Tristan Gooley

So mist in the autumn, when we see mist in the morning, that is a sign that's where the coldest air is.

Cold air is denser than the mild air, so it rolls downhill.

So the morning mist in autumn is making a map of the lowest parts of the landscape for you.

If you walk down into a morning mist, you can feel the temperature change.

So what I encourage people to do is when you're first using twinkling stars to forecast weather is cheat, cheat like crazy.

Look at the forecast.

If you've got three or four clear nights forecast and then there's something worse coming in like a front, then watch the stars for three or four nights and try and pick the moment when you notice the amount of twinkling change.

That is one of nature's earliest warning signs of weather change.

Again, our ancestors would have been all over this because they didn't have the opportunity to cheat.

But what's happening is moisture in the upper atmosphere, when that starts going up, that's one of the earliest signs that change is on its way.

So as the starlight hits our atmosphere, the more moisture, the more twinkling.

So we just put those simple pieces to go together and we get more twinkling in the stars.

Ah, there could be some bad weather on the way.

Exactly.

So in space, stars don't twinkle.

So you can look across a million miles of space and you won't see the stars twinkling.

Not many of us will get that opportunity, but that's theoretically true.

But from the surface of planet Earth, we're of course looking through our atmosphere.

And even dry atmosphere, i.e.

not much weather out there, there will be some twinkling because there's little particles that the light is bouncing off.