Every year, hurricane season is dreaded by everyone living in the Caribbean, Mexico and the USA, as well as by those planning to spend their vacations on the islands. Martinique is no exception. We explain everything you need to know about hurricanes and how to plan your vacation.
What is a hurricane?
A hurricane is a type of storm, also known as a tropical cyclone, which forms in tropical and subtropical regions of the globe at ocean level.
Hurricanes originate in the Atlantic Basin, which includes the Atlantic Ocean, the Caribbean Sea, the Gulf of Mexico and the Pacific Basin, notably in the eastern North Pacific Ocean and, more rarely, in the central North Pacific Ocean. The hurricane season begins on June 1st and ends on November 30th, although hurricanes can occur outside this period. The peak of the Atlantic hurricane season is September 10th, with most activity occurring between mid-August and mid-October.
An updated list of names is maintained by the World Meteorological Organization to identify these storms. If a storm causes the death of at least one person, its name is permanently withdrawn and will not be reassigned at all.
Several meteorological study centers monitor these phenomena to study them and understand their mechanisms, but above all to warn populations of the trajectory so that they can prepare in advance. The main study center is the U.S. National Hurricane Center. They track phenomena from their inception until they have completely dissolved, and report their forecasts to the governments of the territories potentially affected.
Aircraft are also sent to the heart of storms to assess their strength and obtain essential data. See graph opposite.
By default, the NHC predicts 12 events per year, but the number may change depending on various factors.
So what are these factors?
According to the NHC, hurricanes are formed by 6 factors:
- One of the first factors to consider is water temperature. When ocean waters are above 26 degrees Celsius (79 degrees Fahrenheit), hurricanes form, and more are numerous if such temperatures persist for several days, weeks or months. Below 26 degrees, they fail to form.
A major problem is that these ocean temperatures are common in the tropical East Pacific and tropical Atlantic. They frequently exceed this threshold, resulting in the formation of around 12 phenomena per year.
- The second ingredient is distance from the equator. Without the Earth's rotation and the resulting Coriolis force, there would be no hurricanes. As the Coriolis force (the force that allows the Earth to turn on itself) is greatest at the poles and virtually nil at the equator, hurricanes can only form in the area close to the equator (5 degrees latitude). The Coriolis force generates a counter-clockwise rotation of low pressure in the Northern Hemisphere and a clockwise rotation of low pressure in the Southern Hemisphere.
- The third element is a saturated slip-rate gradient near the storm's center of rotation. A saturated slip rate ensures that latent heat will be released at a maximum rate. Hurricanes are warm-core storms, and the heat generated by hurricanes comes from the condensation of water vapor rising by convection around the eyewall. When the skidding rate is unstable around the cyclone's eyewall, it ensures that the rising air parcels continue to grow and condense water vapor.
- One of the major and not insignificant factors is low vertical wind shear, particularly in the upper layers of the atmosphere. Wind shear is a variation in wind speed with height. Strong winds aloft destroy storm structures by moving warm temperatures over the eye and limiting the vertical accentuation of air parcels. Hurricanes only form if winds aloft are not too strong.
- The fifth cause is the presence of high relative humidity from the surface to the middle levels of the atmosphere. Dry air in the middle levels of the atmosphere hampers hurricane development in two ways:
- First, dry air causes liquid water to evaporate. The evaporation process promotes cooling and thus reduces the structure of the hurricane's hot core.
- Secondly, dry air in the middle levels can create a trade wind inversion that reinforces the heat and dryness in the middle levels of the atmosphere.
- The final cause is the presence of a tropical wave. Atlantic hurricanes often begin with a thunderstorm complex moving off the coast of Africa. This becomes what is known as a medio-tropospheric wave. If this wave meets the favorable conditions mentioned in the first 5 elements above, it amplifies and develops into a tropical storm or hurricane. In the eastern Pacific, hurricanes can form from a medio-tropospheric wave or a monsoon trough.
How do you get through a hurricane?
When a hurricane crosses a landlocked area, i.e. an uninhabited zone, the main danger for the population is the strong waves and swells that make the sea dangerous and impassable for any activity such as swimming, fishing or water sports.
People are warned several days before, with a forecast that will be refined as the event gets closer. They should be sure to stock up on food, as stores will remain closed until authorized by the authorities. In some cases, it's advisable to stay indoors and protect windows to prevent them from being blown out or damaged by the force of the wind, or becoming projectiles.
Dans la situation d'urgence il est possible de procéder à l'élagage des arbres afin d'éviter des dégâts majeurs sur les câbles électriques ou des dommages sur les habitations.
Avant le passage de la tempête tropicale, le territoire est placé en vigilance jaune, orange, rouge et violet
Le passage de l'ouragan commence toujours par des vents de plus en plus puissants visibles aux mouvements des arbres. Puis arrivent les pluies qui se renforcent au fur et à mesure du passage sur le territoire. Parfois l'électricité est coupée soit en raison d'une panne centrale ou alors les poteaux électriques ont subi les frais de la tempête.
In an emergency, trees can be pruned to avoid major damage to power cables or damage to homes.
Before the passage of the tropical storm, the territory is placed under yellow, orange, red and violet vigilance.
The passage of a hurricane always begins with increasingly powerful winds, visible in the movement of trees. Then comes the rain, which intensifies as it passes over the territory. In some cases, electricity is cut off, either because of a power failure or because power poles have been damaged by the storm.
But we survive! If you're sheltered and follow the safety instructions, there's no risk! On the other hand, surfing, getting close to the coast to take selfies or videos, or going out, makes you a potential victim.
The passage of a hurricane generally lasts only a few hours, especially on a small territory like Martinique. When it is no longer over land, the authorities warn the population in the media about what they can and can't do to ensure safety.
If a power pole is on the ground, it can be dangerous, and only the professionals from the power grid services should intervene. They will be on the job for several days until electricity is restored to all users.
Water distribution may also be disrupted, and it may take several days in the worst-case scenario for drinking water to be restored. It is therefore essential to stock up on water supplies before the storm hits.
State services will also intervene to clear roads in the event of falling trees.
Crop conditions are also closely monitored, as Martinique is one of France's biggest exporters of bananas and sugarcane products.
The authorities quickly declared a state of natural disaster, so that emergency funds could be released. A full estimate of losses was made. Reconstruction was financed by European, national and local funds.
Generally speaking, Martinique quickly returned to its normal way of life. This is because the population is cleaning up quickly, and the services of the communes and the Communauté Territoriale de la Martinique will be mobilized until everything is back to normal. It's worth noting that neighboring islands don't have the same financial, logistical and professional resources, so they're taking longer to recover from the damage. As Martinique is French, it will quickly be able to call on the help of its Guadeloupean and Guyanese neighbors at first, and then, if necessary, on the arrival of men and equipment from France.
Après le passage d'un ouragan, il est recommandé d'attendre plusieurs jours avant de se baigner à la mer à nouveau. Les effets des tempêtes tropicales ne se font pas ressentir que sur la terre, elles sont nombreuses aussi dans les océans et les mers. Les forts ont souvent agi sur les fonds marins mais également les sables et les algues.
L'eau paraît souvent sale après le passage d'un ouragan.
Aussi de la même manière que les vagues et la houle sont fortes avant le passage d'une tempête tropicale, elles le sont encore après. Il faut attendre l'annonce du retour au retour annoncé par les autorités pour envisager la pratique à nouveau de toute activité marine. Concernant le secteur de la pêche, il est fortement impacté. Les populations marines étant impactées par l'ouragan ont pu se créer un nouveau lieu de vie. Les pertes seront également évaluées dans le total des dommages causées par le passage de la tempête.
After a hurricane, it's advisable to wait several days before swimming to the beaches again. The effects of tropical storms are felt not only on land but in large numbers in the oceans and seas. The strong winds have often acted on the seabed, but also on sand and algae.
Water often looks dirty after a hurricane.
Just as waves and swells are strong before a tropical storm, they are even stronger afterward. We'll have to wait for the authorities to announce a return to normal before we can contemplate the resumption of any marine activity. The fishing industry has been hard hit. The marine populations impacted by the hurricane have been able to create a new living environment. Losses will also be included in the total damage caused by the storm.
Should you give up your Caribbean vacation during hurricane season?
The answer, of course, is NO! So far, it's impossible to predict that a hurricane will hit your destination precisely. Likewise, it's impossible to know the strength of a hurricane months in advance, when people usually book their summer vacations. Even at the last minute, a hurricane may very well increase or decrease in strength, depending on the various factors mentioned above, or even change course. When observatories forecast a certain phenomenon several months in advance, it's impossible to know for sure whether it will be a hurricane or simply a tropical wave. While we're aware of the dangers, we mustn't panic in advance.
The number and strength of hurricanes depend on many factors and vary from year to year. If, on the other hand, a hurricane is forecast one or two days before your departure, then YES, we advise you to postpone. After all, no one goes on vacation to be in a place hit by a natural disaster. You can obtain refunds for expenses already incurred from your credit card company (Visa, Mastercard) or directly from the accommodation you booked in advance.
One essential thing to know is that in the tropical zone, rain is frequent, and outside the hurricane season you can also come to a Caribbean island and experience momentary torrential downpours and gray skies for several days. Once again, these rainy episodes cannot be predicted several months in advance.
If you're out and about and you see a heavy tropical downpour, there's no need to cancel your plans for the day, as the rains can last for just a few minutes, with the sun shining right afterward. As the saying goes, "After rain comes fair weather".
In the case of short rains, swimming is not a danger, but it is advisable to avoid rivers where rain can cause you to fall onto the rocks. Whatever happens, keep informed about weather conditions before and during your stay.
As a final reminder, the last category 5 hurricane to devastate Martinique was Hurricane Dean in 2007. No direct casualties were reported.
See you soon!