Hurricane season has just started and it will be above normal, warns NOAA

The season hurricanes in the North Atlantic begin each year on the 1^er June to end on November 30. The 2021 season was marked by 21 hurricane phenomena including 7 hurricanes. The major phenomenon of 2021, Hurricane Idacategory 4 out of 5, had been responsible for 97 deaths and had caused significant damage in Louisiana and Mississippi.

In the Last update of its forecasts for the hurricane season in the North Atlantic, the National Oceanic and Atmospheric Administration (the NOAA ; in French: the American Agency for Oceanic and Atmospheric Observation) predicts a particularly active 2022 season. NOAA estimates a 65% chance of an above-normal hurricane season, with a non-negligible risk that it will be extremely active. The probability that the season is simply within normal is 25% and only 10% that it is below. If NOAA forecasts are confirmed, it will be the 7^e consecutive year with an abnormally active season.

The number of hurricane phenomena could be double the normal

What is a normal hurricane season? This is a season that corresponds to the 1991-2020 average, i.e. 10 to 12 phenomena on average with 7 hurricanes including 4 major ones. Remember that in 2020, the season had been a recordwith 31 phenomena, including 14 hurricanes and 7 major ones!

For 2022, the American organization predicts 14 to 21 phenomena in all, with 6 to 10 hurricanes (from 119 km / h), including 3 to 6 major with winds above 179 km/h. It should be noted that these figures refer to the number of cyclone phenomena which could form at sea, but that does not necessarily mean that these will then necessarily touch land and do damage: many cyclonic phenomena make their trajectory in the ocean without threatening the coasts.

But it only takes one tropical storm or one hurricane to touch earth to cause significant destruction and sometimes casualties. The list of the first 21 names attributed to cyclonic phenomena is already ready, with the possibility that it will not be enough if the total number were higher.

More cyclones in the Atlantic and less in the Pacific

In addition to the global warming of the oceans linked to human activityanother parameter comes into play: La Ninathis climatic phenomenon which is characterized by colder than average water in part of the Pacific, unlikeEl Nino which is associated with warmer than average water in this area.

This parameter has consequences on the climate of part of the world, and particularly on the development and intensity of cyclones. Whether La Nina is known to cause a very active hurricane season in the North Atlantic (Antilles, United States), it generally results in a calmer season with regard to the phenomena of the central Pacific (Mexico): 2 to 4 hurricanes are planned for this year in the central Pacific.

The conditions are in place for more intense hurricanes in 2022!

Article of Karine Durandpublished on April 24, 2022

American research organizationsatmosphere all agree that the Atlantic hurricane season, which begins in June, will be intense with around 20 phenomena forecast including 8 to 10 hurricanes. Here’s why.

After two particularly active years in matter of activity cyclonic, the 2022 season promises to be violent again in the North Atlantic. Between 1991 and 2020, there were 10 to 12 hurricane phenomena per year on average, of which 7 hurricanes, including 3 majors. However, in 2021, 21 phenomena formed, generating 7 hurricanes, including 4 major ones. Even if the 2021 season was remarkable, it did not reach the record figures of the year 2020, with 31 phenomena, including 14 hurricanes and 7 major ones!

Just over a month before the official start of the hurricane season in the North Atlantic (from June to November), the forecasts of the various American reference organizations in the study of the climate have been updated. Their projections are clear: the conditions for 2022 are looking very similar to those of 2021, but not as exceptional as those of 2020.

The Climate Adaptation Center and The Weather Company predict an average of 20 to 22 hurricane phenomena, including 8 to 10 hurricanes, including 4 to 5 major ones. Accuweather and Colorado State University expect just under 20 events (16 to 20), a lower number than other agencies, but still significantly above the average of the past 30 years. In recent years, in addition to an increase in the number of hurricane phenomena, we have observed a lengthening of the hurricane season: while it is supposed to start in June, phenomena have begun to form as early as May every years since 2015.

Climatic conditions are met for more intense phenomena

Two climatic parameters explain these alarmist forecasts for the 2022 season: water temperature very high in the Gulf of Mexico, the main fuel for the formation of hurricanes, and the persistence of the La Niña phenomenon. In some areas of this gulf, the water temperature is currently 4°C above seasonal averages: it locally reaches 27°C, a temperature that could already allow the formation of hurricanes, in the middle of the month of april !

Another parameter to take into account, climatic phenomena El Nino and La Nina which occur in phases of one to two years. These phenomena are characterized by anomaly temperature of part of the waters of the Pacific Ocean: La Niña occurs when the water is colder than average, conversely we speak ofEl Nino when the water is warmer than average. The consequences of an El Niño or La Niña year are strongly felt on the climate of many countries, and on the cyclone phenomena in the Atlantic which are more numerous with La Niña.

The latest projections estimate that La Niña should persist throughout the summer, before weakening in the fall. During a La Niña phase, the wind shear aloft is weaker, allowing tropical storms — the stage of the tropical phenomenon which occurs before that of the hurricane — to rise very high and thus to strengthen. El Niño, on the other hand, causes much more wind shear, which limits the growth of tropical storms.

With these two parameters, the abnormally warm water of the Gulf of Mexico and the persistence of the La Niña phenomenon, a simple depression that would form in the ocean increases its chances of rapidly strengthening into a hurricane.