At 11pm local time on 26 September 2024 theHurricane Helene hit the Big Bend regionon the west coast of Florida, touching the city of Perry like hurricane of category 4 on the Saffir-Simpson scale with winds up to 220 km/hprovoking at least 4 victimsthousands of displaced people, 3 million buildings left without electricity, storm surges with waves up to 6 meters high and 300 mm of rain a few hours. It was the strongest hurricane to hit this region of Florida, and the third to hit this area in just 13 months. After the landfall the disturbance moved to Georgia and decreased in intensity until it was downgraded to tropical stormwith winds up to 90-100 km/h, but it remains dangerous and the alert remains high. Helene confirms that the 2024 hurricane season (which saw the violence of Hurricane Beryl at its beginning) is particularly intense, as was the 2023 season: one of the many negative effects of the climate change. One of the reasons why the hurricane was so intense, in fact, is the high temperatures of the waters of the Gulf of Mexico in the days in which the disturbance was formed, which reached i 30°C.
Helene’s trajectory
It was from September 23 that the National Hurricane Center had identified the possibility of hurricane formation in the area between the Yucatan peninsula, Mexico, and Cuba. In the following days the disturbance began to strengthen yourself, first being classified as a tropical storm – already leading to heavy flooding in the Yucatan – and then, on Thursday 25 September, as a hurricane.
Helene has arrived on the coast of Florida with acategory 4 intensitythe second highest on the Saffir-Simpson scale.
A hurricane of this category can bring winds up to 250 km/h and is capable of destroying entire buildings, uprooting trees and causing such damage to electricity as to isolate entire areas and lead to casualties.
The most impactful factor of this extreme event is that of floods. Helene touched land near the city of Perry in Florida, and in addition to bringing winds of up to 220 km/h, capable of causing extensive damage to property and people, it caused storm surges up to 6 meters high – which can cover a two-story building – e rains torrential with accumulations up to 300 mm in a few hours.
It is also a hurricane of very large radiusthe effects of which did not only affect the portion of the coast near Penny, but rather the entire internal coast of Florida and part of the Atlantic coast.
The hurricane then came headed north in the following hours, arriving in Georgia near Atlanta and is expected to move northwestward in the next few days Tennessee, where according to forecasts it will arrive with the diminished strength of a tropical storm.
However, already now after a few hours, Helene has decreased her intensity a lotmoving to category 1 and then to tropical storm. It is normal for this to happen when hurricanes make landfall. However, this is still a scenario with winds up to 100 km/h approximatelybut above all the expected rainfall is intense and therefore the risk of flooding is very high.
The state of alert in Florida and other states
There size of this hurricane – not just in terms of intensity, but also in terms of extension – led to the declaration of state of emergency in several states, including Florida, Georgia, North and South Carolina.
It was the director of the National Hurricane Center himself, Mike Brennan, who strongly urged anyone in the affected areas to attempt evacuation but only if it was safe, as they found themselves in conditions that were difficult to survive.
The counting of victims has already risen to 3but the number is unfortunately destined to rise.
Hurricane Helene is in all respects the most intense ever recorded in these areas and the fact that it developed within the Gulf of Mexico allowed it to gain strength quicklyas not only are the waters of the gulf themselves quite mild, but they also reached record highs in September of this year.
The temperatures of sea surface in Helene’s journey they have in fact reached the 30°C2 to 4 °C above normal, and this served as fuel to increase the intensity of the hurricane.
Why it was such an intense hurricane: the reason
THE’intensity of Helene and the frequency such a high rate of these phenomena in recent times can be attributed to global warming, which has among its consequences the increase from the ocean surface temperaturewith a consequent increase in the probability of these extreme phenomena.
Two months ago, in July, Central America was also violently hit byHurricane Beryl. In that case, the exceptionality lay in the precociousness of this intense hurricane, because we were at the beginning of the hurricane season. Now we find ourselves faced with another equally extreme event, which as we have said is the most intense ever recorded in the affected area. This season of hurricanes it’s revealing itself particularly intensebut unfortunately it’s something we’ll have to get used to: it is one of the many negative effects of the ongoing climate crisis.
