The unprecedented and extraordinary occurrence of Tropical Storm Hilary’s devastating impact on California and Nevada can be attributed to a confluence of various factors, including a natural El Nino phenomenon, human-induced climate change, and the persistence of a heat dome over the nation’s midsection.
Scientists have meticulously analyzed the intricate interplay of these elements, ultimately concluding that the storm’s formation and subsequent trajectory were heavily influenced by the presence of hot water and hot air.
This unique combination facilitated the rapid intensification of Hilary and guided its extraordinary path, resulting in an astonishing deluge of rainfall that surpassed the annual average in a mere weekend in typically arid regions.
Astonishingly, some areas in Southern California’s mountains received nearly a foot of rain, while cities shattered long-standing summertime precipitation records.
The convergence of these circumstances, as elucidated by esteemed atmospheric scientist Kristen Corbosiero from the University of Albany, created an ideal scenario that rendered the storm’s occurrence possible.
Determining the direct correlation between a specific event and climate change is a challenging task, particularly when considering the rapidity with which such attributions are made, and the significant influence of El Nino.
These assertions were made by Jim Kossin, a former scientist specializing in hurricanes and climate at the National Oceanic and Atmospheric Administration, who currently works at the nonprofit organization, First Street Foundation.
Kossin’s statement highlights the complexity involved in establishing a causal relationship between climate change and a singular occurrence.
With multiple factors contributing to the Earth’s climate patterns, it becomes increasingly arduous to pinpoint the precise impact of global warming on a specific event.
Additionally, the presence of El Nino, a climatic phenomenon characterized by warm oceanic currents in the Pacific, further complicates the analysis.
The interplay between El Nino and climate change necessitates a comprehensive examination of various factors before any definitive conclusions can be drawn.
In order to gain a comprehensive understanding of Hilary’s atypical trajectory, it is imperative to delve into the origins of the storm.
Hilary took shape in a region located south of Baja California and west of Mexico, an area notorious for the formation of numerous storms in the Eastern Pacific.
However, the majority of these storms typically meander harmlessly westward into the vast expanse of the Pacific Ocean or traverse Mexico, eventually losing strength as they make their way into the southwestern United States.
This particular region is renowned for being an incredibly active breeding ground for tropical cyclones, as noted by Corbosiero, an expert in the field.
Nevertheless, what set Hilary apart was the astonishingly high temperature of the water, the primary source of energy for the hurricane.
UCLA’s esteemed western weather scientist, Daniel Swain, revealed that the surface temperature of the water was approximately 3.5 to 5 degrees Fahrenheit (2 to 3 degrees Celsius) above the norm, and this abnormal warmth extended deep into the ocean.
Consequently, Hilary experienced a rapid intensification, with its wind speed increasing by a staggering 75 mph within a mere 24-hour span, propelling it from a relatively innocuous entity to a formidable Category 4 hurricane in an astonishingly short period of time.
According to Kossin, a researcher who conducted a study on the subject, there has been a noticeable increase in the occurrence of rapid intensification in storms.
He explains that for a storm to intensify in the manner that Hurricane Hilary did, certain conditions must be met. These conditions include warm water, which not only runs deep but also experiences minimal crosswinds that could weaken the storm.
In the case of Hilary, all of these factors were present. The warm water can be attributed to both the natural phenomenon known as El Nino, which causes certain parts of the equatorial Pacific to warm, and the long-term climate change that has led to record-breaking heat in the deeper layers of the oceans.
Swain, a scientist from UCLA, points out that there are three main reasons why storms forming in the same region as Hilary typically do not affect Southern California as severely.
Firstly, unlike the hurricane-prone Atlantic coast, the California and Baja California coastlines have cold water that is brought up from the deep, acting as a deterrent for hurricanes. In other words, this cold water acts as a “hurricane killer.”
According to researcher Kossin’s study on the subject, there has been a noticeable increase in the occurrence of rapid intensification in storms.
Kossin explains that for a storm to intensify in the same manner as Hurricane Hilary, specific conditions must be met.
These conditions include warm water, which not only runs deep but also experiences minimal crosswinds that could weaken the storm. In the case of Hilary, all of these factors were present.
The warm water can be attributed to both the natural phenomenon known as El Nino, which causes certain parts of the equatorial Pacific to warm, and the long-term climate change that has led to record-breaking heat in the deeper layers of the oceans.
Another scientist, Swain from UCLA, points out three main reasons why storms forming in the same region as Hilary typically do not affect Southern California as severely.
Firstly, unlike the hurricane-prone Atlantic coast, the California and Baja California coastlines have cold water that is brought up from the deep, acting as a deterrent for hurricanes. In other words, this cold water acts as a “hurricane killer.”
The unexpected arrival of Hilary in California can be attributed to the failure of the usual prevailing winds that typically push storms from east to west, according to Swain.
Unusual atmospheric conditions, such as hot air to the east and a low-pressure system to the west, combined to divert Hilary from its normal path and steer it towards California.
Additionally, a large hot air mass situated over the middle United States prevented the storm from turning eastward.
The persistence of this stagnant hot air mass is highly unusual, and some scientists, like Jennifer Francis from the Woodwell Climate Research Institute, have suggested that this phenomenon may be linked to changes in the Arctic due to global warming.
However, there is ongoing debate among scientists regarding this theory, making it one of the major unresolved issues in mainstream climate science, as Swain pointed out.
In light of the recent occurrence of Hurricane Hilary, climate scientist Dr. Francis emphasizes the rarity of such a storm.
However, he also warns that we can expect to witness equally peculiar and devastating events in the future, as the global temperature continues to rise and the El Nino phenomenon intensifies. Dr. Francis’s statement underscores the urgent need to address the issue of climate change and its impact on extreme weather events.
As the Earth’s climate system becomes increasingly unstable, it is crucial for governments, organizations, and individuals to take proactive measures in mitigating the effects of global warming and adapting to the changing environment.
By implementing sustainable practices, investing in renewable energy sources, and promoting international cooperation, we can strive to minimize the destructive consequences of these anomalous weather patterns and safeguard the well-being of future generations.
In October of last year, esteemed hurricane scientist Kerry Emanuel from MIT delivered a guest lecture at UCLA, focusing on the increasingly rare occurrence of tropical storms or hurricanes hitting Los Angeles.
Through the utilization of computer models that accounted for climate change and other relevant factors, Emanuel discovered that a storm capable of depositing a staggering 15.7 inches (40 centimeters) of rain on downtown Los Angeles used to have a probability of one-in-108 years, at least until 2010.
However, the likelihood of such a storm has now increased to a one-in-30-year chance, according to his calculations.
Emanuel emphasized that the heightened probability of storms like Hilary today is not solely attributable to climate change. He noted that El Nino, a climate pattern characterized by warming sea surface temperatures in the Pacific Ocean, tends to amplify hurricane activity in the region.
Furthermore, when storms like Hilary strike, the warmer air holds more moisture, resulting in increased rainfall, as highlighted by Corbosiero, Swain, and Emanuel.
Numerous studies have indicated a global trend of tropical cyclones becoming increasingly rain-laden.
These findings underscore the urgent need to address the complex interplay between climate change, El Nino, and the intensification of tropical storms.
As hurricane activity becomes more frequent and rainfall intensifies, coastal cities such as Los Angeles and New York City face a heightened risk of devastating flooding events.
It is crucial that policymakers and communities take proactive measures to mitigate the potential impacts of these increasingly severe weather phenomena.
By investing in infrastructure resilience, implementing sustainable land-use practices, and fostering international cooperation to reduce greenhouse gas emissions, we can strive to safeguard our cities and protect vulnerable populations from the escalating threats posed by climate change.
According to Corbosiero, an expert in meteorology, the eastern Pacific hurricane basin is expected to be quite active for the next two to three weeks. This prediction aligns with the fact that the peak season for hurricanes in this region usually occurs towards the end of the month.
However, Corbosiero also suggests that there might be a brief respite in early to mid-September, where other weather and climate conditions may provide a temporary break in the hurricane activity.
Nevertheless, this lull is anticipated to be short-lived, as the region is likely to experience an increase in hurricane activity once again towards the end of the following month.
This information highlights the dynamic nature of weather patterns in the eastern Pacific hurricane basin and underscores the need for ongoing monitoring and preparedness.