Unusually Warm Sea Produces Deadly Cyclone in the Bay of Bengal
100,000 people may die in the aftermath of a single cyclone,
making it the deadliest storm on record.
Still, aid is slow to come…
Late on Friday, May2, 2008, a deadly cyclone struck Myanmar near the densely populated Irrawaddy River Delta—the country’s main rice-growing region. Dubbed “Nargis,” the storm brought gusts of up to 155 mph and some 20 inches of rain, and passed within 30 kilometers of Yangon, the nation’s largest city and former capital. In addition to wind and rain, a 12-foot storm surge inundated 50% of low-lying homes in an area occupied by nearly 2.5 million people. In the end, Friday’s cyclone is estimated to have killed at least 20,000 people—and there are suggestions that this number may yet rise considerably. It left a million more homeless, without food and water
Nargis first developed on April 27 as an area of deep convection over the Bay of Bengal. Under the influence of high pressure centered to the northwest, it tracked northwest along the high’s periphery, developing slowly. Nargis was initially expected to make landfall somewhere in southeast India or Bangladesh. It stalled on April 28 due to high pressure from the southeast. Strong subsidence from both high pressures and subsequent drying caused it to weaken.
As the southern high took over, Nargis resumed its motion. On May 1st, a trough approached from the west and the storm began to re-intensify, taking a more northeasterly track. Nargis finally made landfall around 12:00 UTC with maximum sustained winds of 127 mph and a radius of maximum winds of approximately 33 miles. It passed just north of Yangon with winds of 80 mph.
The North Indian Ocean generates about four tropical cyclones each year. But, over the last 30 years, there has been a significant increase in the number of Category 4 and 5 storms (Saffir-Simpson Scale). For example, during the period 1975-1989, there was only one such storm, representing 8% of the total number of tropical cyclones during that period. During the subsequent 15 year period (1990-2004), there have been seven such storms, or 25% of the total.
Last year alone saw two such intense storms. Sea-surface temperatures in the North Indian Ocean have increased about 0.4°C over the last 30 years. This year, water temperatures in the Bay of Bengal during the last week of April, when Nargis was forming, were already over 30°C, about one degree warmer than normal.
While Nargis has no significant insurance implications, it is a humanitarian disaster. Today, five days after the storm made landfall, aid is arriving slowly. The U.N.’s World Food Program began distributing food in damaged areas of Yangon late Tuesday, but the coastal regions and the hard-hit Irrawaddy River Delta remain largely cut off due to flooding and road damage. Buddhist monks have joined residents and soldiers in clearing roads of fallen trees. Still, some cyclone-ravaged areas are only accessible by boat, and relief groups worry that towns like Pyinkaya (population 150,000) in the southwest of the delta region have received no aid at all since the storm hit.
.MGW.
Leave a Reply