After hitting Guam on Wednesday, Super Typhoon Mawar became one of the strongest tropical cyclones on record in May.
For a time on Friday, May 26, Mawar howled with maximum sustained winds of 185 miles per hour. This made it the strongest storm of 2023 so far. It is also stronger than any of the 2022 tropical cyclones. With gusts approaching 210 miles per hour, Mawar pushed waves nearly 65 feet high, according to the Joint Typhoon Warning Center.
A sweeping view of Super Typhoon Mawar rolling into the Western Pacific as a Category 5 storm on May 26, 2023, as seen by the Himawari-9 satellite. (Credit: CIRA/CSU and JMA/JAXA)
Mawar is our planet’s fifth-largest Category 5 storm in 2023, just below the 1990-2022 average of 5.3 for a the whole calendar year.
“This is an unusually high number of these strongest tropical cyclones for so early in the year,” says meteorologist Jeff Masters. “With the most active part of the Northern Hemisphere tropical cyclone season ahead, 2023 could have a chance to challenge the record of 12 Cat 5s in a year, set in 1997.”
The eye of Super Typhoon Mawar, seen on May 24, 2023 by the Himawari-9 satellite. (Credit: CIRA)
The satellites provided breathtaking views of Mawar. The close-up animation of Mawar’s eye above is an example of this. Acquired by the Himawari-9 satellite on May 24, it reveals a phenomenon known as the “stadium effect”, which is sometimes observed during strong tropical cyclones. It’s a feature of the eyewall – the vertical wall of intense thunderstorms that surrounds the relatively calm eye, which is typically about 25 to 40 miles in diameter.
With the stadium effect, towering eyewall clouds curve outward from the surface with height. The appearance resembles a sports stadium seen from above.
Features called “mesovortices” are also visible. These mini-cyclones are often found in the eyes of intense tropical cyclones. The wind speed inside can be up to 10% higher than in the eyewall.
Links to climate change
Although it has been difficult for scientists to quantify the effect of global warming on tropical cyclones like Mawar, a few trends have become increasingly clear.
The global proportion of major tropical cyclones – Category 3, 4 and 5 storms – has likely increased over the past 40 years, according to the most recent report of the Intergovernmental Panel on Climate Change. (These storms sustained winds of 111 mph or more.) So does the frequency of rapidly intensifying storms.
According to the IPCC, there is also “strong confidence” that human-caused climate change has contributed to an increase in intense rainfall from tropical cyclones. This is partly because a warmer atmosphere can hold more moisture.
Additionally, the IPCC notes that the rate at which tropical cyclones move across the surface has likely slowed, with evidence showing that anthropogenic climate change has contributed to this effect, at least in the United States. This allows storms to linger longer over a given area, leading to greater rainfall and the potential for catastrophic flooding.
Forecast for Mawar
After hitting sustained winds of 185 mph on Friday May 26, Mawar began to weaken experiencing a phenomenon known as ocular wall replacement cycle. When this happens, a new eye grows around the old eye.
Once eyewall replacement is complete, the storm is expected to re-intensify slightly as it moves over warm seas, according to the Joint Typhoon Warning Center. In about three days, as Mawar approaches the vicinity of the Philippine Islands, he will be traveling over colder seas and is expected to weaken.
The storm could threaten the island nation, then possibly Taiwan. But at this point, its trajectory is uncertain. Time will tell us.