Cyclone Nargis had all the makings of a perfect storm

Forecasters began tracking the cyclone April 28 as it first headed toward India. As projected, it took a sharp turn eastward, but didn't follow the typical cyclone track in that area leading to Bangladesh or Myanmar's mountainous northwest.

Instead, it swept into the low-lying Irrawaddy delta in central Myanmar. The result was the worst disaster ever in the impoverished country.

It was the first time such an intense storm hit the delta, said Jeff Masters, co-founder and director of meteorology at the San Francisco-based Weather Underground. He called it "one of those once-in-every-500-years kind of things."

"The easterly component of the path is unusual," Masters said. "It tracked right over the most vulnerable part of the country, where most of the people live."

"When we saw the (storm) track, I said, 'Uh oh, this is not going to be good," said Mark Lander, a meteorology professor at the University of Guam.