Freddy: The cyclone that lasted more than a month
- March 17, 2023
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Image source, EPA
Malawi, Madagascar and Mozambique are suffering from the effects of Tropical Cyclone Freddy.
More than 400 people were killed and thousands of homes were destroyed.
Freddy was one of the longest-lived storms ever recorded in the southern hemisphere, if not the world.
Southern Africa is often hit by hurricanes and tropical storms that blow in from the Indian Ocean, but Freddy was different for a number of reasons.
How long did Freddy last?
Freddy has finally been declared over by the French Weather Service. The storm was named by the Australian Bureau of Meteorology on February 4th and eventually ended on March 14th.
It was strong enough to be officially classified as a tropical system for at least 36 days.
However, we’ll have to wait for confirmation from the World Meteorological Organization before we can say if it’s officially the longest-lasting storm on record.
The interesting thing about Freddy is how far he has travelled. It began its journey off the coast of north-west Australia and crossed the southern Indian Ocean from east to west, one of only four storms in history to do so.
How powerful was Storm Freddy?
The classic way to measure the strength of a storm is wind speed. At its strongest, Freddy was a Category 5 hurricane with winds in excess of 160 mph.
Luckily it was most intense over open water.
Freddy broke the record for all-time accumulated cyclone energy (ACE) in the southern hemisphere, a measure of the storm’s strength over time, beating the previous record set by Cyclone Fantala in 2016.
It was also the first storm in the southern hemisphere to undergo four separate rounds of rapid intensification — an increase in the maximum sustained winds of a tropical cyclone of at least 30 knots in just 24 hours.
Since landfall, rainfall levels have exceeded 600 mm (24 inches) in some areas, with torrential downpours causing mudslides in vulnerable areas.
With gale force winds, the storm also brought large storm surges as it reignited over the warm waters of the Mozambique Channel.
What is the difference between a cyclone and a tropical storm?
A tropical cyclone in the Indian Ocean is stronger than a tropical storm.
Freddy first hit Mozambique as a moderate tropical storm. Its second landfall in Mozambique was a tropical cyclone, and by the time it reached Malawi it had weakened to tropical storm strength – although that’s where it caused most of the destruction.
What will Storm Freddy do next?
Freddy has since dissipated, but his remains are still causing rain in parts of Mozambique and Malawi, which could exacerbate the flood situation.
What is the difference between a cyclone, a typhoon and a hurricane?
They are all giant storms, but how they are defined depends on where they originate. They become hurricanes in the Atlantic and Eastern Pacific, typhoons in the Western Pacific, and cyclones in the Indian Ocean and near Australia.
Was Storm Freddy caused by climate change?
This question is difficult to answer because Freddy is certainly unusual.
We have seen this type of storm before when we have seen a strong or sustained La Nina weather pattern in the Indian Ocean. The Bureau of Meteorology has just declared the end of a series of consecutive La Nina events that began in September 2020.
Regarding climate change, it is a known fact that warmer air can hold more water, so the amount of precipitation, especially during its time over land, has likely been increased by climate change.
Warmer water in the oceans contains more energy, so these storms can certainly gain energy and release even more precipitation over time.
Rapid intensification is more likely with higher sea temperatures, and the fact that this has occurred multiple times may be due in part to climate change. The storm’s slow movement at times, particularly just before the second landfall in Mozambique, could also be related.