Cyclone Sidr Is Only the Latest Big Storm in North Indian Ocean Basin

It has been a heck of a hurricane season for the North Indian Ocean basin.

First, in June, we saw Category 5 Cyclone Gonu, the most intense storm ever recorded in the Arabian Sea. Gonu struck Oman and Iran – nations with little experience of hurricanes – and caused some $ 4 billion in damage. The storm is now known as the worst natural disaster in the history of Oman.

Unisys Weather

But of course, there was worse still to come. Cyclone Sidr – which may have also been a Category 5 storm, although officially it was right at the cutoff between categories – devastated Bangladesh last week with a powerful storm surge in a highly populous low-lying region. The death toll stands at around 3,000 at the moment, and may rise as high as 10,000 or even (by some estimates) 15,000. Already, Sidr is the deadliest tropical cyclone disaster since 1998's Hurricane Mitch killed 11,000 in Nicaragua and Honduras. Let's hope it doesn't surpass it.

Meanwhile, a humanitarian crisis is unfolding before our eyes. Just read the various news reports: Nearly a million families have been affected, an unimaginable number of homes have been destroyed, the rice crop is decimated, shrimp farming is obliterated. And we have no idea how bad it's going to get before the situation in Bangladesh stabilizes and starts to improve. Sidr brings home just how deadly hurricanes can be, especially in parts of the developing world.

Moreover, if you consider Gonu and Sidr together, the North Indian basin has not seen so busy a year since 1999, when the Bay of Bengal hosted both a Category 4 and a Category 5 storm. But frankly, given that Sidr was really probably a Category 5 just before landfall, you could easily argue that the basin has had its worst year on record for intense hurricanes in 2007.

What it all underscores is the importance of keeping a global perspective – both in a humanitarian sense (especially as Thanksgiving approaches) but also in a meteorological sense. In 2007 just as in 2006, the United States didn't experience any serious hurricanes – and so of course, people have been slamming the pre-season forecasts and questioning whether dire prognostications of worsened storms due to global warming are justified.

But if we look past our own part of the world, we quickly see that hurricanes have been very busy. It's not as if global hurricanes suddenly went quiet; it's just that we've been relatively lucky in the Atlantic since 2005. But if hurricanes are getting worse, there is going to be a lot of resultant pain in developing countries, like Bangladesh. Given the devastation just caused by Sidr, that's a truly wrenching thought.

And Speaking of Keeping a Global Perspective: Look to the Southern Hemisphere.

It may well be the case that Cyclone Sidr will be the last super-intense hurricane that we'll have to worry about in the northern hemisphere in 2007. The Atlantic has quieted down, probably for good; ditto for the Northeast Pacific. Only in the highly active Northwest Pacific basin do we regularly see strong typhoons in December.

Meanwhile, the Southern Hemisphere is already starting to awaken, with the formation of three named storms in the past week in the Australian (or Southwest Pacific) and Southeast Indian Ocean basins. Cyclone Bongwe, currently spinning to the south of the island of Diego Garcia, may soon become the equivalent of a Category 1 or even Category 2 hurricane. And we may see some still-more intense hurricanes south of the equator soon enough, especially if anything forms in the super-warm band of ocean water near the Solomon Islands, depicted below:

Atlantic Oceanographic and Meteorological Laboratory

I don't want to bet on anything bad happening to our friends from the South in the next few weeks. However, I'll just note that unless there are three more category 4 and 5 hurricanes in the remaining weeks of this year – which seems increasingly unlikely - my very risky prediction of 18 such storms in 2007 will be proven wrong.

When you think about how much damage just one such storm – Sidr – caused, that sounds like a very good thing.