Tropical Cyclone Freddy - which is threatening communities in Madagascar and Mozambique for a second time in as many weeks - could become the longest-lasting storm of its kind on record, the World Meteorological Office (WMO) said on Tuesday.
WMO continues to monitor the "remarkable" tropical storm, which has cut a destructive path across the two countries since it first developed a month ago.
At least 21 people have been killed, and thousands more displaced, with the latest deaths reported in Madagascar on Monday.
Major impact
"Freddy is having a major socio-economic and humanitarian impact on affected communities. The death toll has been limited by accurate forecasts and early warnings, and coordinated disaster risk reduction action on the ground - although even one casualty is one too many," said Dr Johan Stander, WMO Services Director.
Tropical Cyclone Freddy developed off the North Australian coast, becoming a named storm on 6 February. It then crossed the entire South Indian Ocean before slamming into Madagascar on 21 February, and then Mozambique three days later.
The storm brought heavy rains and flooding over several days before looping back towards the Mozambique Channel, picking up energy from the warm waters along the way, and then moving towards the southwestern coast of Madagascar.
Death, displacement, destruction
Freddy is now moving away from the area but is expected to intensify as it again heads towards Mozambique, according to the latest trajectory, which warns of heavy rains in the next 36 hours. The storm could make landfall at the end of the week, although the forecast is still too uncertain.
The UN's humanitarian affairs office, OCHA, on Monday reported that four people have died in Madagascar due to the latest rains, bringing the overall death toll there to 11. More than 3,100 people have been displaced and over 3,300 houses were flooded or destroyed.
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Meanwhile, 10 deaths have been reported in Mozambique, which was already experiencing flooding from heavy seasonal rains prior to the storm. The authorities estimate some 1.75 million people have been affected and over 8,000 displaced.
A humanitarian operation is currently underway in the region, with further challenges expected once Freddy makes landfall again.
'Remarkable' and 'rare'
"Meteorologically, Freddy has been a remarkable storm," WMO said in a press release, adding that its journey across the entire Indian Ocean and onto Madagascar "is very rare".
Freddy has also set the record for having the highest accumulated cyclone energy (ACE) of any southern hemisphere storm in history, according to the US space agency NASA, referring to the index to measure the total amount of wind energy associated with a tropical cyclone over its lifetime.
WMO continues to keep an eye on whether the storm will become the world's longest lasting tropical cyclone. The current record holder, Hurricane/Typhoon John in the Central Pacific, lasted 31 days in 1994.
"At this time, it does appear to be a new record holder for 'longest-lasting' recorded tropical cyclone...but we are continuing to monitor the situation," said Randall Cerveny, the agency's Weather and Climate Extremes rapporteur.
