When most people think about tropical cyclones, Africa usually doesn’t come to mind. Idai — a Category 2-equivalent with 100 mph winds — will make landfall in Mozambique later this week.
The storm formed 40 miles off the shore of Mozambique early Saturday, drifting east-southeast over the Mozambique Channel during the day just above the tropical storm minimum threshold. Things didn’t stay that way for long, though. Between 2 a.m. Sunday and 2 a.m. Monday Mozambique time, Idai exploded from 45 mph to 105 mph, going from just above low-end tropical storm strength to a high Category 2 within 24 hours. It became a major hurricane-equivalent (Category 3) just six hours later. Storms in the Indian Ocean are called “cyclones.”
That fits the bill for “rapid intensification,” strengthening at a greater rate than Harvey, Irma, Florence or Michael did before impacting the United States. After peaking at 120 mph, Idai’s winds stand at 105 mph, but it could restrengthen.
The worst of the storm hasn’t moved over land — yet.
Idai is in a warm, low-shear environment with sea surface temperatures of around 30 degrees Celsius, Phil Klotzbach, a tropical weather researcher at Colorado State University, told The Washington Post, noting that such conditions are ripe for the storm to maintain its intensity or even strengthen. "That environment is likely to continue for the next couple of days,” he said.
Mozambique is bracing for the storm’s arrival late Thursday into Friday. The Joint Typhoon Warning Center is calling for winds of roughly 120 mph with gusts to 150 mph as it tracks west, likely making landfall just north of Beira, Mozambique’s fourth-largest city. Forecasters say 8 to 12 inches of rain could accompany Idai’s heavy tropical feeder bands. March is Beira’s wettest month, averaging just under a foot of rainfall.
The city might also see a storm surge threat, depending on where the eye moves ashore. Just north of where the storm center makes landfall, inundations of 1-3 meters (or up to 10 feet) above mean sea level can be expected.
Idai’s drift toward Madagascar over the weekend brought heavy rain to the island nation of 25 million. In the community of Sambava, on the northeast tip of the island, 8.7 inches have come down since Sunday. Another 6.3 inches have fallen in Majunga in the past two days.
Madagascar is no stranger to tropical cyclones, last hit by Ava in January 2018. The storm displaced more than 17,000 with devastating floods and killed 29.
Ten months earlier, Enawo made landfall on the island’s northeast shore immediately after peaking as a strong Category 4-equivalent. Ninety-six died in the storm, which caused $50 million in damage. Madagascar’s infrastructure is susceptible to tropical cyclones, with the nation’s $12.5 billion gross domestic product ranking No. 132 in worldwide economies, according to the IMF.
The southwest Indian Ocean is cranking out more activity than normal for the 2018-19 cyclone season. Klotzbach tweeted that the season has had more than twice the average number of “major” cyclones.