According to catastrophe modeling firm AIR Worldwide, the first tropical cyclone in the Northern Indian Ocean this season, Tropical Cyclone Mahasen, made landfall northwest of Chittagong, Bangladesh, at about 0600 UTC (2 a.m. EDT) on Thursday, May 16. As it came ashore the storm delivered torrential rain of about 250 mm or so and maximum sustained winds of up to 100 km/h (60 mph), destroying thousands of poorly constructed homes. Its arrival coincided with low tide, but storm surge still caused waist-deep flooding in some areas of this low-lying coastline. However, insured losses are not expected to be significant.
The storm’s slow approach gave authorities in Bangladesh plenty of time to prepare and to issue warnings. According to the U.N., more than 4.1 million people were at risk from the cyclone. In Bangladesh, almost 1 million people were evacuated to “cyclone-proof” buildings and other shelters. As the storm neared, several Indian states issued storm alerts and Myanmar, Bangladesh’s neighbor to the east, evacuated about 166,000 people from its northwest coast.
“Bangladesh initially identified Tropical Cyclone Mahasen as a level seven storm on its scale (out of a maximum of ten), but as it approached landfall the storm became disorganized and weakened considerably,” said Dr. Peter Sousounis, senior principal atmospheric scientist at AIR Worldwide. “Tropical Cyclone Mahasen also veered west of its predicted path, sparing the major population concentrations in the area, including Chittagong and Cox’s Bazar, and leaving India and Myanmar virtually unscathed. As a result, less damage was experienced than was anticipated.”
According to AIR, Mahasen is currently moving north-northeast at about 45 km/h (28 mph) and is expected to lose cyclone status as it continues inland and encounters rugged terrain and high vertical wind shear. The remnant system will continue to spread heavy rain into easternmost India and northern Myanmar, exposing many areas to the risk of flooding and landslides.