Puzzling Electric Hurricanes

SpaceAdmiral writes "Hurricanes seldom have lightning because they primarily consist of horizontal winds (as opposed to vertical winds). However, three of the biggest storms of 2005 (Rita, Katrina, and Emily) had plenty of lightning and NASA has an interesting write-up about it." Bottom line is "we still have a lot to learn about hurricanes."

Comments

Katrina had lightning indeed

[Jon Abbott]

The same day that Katrina was nearing Louisiana, I got a picture of lightning from a feeder band in Jacksonville, Florida -- over 500 miles away. The picture was shot with a Canon Powershot S2 (albeit in video mode -- I cheated by extracting the single frame that had lightning).

Re:Dorothy hit by lightning

[Rei]

You don't need some revolutionary lightning-causing *method* (and in fact, that wouldn't really work - read below, and I'm sure you'll spot why).

In real thunderstorms, you have strong updrafts at high (cold) altitudes. You get several types of ice; among these are snow an graupel (ice pellets). Static between them creates small charge differences; the graupel tends to become negative and the snow positive. Were that all that was going on, that would be the end of the story, except that there's a sorting mechanism going on. The graupel is denser and falls down, while the snow is light and blows up. Now the charged particles are *very* far apart; discharges can't happen easily. So, charges build up, and up, and up, and eventually you get lightning. As the ground is more positive than the negative cloud bases, you can get cloud to ground lightning if the path is easier than the path up to the tops of the clous.

Basically, what this means in the context of these hurricanes is that there were strong updrafts in cold air (even though this is a tropical system) - probably extremely high altitudes.