During the afternoon UTC hours of May 7, 2017, Tropical Cyclone "Donna" became the strongest May cyclone ever to hit the southern hemisphere. Donna peaked at 118.7 knots (220 km/h / 136 mph) at 19:32 UTC on May 7, before it started weakening. Vanuatu Meteorology and Geohazards Department reported estimated gusts close to the center reached as high as 300 km/h (186 mph).
At 12:00 UTC on May 8, Severe Tropical Cyclone "Donna" had maximum sustained winds of 203 km/h (126 mph) close to the center, according to the RSMC Nadi, Fiji, the authority for this part of the world. This placed Donna on the upper edge of Category 3 hurricane equivalent on the Saffir-Simpson hurricane wind scale.
Tropical Cyclone "Donna" threat map by RSMC Nadi, Fiji on May 8, 2017
Donna wreaked havoc on Vanuatu, forcing people to hide in evacuation centers, strong houses, and caves. Currently available damage reports mention Torba Province as the most affected area. A significant number of houses were totally destroyed and the majority of houses damaged. For detailed preliminary reports, please visit this page: Severe Tropical Cyclone "Donna" swirling near Vanuatu
Tropical Cyclone "Donna" forecast track by JTWC on 15:00 UTC on May 8, 2017
Tropical Cyclone "Donna" at 12:00 UTC on May 8, 2017. Credit: JTWC/SATOPS, Himawari
Tropical Cyclone Donna on May 8, 2017. Credit: NASA/NOAA Suomi NPP/VIIRS
Tropical Cyclone "Donna" (18P) formed northeast of Vanuatu on May 3, 2017, 3 days after the official end of the 2016/17 South Pacific Cyclone season. Donna was initially expected to pass directly over or along Vanuatu, but the forecast track changed and Donna took a more southerly track. Still, the system brought extremely dangerous weather to Vanuatu and New Caledonia.
Shortly before 12:00 UTC on May 7, Donna's maximum sustained winds reached 95 knots (176 km/h / 109 mph), tying it with Tropical Cyclone "Nadu" in 1986 for strongest May South Pacific (E of 135°E) tropical cyclone on record. Around 14:30 UTC, Donna's maximum sustained winds reached 115 knots (213 km/h / 132 mph) which made it the strongest May southern hemisphere tropical cyclone on record.
On the same day, Donna was a hurricane for 4 days in a row which made it the longest-lived southern hemisphere tropical cyclone of the 2016/17 season to date.
By 16:00 UTC on May 8, Donna has generated the most Accumulated Cyclone Energy for any southern hemisphere tropical cyclone forming this late in the season on record, according to CSU Meteorologist and tropical cyclones specialist Philip Klotzbach.
Donna peaked at 118.7 knots (220 km/h / 136 mph) at 19:32 UTC on May 7, before it started weakening. This made it a Category 4 hurricane equivalent on the Saffir-Simpson scale. By 14:30 UTC on May 8, its maximum sustained winds were 105 knots (194 km/h / 121 mph) and the system is expected to continue weakening before it exists the Vanuatu-New Caledonia region toward New Zealand.
At 15:00 UTC on May 8, JTWC said Tropical Cyclone "Donna" is expected to weaken further as it tracks east of New Caledonia due to cooler sea surface temperatures and land interaction. After 15:00 UTC on May 9, the system will begin extratropical transition as it interacts with a major shortwave trough and baroclinic zone. Rapid weakening is expected after 03:00 UTC on May 10 due to strong vertical wind shear and cold sea surface temperatures.
Featured image credit: NASA/NOAA Suomi NPP/VIIRS. Acquired: May 8, 2017.