Cyclone Giovanna threatens Madagascar, “massive destruction” possible

Extremely dangerous cyclone Giovanna, equivalent to a category 4 hurricane, is set to make landfall on the east coast of Madagascar today. The powerful storm contains maximum sustained winds of 145 mph (125 knots) and may produce extensive damage on this island off the southeastern coast of Africa.

Satellite imagery reveals a storm with a well-defined eye, excellent symmetry and deep convection around its core. Its outer bands are already lashing the coast and the eye should move ashore late today.

Concerns are mounting about the toll the storm may afflict on this relatively poor country, especially as it may target highly populated areas. John Uniack Davis, Madagascar’s director for the humanitarian organization CARE, told the United Nations news agency IRIN that if the storm center moves just south of the coastal port of Toamasina “it has the potential to cause massive destruction.”

AccuWeather’s Jesse Ferrell, reviewing the history of storms to strike Madascar, found that Giovanna’s track most closely remembles cyclone Geralda from 1994. That storm “destroyed 80% of the city’s seaport Toamasina.” IRIN news said Geralda “killed about 200 people, displaced 40,000 and affected another 500,000.”

In addition to the destructive category 4 intensity winds, a large storm surge and 4-8” or more of flooding rain are also likely with this storm. Wunderground’s Jeff Masters notes an elevated risk of damage relative to past storms due to deforestation over the last 30 years, which will worsen runoff from flood waters.

As Giovanna crosses Madagascar, it will weaken considerably before it re-emerges over the water late Tuesday or early Wednesday. It is then forecast to strike Mozambique as a tropical storm or depression late this week.

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