In a rare meteorological event, six tropical cyclones churned across the South Pacific and Indian Oceans simultaneously in late February 2025.
These powerful storms, captured in stunning satellite imagery, varied in intensity, with some dissipating and others intensifying into dangerous systems. While some stayed offshore, others, like Garance and Honde, threatened island nations with fierce winds, torrential rains, and storm surges.
Twin Ocean Cyclone Surge
In late February 2025, two different oceans were teeming with tropical cyclones. At one point, three storms were active in the South Pacific — a rare but not unprecedented event. Meanwhile, another three cyclones churned in the nearby Indian Ocean.
A false-color satellite image (above) captured on February 26 by the NOAA-20 satellite’s VIIRS (Visible Infrared Imaging Radiometer Suite) sensor reveals five of these storms. The image uses infrared signals, known as brightness temperature, to highlight cooler cloud structures in white and purple, contrasting them against the warmer surface in yellow and orange. Just a day earlier, a sixth storm, Tropical Cyclone Rae, was weakening east of the image area after bringing heavy rainfall to Fiji.
South Pacific Cyclones on the Move
In the South Pacific, Cyclones Alfred and Seru hovered near Rae. Seru remained offshore from Australia, briefly strengthening to a Category 1 storm on the Saffir-Simpson scale. Alfred, also projected to stay offshore, was expected to generate dangerous coastal conditions in southern Queensland, according to the Australian Bureau of Meteorology. At the time of the image, Alfred had reached Category 2 intensity but would escalate to Category 4 by February 27.
Off Western Australia, Tropical Cyclone Bianca was on the tail end of its journey, having weakened to tropical storm status on February 26. The previous day, it had intensified to Category 3 but stayed far enough from land that mainland Australia and island communities were not expected to feel its effects.
Indian Ocean Storms Threaten Islands
Bianca’s Indian Ocean cohabitants, Honde and Garance, posed more hazards to land. The island nation of Mauritius, east of Madagascar, shut down its airport on February 26 as Garance approached, according to news reports. The storm would strengthen from Category 2 that day to Category 3 the next, with wind speeds of 190 kilometers (120 miles) per hour. Meanwhile, Honde skirted south of Madagascar as a Category 1 storm. Heavy rain, strong winds, and storm surge were forecast for central and southern Madagascar, Mauritius, and Réunion island.
Ocean Conditions Fuel Cyclone Surge
Meteorologists noted that warm sea surface temperatures and weak wind shear conditions may have contributed to the proliferation of storms. A marine heat wave has lingered off of Western Australia since September 2024, and anomalously high sea surface temperatures warmed in the area in late February 2025. For the South Pacific, the Australian Bureau of Meteorology had predicted a higher-than-average likelihood of severe tropical cyclones this season due to expected warm ocean temperatures. Tropical cyclone season generally runs from November through April in the Southern Hemisphere.
NASA Earth Observatory image by Michala Garrison, using MODIS and VIIRS data from NASA EOSDIS LANCE and GIBS/Worldview and the Joint Polar Satellite System (JPSS).
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
1 Comment
“At one point, three storms were active in the South Pacific — a rare but not unprecedented event.”
OK, so it is a rare event. What is the implication of a rare event, besides not being seen frequently? Shouldn’t one expect to see an increase in low-probability random events when the observation time increases?