28 tropical storms, 15 hurricanes, and 7 major hurricanes. This season was exceptional because it broke records across all categories. And in recent years, some storms such as Hurricanes Patricia (2015) and Irma (2017) were powerful and large storms, with Irma’s size being compared to roughly the size of Texas. Dr. Robert Simpson addressed years ago about such changes to the scale: “[W]hen you get up into winds in excess of 155 [mph] you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it’s going to cause rupturing damages that are serious no matter how well it’s engineered. It may only blow the windows out, but on the other hand, it can actually rupture the stairwells, the elevator wells and twist them, and it’s happened in many buildings so that you can’t even use the elevators after they’ve experienced this. So I think that it’s immaterial what will happen with winds stronger than 156 [mph].”12

Given this debate, long before satellites and more sophisticated equipment, weather researchers and scientists took to writing about and explaining these phenomena. An early scientific journal article by F. J. B. Cordeiro, “Tropical Hurriances,” discusses the overall organizing principles around how these storms are formed, as early as 1900. He posits openly, “[i]t will be interesting to attempt to trace the course of a hurricane from its birth to its end.”13 Yet, in his observations, he weaves together how trade winds factor into hurricane formation, in and around the doldrums, while wondering, “Why does the cyclone move and what are the laws governing this motion? Up to this time this part of the problem has been considered inexplicable. [Once we understand the] laws governing revolving storms[,] this knowledge could be applied with one bound from scientific guessing to an exact science.”14 It’s fascinating to see how much feeling in the dark researchers had to do in pursuit of understanding these storms. We are nowhere near an exact science on these storms when it comes to exactly predicting their path, yet we can watch them form and use that to extrapolate possible models. We, including the public now, depend on these models and trajectories to help us determine whether we are in the path storms and to plan accordingly.

Hurricane Elena (1985)

Forecasting has always been a difficult task before the modern age of meteorology. E. B. Calvert wrote, as part of T. W. Forman’s article, about the difficult job of weather forecasters as early as 1920. Calvert appeared concerned about an inability to predict or prepare for these storms: “If a hurricane should strike on the south Atlantic or Gulf coasts unheralded[,] the loss of life and destruction of property would be appalling. And this is what did happen before the Weather Bureau began its hurricane warning service and had learned the nature and characteristics of these awful maelstroms.”15 He compared the skills of a forecaster to that of a “physician who diagnoses a case in which there is menace and death to his patient by symptoms that he recognizes because of his technical skill and experience,” pointing out how forecasters have much less to go on by “[using] a single wireless report of weather conditions from a vessel at sea or a land station a hundred miles or more from the storm center.”16

What amazed me from reviewing this old literature is how much more we understand our climate and weather conditions. It was clear in his remarks that the true origins of hurricanes eluded professionals who studied the field as he suggested that hurricanes “may, and most frequently do, originate over the tropical waters of the Caribbean Sea and move for days without coming near land.”17 Even when we are regularly tracking hurricane formation off the West Africa coast. Even more problematic, he explained how “[f]or sixty hours, with only a few reports, none closer than 100 miles from the center of the disturbance, as a guide, the forecaster kept the people of the entire Gulf coast, who where in a fever of anxiety, in touch with the situation.”18 I cannot fathom the responsibility on the shoulders of forecasters at the time. We openly criticize them now, and I think given this early recounting that we should be thankful to have people dedicated to this service. Imagine the amount of lives saved since then?

Hurricane Lane (2018)

A more recent article that appeared in the Science journal in 1939 highlighted the disjointed operation to the then-named US Weather Bureau. The bureau depended on information across a large distance to help formulate forecasts and predict when to initiate hurricane warnings: “Observations are taken twice daily from over eighty stations in the West Indies and the Caribbean, and two to four times daily from vessels in the Gulf of Mexico, Caribbean and West Indian waters. These observations are in addition to the reports from the regular system of stations in the United States and vessels in the North Atlantic.”19 The brief synopsis described this organizational method as being “more efficient” and having more “effectiveness” in providing forecasters. Keep this in mind when we complain the efficacy and ever-changing nature of forecast modeling today.20 F. W. Reichelderfer, director of the US Weather bureau, posits that “‘[t]hese advices serve as examples of the remarkable accuracy with which the movement and intensity of violent storms can be foretold by means of the hurricane warning system.’”21 The operational capacity to predict and analyze tropical cyclone behavior required many different sources and the ability to digest the data and provide meaningful public notification or warning.

Stephen Visher, on the other hand, discussed these cyclones but took a unique approach in his article, “Storms of the World,” written in 1944. He discusses various storm systems including tropical cyclones, where he explains these tropical cyclones, “affect significantly more than one-fifth of the globe and the world’s population,” however, he suggests that areas around the globe benefit from these storm systems.22 He contends they provide much needed moisture to drier areas: “They do this chiefly by bringing rainfall to large parts of the tropics which otherwise would be too dry.”23 I find that line of reasoning interesting, but I found his later characterization of these storms as rather naive and boorish. It’s clear based on his observations that he sees these natural phenomena as being less destructive, commenting flippantly that “the terribly destructive type rarely occurs, except in the Far East.”24 His discourse on death tolls in the Far East were alarming; I could not imagine a person speaking so wantonly about human loss of life no matter their locale acceptable. If only Visher witnessed the sort of storms that nations and people around the world now experience maybe he would have more sympathy for the level of destruction. We had a storm like Hurricane Irma come from the Atlantic last year with the ability to affect a whole region. At one point, Irma was able to affect states as far north as Pennsylvania while pummeling Florida upon landfall there. Modern storms are more complex and bring a whole host of factors whether it be storm surge, flash flooding, or tornadoes.

Hurricane Irma (2016)

In reflection, it’s clear we have matured in our understanding of weather. What’s remarkable is the basic fundamentals surrounding weather have largely stayed in tact. This notion speaks to the skill and expertise of people serving in meteorology. Given that Hurricane Florence has been on my mind for the past week, I found this research to be powerful in given a broader context of how we’ve tweaked our understanding on something so powerful and dangerous. I salute the many scientific professionals who have spent their time year after year now, and in the past, studying every facet of these cyclones. In spite of our public frustrations over whether the hype is real for these storms. Forecasters and other weather professionals share a heavy burden in providing the best information they can to help large amounts of people make necessary decisions to save lives and, hopefully, property. As I write this, Hurricane Florence has passed my area. We were lucky, with minimal, if any, wind damage and marginal flooding in places. Just as she arrived with a clarion call, Florence peters away to nothing. It’s nature’s true irony that nothing wields such immense power for long. It’s almost like nature is constantly reminding us that the time comes for us all. No one thing that exists in nature holds such unbelievable amount of power for too long. So we look to the next pending disaster and the possible destruction it brings. These storms will continue to be our collective burden, as they will inevitably impact us. Sharing and growing this knowledge will help us in facing the continued challenges of these tropical cyclones. The more we understand them, the better prepared we can be. Challenges, I believe, we can continue to overcome.