Hurricane Season

Figure 3: Satellite image of Hurricane Beryl as a category 4 storm off the coast of Grenada 1^st July 2024 © NASA Johnson Flickr

Hurricane Beryl increased in strength after leaving St Vincent and the Grenadines, reaching wind speeds of 165 mph on 2^nd July and was classified as a Category 5 storm – the highest category in the Saffir-Simpson Scale. 

It slowed to a Category 3 storm as it passed the southern coast of the island of Jamaica with wind speeds of 195km/h (120 mph). This left approximately 400,000 people in Jamaica without power and claimed two lives. In addition, storm surges and heavy rain caused localised flooding of houses, roads and farmland with an estimated $6.4 million worth of destroyed food crops and farming infrastructure resulting in food shortages. Jamaican authorities prepared for the storm by imposing a curfew and closed main airports whilst the storm passed on Wednesday 3^rd July. Nearly 1,000 Jamaicans sought refuge in shelters that evening.

The Cayman Islands were spared the full force of the Hurricane as it passed to the south, however, storm surges and heavy rainfall still affected the Islands.  

Hurricane Beryl moved over Mexico’s Yucatán Peninsula as a category two storm on Friday 5^th July. Although the tourist spots of Cancún and Tulum experienced heavy rain, felled trees and power shortages, no other damage was reported. Before the arrival of the storm, schools were shut, tourists evacuated (including 3,000 from Holbox Island). Over 8,000 troops from Mexico’s military were deployed to the Yucatán Peninsula to help support the area. 

By 8^th July, Beryl moved onto south-east Texas and Louisiana in the United States as a Category 1 storm bringing with it high winds, 38 cm of rain, and storm surges. Over 1,000 flights from Houston were cancelled with travellers encouraged to rearrange their flight plans over the following days. Ports were shut and over 2 million homes and businesses were left without power in and around the city of Houston.  

This strength of hurricane has come so early in the season because of two factors: ocean heat content and La Niña. The combination of these two things could bring twice as many hurricanes this season compared to others. 

As sea temperature plays a vital role in the formation of tropical storms and both 2023 and 2024 have had higher than average sea temperatures, forecasters were able to predict, with a certain degree of confidence, that 2024 would be an above-average year with more frequent and stronger storms. The sudden increase in sea temperatures over the past 18 months is still being researched, however, there is a possibility that it could be due to increased warming in the atmosphere and have a connection to climate change.

In 2023, the Atlantic region was experiencing an El Niño event. It is this event that was thought to have been part of the reason storms weren’t as abundant in 2023 even though the sea temperature was high. The increased wind shear generated in El Niño events can hamper the formation of tropical storms or reduce their intensity in the Atlantic by blowing thunderstorms away from its centre or tilting its cylindrical vortex, disrupting the ideal heat engine that usually allows storms to form.

With building evidence, scientists believe that a La Niña event could quickly follow the descending El Niño period. However, like many weather phenomenon, it is very hard to predict and the evidence is still inconclusive. A La Niña event has the opposite effect to El Niño in the Atlantic effectively increasing the chance of storms to form and build into stronger hurricanes. Therefore, if La Niña is present in the Atlantic this year, there is more chance of a larger than average storm season in the Atlantic.