high lightning activity?

[Gregory Kaeser]

Hi Everyone!

At first, my English is very bad (i speak German), i have never learned in School. I understand much, but with write i has large trouble. I hope you understand me and give me some credit. Thanks.


One Asks employs me much: From where comes the very high frequency with lightning??

A impressive example: http://www.youtube.com/watch?v=wYy3BbRwW1s&feature=related

We know: Within clouds warm water droplets rise while cold ice crystals sink. When particles, such as these, collide they transfer electrons leaving some of the particles positively charged and others negatively charged. Due to the forces of updrafts and gravity these opposing charges become separated leading to the production of an electric field (Wahlin, 1989)

Simply said (i is not completely correct): Therefore strong thunderstorms would have to produce many lightnings.
In my years, where I chase thunderstorms, however many strong thunderstorms were not at all lightning active.

What reasons gives also for high Lightning activity?
- Cosmic Ray? (Mariachi - Wikipedia information )
- other one??

I now, it is not a simple Question. What are your Experiences/Assumptions ?

Thanks already for your Answers.
Greetings from Switzerland
Gregory

 

[Wes Carter]

Here is my assumption and it might be totally wrong (And if I am please correct me):

I've always thought that in supercell storms the shear often seperates the updraft and downdraft enough to isolate the rising and falling water droplets/ice crystals which can limit the amount of lightning.

It seems to me that the popup afternoon thundershowers in the summer (especially in the South) are more prolific lightning producers. Some of these become pulse severe storms but almost always produce a ton of lightning.

Another thing I've noticed is HP supercells tend to produce more lightning than LP or classic supercells. Has anyone else noticed this or is it just my limited experience?

 

[Skip Talbot]

Another thing I've noticed is HP supercells tend to produce more lightning than LP or classic supercells. Has anyone else noticed this or is it just my limited experience?

Yes, however, I've also seen LPs produce impressive CG strikes, probably very powerful postively charged strikes.

Another observation I've seen is that the lightning tends to increase when the dewpoint depression decreases.

 

[Arjan van Beelen]

One of the most important aspects in lightning formation is the graupel content (ice mass) of the cloud. Storms with a larger graupel content tend to have more lightning activity (at least that's the current hypothesis I'm trying to validate). Graupel (ice) content seems to be well correlated with the dBZ lapse rate and temperature profile. Storms with high reflectivity above -10C tend to have a lot of lightning activity. Remember the warm tropical airmass above Oklahoma in 2007? The storms were producing a lot of rain, but very few flashes. Supercells tend to have large flash rates because of their broad updraft, great vertical extention and lower temperatures (than tropical convective storms) aloft. They have much larger ice content than tropical thunderstorms.

 

[Mike Smith]

Very complicated issue. Andover tornadic supercell had almost no CGs while Greensburg's had nearly continuous CG's.