Lightnin' ponders the skies, OR what's up with storms these days?

Factual Questions
1

Over this last weekend, Austin’s had a series of good thunderstorms. Last night was particularly good- lots of lightning, little rain. I like it like that.

Anyway, we’ve all heard that saw about how to tell how far a stroke of lighting is; count the seconds, multiply by five (?), and that’ll tell you how many miles away it was. So last night I saw a stroke directly overhead, and I started counting.

According to the number I got, the stroke was a good fifteen miles away. What the heck? It was directly over head- and I’ve NEVER heard of an thunderhead being fifteen miles high!

What’s up with that?

There are a few things I can conjecture:

  1. The air was thin up there- too thin to be displaced sufficiently violent enough to generate a thunderclap. What I heard was from another, ground-based stroke.
    Seems unlikely, though- the air wouldn’t be THAT thin up there, would it?

  2. There was some sort of inversion layer between the lightning stroke and my tender ears- and the shock wave (read thunder) bounced off of it.
    Also unlikely- the storm had things fairly churned up, atmosphere-wise. I doubt an inversion layer could’ve maintained integrity with all that wind blowing.

  3. How YOU doin’, Opal?

So, which is it? What is it? Why is it?

2

Is this how you figured it? That’s the problem then–you’re supposed to divide by 5. What you’re really doing when you do that is using the speed of sound to figure out how far away the bolt is. You can assume the flash of lightning is essentially instantaneous. Sound travels about a mile every 5 seconds–so every five seconds you count, the sound has traveled a mile–divide by 5.

In that case, it looks the bolt was more like .6 miles away, not 15.

3

See, there’s yer trouble, you obviously were observing metric lightning.

4

Boy is my face red…

But the question still stands… Was that lightning directly overhead actually 1/6th of a mile away? Why was it so much quieter than the other lightning?

Many times I’ve seen directly above lightning be completely silent, while a storm on the horizon makes ominous rumblings…