Bavi stronger, faster than Sinlaku as forecasters watch another potential weather system

Super Typhoon Bavi packed stronger winds than Super Typhoon Sinlaku but moved through the Marianas much faster, reducing the duration of destructive conditions across Guam, Saipan and Tinian, according to a preliminary assessment by National Weather Service Guam meteorologist Brandon Aydlett.

While damage assessments—particularly on Rota—are still underway, forecasters are also keeping a close watch on another weather disturbance that could develop next week as the El Niño pattern continues to favor tropical cyclone activity in the western Pacific.

Speaking to Marianas Press via Zoom on Tuesday morning, July 7, Aydlett said weather conditions across the Marianas were steadily improving after Bavi moved away from the region, allowing officials to begin recovery efforts.

Although some passing showers and gusty winds remain possible, typhoon warnings have been lifted and tropical storm conditions are no longer expected, he said.

Aydlett stressed that the assessment remains preliminary because meteorologists are still collecting and analyzing data, particularly from Rota, which took the direct hit from the Category 5 super typhoon.

"We're still receiving wind data from the Saipan airport," he said, noting that observations confirmed minimum typhoon conditions on Guam and Saipan while a final estimate of Rota's peak winds will depend heavily on damage surveys.

"I think determining the final wind speed on Rota will ultimately be based on a forensics estimate and assessment of the damage," Aydlett said. "Looking at the structural damage... what does the infrastructure, whether it's telephone power line poles that went down or the wooden poles... that's all going to be very helpful in understanding just what happened."

One of the biggest differences between Bavi and Sinlaku, he said, was how quickly Bavi moved across the region.

"The speed of motion of Sinlaku was extremely slow, around 5 miles per hour," Aydlett said. "Super Typhoon Bavi was moving a bit faster, anywhere from 10 to 13 miles per hour, and so that really significantly reduced the duration of impacts across the Marianas."

Despite Bavi producing stronger winds than Sinlaku over Guam, vegetation fared noticeably better because the island spent far less time under tropical storm conditions.

Aydlett explained that Guam experienced roughly 18 to 24 hours of tropical storm-force winds during Bavi, compared with 48 to 60 hours during Sinlaku, which stripped much of the island's vegetation despite being the weaker storm.

He also noted that Sinlaku's wind field was larger—roughly 500 to 600 miles across—while Bavi's tropical storm wind field measured about 400 to 500 miles in diameter, further limiting the duration of damaging winds. Bavi, however, reached an estimated intensity of 175 to 180 mph at Rota, compared with Sinlaku's estimated 150 mph when it crossed Tinian and Saipan.

Even as communities focus on recovery, Aydlett urged residents not to let down their guard.

Forecasters are monitoring Invest 97W in eastern Micronesia, though he emphasized it is still too early to determine whether it will develop into a tropical cyclone or threaten the Marianas.

"I wouldn't say don't be too alarmed just yet," he said. "It is something to watch, to be aware of, not necessarily to act on yet."

Still, he said the ongoing El Niño pattern means residents should expect an active season.

"This year is an El Niño year, and we were already anticipating a busy year for tropical cyclones," Aydlett said. "Get your personal readiness back up, but focus full bore on the recovery from Bavi."

The National Weather Service will continue monitoring long-range weather models and said it will provide timely updates if the developing disturbance becomes a credible threat to the Marianas.