After blasting Guam on Wednesday with gusts over 100 mph and more than two feet of rain, Typhoon Mawar has rapidly gained strength and become 2023′s most intense storm. It’s also stronger than any storm that formed in 2022.
President Biden declared Guam a major disaster area and ordered federal aid to help support local recovery efforts in areas affected by Mawar beginning May 22, according to a White House statement released Thursday.
Called typhoons in the northwest Pacific Ocean, these storms are no different from hurricanes in the Atlantic Ocean with respect to how they form and their effects. When typhoons attain peak winds of at least 150 mph, they are called super typhoons.
Mawar struck Guam as a typhoon, but was a super typhoon before striking the island and has since regained that intensity.
Mawar’s effects on Guam
Despite significant wind damage and flooding, early reports by Guam’s local government indicate that no fatalities or major injuries occurred.
Late Thursday local time, Gov. Lou Leon Guerrero (D) issued an “all clear” for Guam in a video posted on Instagram, indicating that the island had successfully weathered the storm. “We now continue to focus our efforts on repairing infrastructure and restoring services to residents,” she said.
A boil water notice remains in effect for Guam after system failures during the storm, as much of the island is still without running water. The Guam Power Authority has begun the process of reestablishing power across the island, focusing on critical infrastructure and other key areas to start. All but 1,000 of the electricity provider’s 52,000 customers lost power at the height of the storm.
Roadways are reopening, with some blocked by debris. Gas stations have reopened in parts of the island as well. Guam International Airport remained closed to commercial traffic, as cleanup of the facility and humanitarian flights continue.
Wind damage across the island was widespread, with many trees downed onto buildings and roadways, especially in the northern half of the island.
Scenes from around Tumon Bay, #Guam the day after #typhoon #mawar - lots of tree damage, power and water out, hum of generators everywhere, immediate shoreline battered by surge and some cars shunted around by wind pic.twitter.com/BsSmcDV9He— James Reynolds (@EarthUncutTV) May 25, 2023
Rainfall was as bad or worse than forecast as the storm moved across the island very slowly, causing hours of torrential rain piling up as much as two feet or so.
Guam International Airport picked up 9.53 inches Wednesday, making it the wettest May day on record there, according to National Weather Service data. The airport saw at least 14.43 inches between May 22 and 25. Normal rainfall for the month there is 3.31 inches.
Other locations saw even more rain. Maximum totals include 28.42 inches in Dededo, 27.23 inches at Mount Chachao and 23.12 inches at Andersen Air Force Base on the northern tip of the island.
An ocean surge and near-shore waves up to 20 feet also battered parts of the area.
Rapid intensification of the storm resumes
Meteorologists say that while Mawar was a formidable storm when it struck Guam, it could have been much worse. The storm’s peak winds dropped notably on approach to the island, falling from 155 mph (135 knots) before it struck Guam to 105 mph (91 knots) on its closest approach.
True indeed! Closest approach to #Guam came at a minimum, perhaps as a 90 kt typhoon (equivalent to a CAT 2 hurricane). #Mawar https://t.co/HdjcJIYU2h pic.twitter.com/bvuYd3gHTH— Greg Postel (@GregPostel) May 25, 2023
The main cause was a well-timed eyewall replacement cycle, a process in which the ring of powerful thunderstorms around the storm’s center degrades while a surrounding area of storms takes over.
“What happened in the evolution of the core of Super Typhoon #Mawar was nothing short of a miracle for the small island of Guam,” wrote meteorologist Mike Ventrice on Twitter.
After pulling away from Guam, Mawar began to rapidly intensify again, its peak winds jumping up to 175 mph. Scientists have found that such instances of rapid intensification have become more frequent in recent decades, because of rising ocean temperatures spurred by human-caused climate change.
Short-term forecasts from the Joint Typhoon Warning Center project that maximum winds could peak at around 180 mph before a gradual weakening trend begins.
Environmental conditions are expected to remain conducive for an extreme storm system over the next several days.
Once tropical cyclones reach Mawar’s current intensity, sustaining such strength is difficult, however. There may be additional eyewall replacement cycles that could temporarily weaken the system.
The Japan Meteorological Agency forecasts the storm to see its lowest pressure drop to 905 millibars this weekend, which would place Mawar among the strongest storms on record in the region so early in the season. Generally, the lower a storm’s pressure, the stronger it is.
The storm will approach the northern Philippines and Taiwan in about five days, but in a weakened state. Regardless, potential for flooding rain, damaging storm surge and high winds exists in both countries. Rainfall in particular could be extreme given an expected slowing of the storm as it approaches.