Monday, August 17, 1998

WEATHER UPDATE

Sorry about not updating the site on Sunday, but as you know we had a bit of a setback on our way around the world. After a terrifying descent within a thunderstorm, Steve has been recovered from the water and the dream of a global flight was nipped off, with success in sight. I'd like to provide a brief statement on that thunderstorm.

During the last 8 hours or so, we sent out four or five statements regarding the probability of impending thunderstorms ahead, but at no time was there any consideration for aborting. Flying around the world in a balloon will always involve taking gambles, and flying through some weather will be one of them. Perhaps nine times out of ten a balloon flying near 30,000 feet MSL will just fly past a cell, with little or no problem. This is due to the inherent outflow pattern in the upper reaches of a thunderstorm that, in effect, push the balloon away. And dropping down low to park was not an option, since the loss of time would have brought the balloon back up in an unacceptable northward flow pattern. So, several hours before the encounter I sent out messages on possible scenario regarding flying through the very top of a thunderstorm, and unfortunately this is what transpired. But warning about it is not necessarily enough to do anything about it. A thunderstorm is created by relatively warm air rising into cooler air. As such, the outflow out the top of the cell is not as cold as the ambient air, or the air that the balloon is flying in. When the relatively cool balloon moves into the warmer air, it sinks, and sinks rapidly. In so doing, it falls down into the guts of the thunderstorm. The velocities involved in the fall would make it very difficult, if not impossible, to compensate for that loss of buoyancy. Once into the storm, the strong wind shear and general violence within the thunderstorm complete the destruction. The bottom line is that a cloud cell of maybe 5-10 miles in diameter offset the achievements of a flight that covered over half a globe. And, it was on the extreme north edge of a thunderstorm cluster to further rub it in. A major disappointment, but a flight that proved that a manned balloon can fly around the world, as there's little doubt in my mind that aside from that brief moment, the balloon would have reached Argentina, to complete the elusive global flight.

This is the last meteorological statement of the flight, so I'd like to take the time to thank all of you that read this space, and especially those that took the time and effort to drop us e-mail responses. It was a great achievement for Steve, but with a heart breaking finish. But, a safe finish.

Bob Rice
Chief Meteorologist

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This page was updated August 17, 1998 19:35 UTC websolo@wunder.wustl.edu