Tropical Cyclone Activity in the Southern Hemisphere: February 2025
In late February 2025, multiple tropical cyclones were active simultaneously in the South Pacific and Indian Ocean. Notable storms included Cyclones Rae, Alfred, Seru, Bianca, Honde, and Garance. Warnings and preparations were issued as these cyclones varied in intensity and posed risks to land due to their proximity and forecasted wind speeds.
In late February 2025, a rare phenomenon occurred with tropical cyclones active in both the South Pacific and the Indian Ocean. The VIIRS sensor on the NOAA-20 satellite captured a false-color image on February 26, revealing five tropical cyclones. This technology utilizes brightness temperature infrared signals to differentiate between cooler cloud structures and the warmer surfaces below.
On February 25, Tropical Cyclone Rae weakened after affecting Fiji with heavy rainfall. At the same time, Cyclones Alfred and Seru were located in the South Pacific. Cyclone Seru achieved temporary Category 1 strength, while Alfred was expected to remain offshore yet still pose hazardous coastal conditions for southern Queensland.
Hitting Category 2 on the day of the satellite image capture, Alfred was forecast to escalate to Category 4 on February 27. Meanwhile, Tropical Cyclone Bianca off Western Australia downgraded to tropical storm status after peaking at Category 3 but stayed distant from land, minimizing impacts for mainland Australia and nearby island communities.
In the Indian Ocean, Cyclones Honde and Garance were more threatening to land. Mauritius, located east of Madagascar, closed its airport as Cyclone Garance approached, which was expected to intensify from Category 2 to Category 3, with wind speeds reaching 190 kilometers (120 miles) per hour. Cyclone Honde, ranked as Category 1, threatened southern Madagascar with heavy rains, strong winds, and significant storm surge.
The proliferation of these storms is attributed to warm sea surface temperatures and weak wind shear conditions in the region. A marine heat wave persisted off Western Australia since September 2024, with above-average sea temperatures contributing to the increased storm activity. Meteorologists anticipated a higher likelihood of severe tropical cyclones this season, aligned with the typical cyclone season in the Southern Hemisphere, which spans from November through April.
This report highlights the unusual occurrence of multiple tropical cyclones in the Southern Hemisphere in February 2025, noting their locations, strengths, and potential hazards. Meteorological factors like warm sea temperatures played a crucial role in the cyclones’ development, emphasizing the need for awareness in regions affected by these storms.
Original Source: earthobservatory.nasa.gov
