Raindrop Champ
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It may not rank with the splitting of the atom or the discovery that the earth is round, but the detection of an 8 mm raindrop about half the diameter of a dime -- certainly made waves among weather researchers. Hi. I'm Dave Thurlow and this is The Weather Notebook.

For years, raindrop specialists believed that the biggest a drop could get was 5 mm across, the diameter of your average hole punch. But then, in 1985, members of the Joint Hawaiian Warm Rain Project captured an 8 mm liquid monster hurtling toward Hilo on the Big Island -- and a new era in precip history began.

What went right for that lucky drop? In tropical places like Hawaii, raindrops grow inside warm clouds in the classic big fish/little fish mode: big drops swim around the cloud tops feeding on little droplets until they get fat enough to fall. The fatter they are, the faster they fall, and the faster they fall, the less competition they have on the way down. The lack of competition is crucial, because when a drop falls in the company of too many chunky rivals, it's likely to collide and shatter. That 8 mm big boy was the first one off the block, it sailed through a field of juicy little droplets that it swallowed down with ease, and it crossed the finish line glistening and intact, setting a record that still stands after 16 years.

But this dripping champion should not rest on its laurels. Theoretically it's possible for a drop to reach 10 mm before it becomes hydrodynamically unstable and splits in half. Who knows, maybe the next record-breaker is taking aim at Tahiti this very moment?

Thanks today to contributing writer David Laskin of Seattle, Washington. The Weather Notebook is a production of the Mount Washington Observatory and supported by Subaru of America, the National Science Foundation and listeners like you.