Malawi, Madagascar and Mozambique are reeling from the results of Tropical Cyclone Freddy.

Greater than 400 individuals have been killed and hundreds of houses destroyed.

Freddy has been one of many longest-lived storms ever recorded within the Southern Hemisphere, if not the entire world.

Southern Africa is commonly battered by cyclones and tropical storms coming in from the Indian Ocean however Freddy was completely different for a number of causes.

Freddy has lastly been declared over by the French Meteorological service. The storm was named by the Australian Bureau of Meteorology on 4 February and and eventually got here to an finish on 14 March.

It was robust sufficient to be formally labeled as a tropical system for at the very least 36 days.

Nevertheless, we have to watch for affirmation by the World Meteorological Group earlier than we will say whether or not it’s formally the longest-lasting recorded storm.

What’s fascinating about Freddy is how far it has travelled. It started its journey off the coast of north-west Australia, crossing the Southern Indian Ocean from east to west, one in every of solely 4 storms in historical past to take action.

The basic method of measuring the energy of a storm is by its wind velocity. At its strongest Freddy was the equal of a Class 5 hurricane with winds in extra of 160mph (260 km/h).

Thankfully, it was most intense over open waters.

Freddy broke the report for all-time accrued cyclone power (ACE) within the Southern Hemisphere, a measure of the storm’s energy over time, beating the earlier report, set by Cyclone Fantala in 2016.

It was additionally the primary storm within the Southern Hemisphere to endure 4 separate rounds of speedy intensification – this is a rise within the most sustained winds of a tropical cyclone of at the very least 30 knots in simply 24 hours.

Since landfall, rainfall quantities have exceeded 600mm (24 inches) in some areas with torrential rains resulting in mudslides in susceptible areas.

With hurricane-force winds, the storm additionally introduced massive storm surges because it stored re-energising over the nice and cozy waters of the Mozambique Channel.

A Tropical Cyclone within the Indian Ocean is stronger than a tropical storm.

Freddy first hit Mozambique as a average tropical storm. Its second landfall in Mozambique was as a Tropical Cyclone and by the point it reached Malawi, it had weakened to tropical storm energy – though that it the place it brought on most destruction.

Freddy has now damaged up, however its remnants are nonetheless inflicting rain throughout components of Mozambique and Malawi which may worsen the flood scenario.

They’re all large storms however how they’re outlined is dependent upon the place they’re shaped. Within the Atlantic and East Pacific they turn out to be hurricanes, within the West Pacific they’re typhoons and within the Indian Ocean and close to Australia they’re referred to as cyclones.

This can be a tough query to reply as Freddy is definitely uncommon.

We have seen this sort of storm beforehand when we now have seen a robust or persistent La Nina climate sample within the Indian Ocean. The Bureau of Meteorology has simply declared the tip of a sequence of back-to-back La Nina occasions which started in September 2020.

By way of local weather change, it is a well-known undeniable fact that hotter air can maintain extra water so the quantity of rain which fell, particularly throughout its time over land, is prone to have been enhanced by local weather change.

Hotter waters within the oceans maintain extra power, so it follows that these storms could nicely turn out to be extra energetic with time and have the ability to unleash much more rainfall.

Speedy intensification is extra seemingly with increased sea temperatures and so the truth that this occurred a number of occasions could have been partly as a consequence of local weather change. The sluggish motion of the storm at occasions, particularly simply earlier than the second landfall in Mozambique, may be associated.