Wednesday, September 09, 2009


It's night and the sun has set, but I keep thinking I see a red glow in the distant sky. My peripheral vision catches it and I look up and then I don't see it anymore. Is the the city lights on low cloud? Westjet flights going into land with really bright anticollision lights? An afterimage on my retinas from the dashboard screen I'm staring at? It's not the moon showing through clouds, because it's close to a new moon, so it wouldn't have risen yet, and it wouldn't be that bright.

It could be distant lightning, but it's teasing me, as it's never quite visible when I'm looking that way.

There was a forecast for 30 percent probability of thunderstorms at 04 Zulu, but the sky was still clear at sunset. Now it's dark, so I can't see if anything is building. I call flight services and ask them if there is any forecast precipitation or obscuration below ten thousand in the next three hours. I've discovered that not everyone knows you can do that: ask the briefer to interpret the TAF for you instead of just reading it. If he read it, I could either filter it through my brain as it came, discarding everything that wasn't what I was interested in, or I could write it all down and then interpret the parts I wanted. But that takes up more air time and this is simpler for me. Let the briefer throw out anything irrelevant to me before I hear it. And the briefers aren't robots. If there's a hazardous condition unrelated to the information I've asked for, they'll make sure I know about it.

The thunderstorms are still forecast, but now at 05Z, just after the time I expect to be landing. And they aren't calling for fog tomorrow morning, either. There's no burst of static coinciding with the tiny flashes, so if they are thunderstorms they are quite far away.

I land, taxi in, and shut down. Finally I see the lightning, for of course it is lightning, not out of the corner of my eye. It must be getting closer, because it's more noticeable now, even among the airport lights, but it's still far enough away that I have no concerns refuelling. I park and chock for the night. Driving back in the truck I watch out the window as sheets of lightning advance in a front slowly across the prairie. I'm tucked into bed by the time the storm hits, but it bangs on the window so hard I could believe there was someone out there asking to come in.

I admit it: I originally put the electrical tag on this post purely because of the cheering I've had lately from fans of electrical posts. I was going to put a quick quip here about comparing popup CBs to CBs popping, but I googled for the rating on those CBs. A current of 50,000 A and up to a billion volts is too impressive to laugh at. Lightning is dangerous stuff. I think because I can see it from so far away, and because to an aircraft in flight other components of a thunderstorm are more dangerous, I might not be scared enough by lightning. It's more dangerous than a whole wing locker full of daisy-chained extension cords. Or a day before yesterday's painfully biting insect, which I have been advised was probably a flying ant. Still red. Still itches. I think it's getting better, though.


nec Timide said...

World wide, lightning strikes are so frequent, and so powerful that they cause the the cavity formed by the earth and ionosphere to ring with electromagnetic energy the way the buzzing of an ambasure results in the melodious tones of a trombone.

GPS_Direct said...
This comment has been removed by the author.
GPS_Direct said...

Too bad it wasn't a hopping red ant... Then you could say that "something jumped up and bit you on the... um... upper rear thigh area."

More on topic, I like the idea that CBs are so powerful they shoot lightning out the bottom and sprites out the top. I figure one day we'll come to the understanding that there's some sort of elegant balance between the charge of the ground and the charge of the atmosphere. Like they feed each other, back and forth, seeking equilibrium, but never quite getting there - all on a global scale.

swl_wildcat said...

Most aircraft seem to survive a hit.

Sarah said...

There's no burst of static coinciding with the tiny flashes, so if they are thunderstorms they are quite far away.

Thank goodness for distance.

I've no experience with thunderstorms. I'm more likely to just stay on the ground if they're forecast, not having a boss telling me to go fly with them (at night! )

So I was wondering... is the old story about the ADF being useful for listening to lightning strikes true? Will it actually point to a cluster of strikes?

I'm guessing you don't have Nexrad/XM, let alone actual weather rader. And your StrikeFinder(tm) has a old and faded "INOP" tag..

Aviatrix said...

Sarah, yes, unmistakeably. The ADF is tuned to a particular AM frequency and the antennae and circuitry conspire to make the needle point at the source of that frequency. A lightning bolt is an electromagnetic transmission on every frequency, and far more powerful than a mere NDB. At the same time as lightning static comes over the radio, every VHF-related indicator in the plane responds, and the ADF needle will swing right around momentarily.

Anonymous said...

I can see the moon out there. It's fat. It was full on Saturday night.


Aviatrix said...

Anonymous, see the Time Travel link at right. If you wanted to actually be clever you could use such clues to calculate the current lag.

SwL_Wildcat said...

If your really savvy you can figure out which company she flies for and what hardware she drives... :)