Hurricane Melissa, which has recently impacted both Jamaica and Cuba, has become emblematic of the increasing frequency and intensity of major storms in a warming world.
Historically rare devastating storms characterized by extreme winds and heavy rainfall are now becoming more frequent, a trend accelerated by climate change. This shift is revealing intriguing patterns in the behavior and timing of these formidable hurricanes.
Before making landfall in Jamaica as a powerful Category 5 storm, Melissa, similar to other hurricanes over the past decade, exhibited exceptional strength in warmer waters. This rapid intensification has marked it as a major force of the current Atlantic season, tying it for the most formidable landfall recorded in Atlantic history.
After impacting Jamaica, the storm weakened and delayed rainfall—another indication of how climate change influences hurricane behavior. Notably, Melissa’s occurrence came later in the season, demonstrating a shift as hurricane activity typically peaks in early September, but this year persisted into the fall when ocean temperatures remain elevated.
Experts suggest that these patterns signify a new normal for hurricanes with Melissa representing this change.
“This storm differs significantly from those observed in previous decades,” stated Shel Winkley, a meteorologist affiliated with the Climate Central research group.
This is a critical change that meteorologists and officials in hurricane-prone areas are vigilantly observing.
intensified all at once
One of the most striking features of Melissa is its extraordinary rate of intensification. In a mere 18 hours, it escalated from a tropical storm to a Category 4 on Sunday, achieving Category 5 status early Monday morning.
Climate change is heightening the likelihood of such “rapid intensification,” defined by the National Hurricane Center as an increase in wind speeds of 35 miles per hour or more within a 24-hour timeframe.
In Melissa’s case, Winkley noted that notably warm sea surface temperatures in the Caribbean, coupled with elevated atmospheric moisture, triggered “extremely rapid intensification.”
“We’ve become adept at predicting significant increases in hurricane intensity, but Melissa surpassed even our most optimistic forecasts regarding wind speeds,” he explained.
Winkley added that the storm traversed Caribbean waters that were 2.5 degrees Fahrenheit above average, with climate change making its occurrence up to 700 times more likely.
“While 2.5 degrees Fahrenheit might seem minor, such small variations can noticeably impact storm behavior,” Winkley stated.
A number of recent hurricanes have exhibited rapid intensification. For instance, Hurricane Milton’s wind speeds surged by 90 miles per hour in roughly 25 hours, and Hurricane Ian in 2022 experienced rapid strengthening prior to making landfall in Florida. Similar patterns were observed in Hurricanes Idalia in 2023, Ida in 2021, and Harvey in 2017.
If there are fewer hurricanes, the impact will be greater.
Over the past 35 years, the annual incidence of hurricanes and tropical cyclones has decreased.
“Our research indicates that the number of hurricanes, including typhoons, around the globe has significantly dropped since 1990,” remarked Phil Klotzbach, a hurricane researcher at Colorado State University.
However, this overall decline is largely attributed to a reduction in Pacific cyclone activity, Klotzbach noted. In contrast, Atlantic hurricane activity has seen an increase primarily due to a long-term La Niña effect, which tends to weaken the upper-level winds that inhibit hurricane formation.
“If you enjoy hurricanes, La Niña is beneficial for the Atlantic,” Klotzbach said.
If a hurricane forms, it is increasingly likely to develop into a significant storm due to rising ocean temperatures.
“We’ve observed a rise in the frequency of hurricanes reaching categories 4 and 5,” Klotzbach noted.
Melissa was the third Category 5 hurricane to form this year, marking the first instance in two decades where two or more such hurricanes occurred in a single season.
Zachary Handros, an atmospheric scientist at the Georgia Institute of Technology, explained that warmer oceans will likely contribute to increased hurricane activity moving forward; however, atmospheric changes may alter upper-level winds, potentially hindering some storms. “It’s not a straightforward answer,” he added.
The ongoing evolution of these trends is a subject of active research and scientific inquiry.
Hurricane season gets longer
Experts concur that this season’s top hurricane struck just days before Halloween.
“At this point, we are quite late in the season, and typically things should be easing,” remarked Derrick Herndon, a researcher at the University of Wisconsin’s Tropical Cyclone Research Group.
While the Caribbean has always been known for powerful late-season hurricanes, Klotzbach indicated that the likelihood is increasing. He recently submitted a peer-reviewed study suggesting that hurricane seasons may commence earlier.
Klotzbach noted that the pattern of fall hurricanes is influenced by a long-term swing toward a La Niña pattern, likely a result of both climate change and natural variability.
La Niña diminishes upper-altitude winds while Caribbean waters remain warm, facilitating storm formation into late October and early November. “The odds are stacked for a powerful hurricane,” he said.
Hurricane Melissa further complicated matters with warmer-than-usual ocean waters off Jamaica’s southern coastline.
“If we anticipate a particularly strong Atlantic hurricane, it is likely to develop in this region,” Herndon stated.
In previous years, such storms would generally pull up cooler waters from the depths, thereby limiting their growth. However, with ocean heat surging both at the surface and at depths of 60 meters, Melissa has been able to tap into increased heat and energy, according to Andy Hazelton, a hurricane modeler and associate scientist at the University of Miami’s Oceanic and Atmospheric Cooperation Institute.
the storm is stagnant
Research indicates that hurricanes are more prone to stalling just before or after making landfall, resulting in significant rainfall. This conclusion has been supported by a study published last year. Other research suggests that the overall forward speed of storms has decreased, but this remains a topic of debate.
Following this pattern, Hurricane Melissa gained strength before stalling offshore from Jamaica. On Tuesday morning, the day of its initial landfall, the storm was traveling at a mere 2 miles per hour. Forecasters anticipated up to 30 inches of rain in some areas of Jamaica, surpassing one-third of the yearly average.
The scientific community remains divided regarding why certain storms slow down, though some hypothesize that climate change may be weakening atmospheric circulation patterns.
Hurricane Harvey in 2017 vividly illustrated the consequences of such stalls, as the storm lingered over Houston, leading to rainfall of nearly 5 feet in some locations. This phenomenon is especially concerning as a warmer atmosphere can retain and release more moisture.
“For every degree Fahrenheit that the environment warms, the atmosphere can contain 4% additional moisture,” Winkley stated. “Rising ocean temperatures amplify not only the strength of hurricanes but also enable greater evaporation, resulting in more moisture available for these storms to absorb and then release.”
Source: www.nbcnews.com
