revtothelimit - motorbike forum

Ok Ok, I know, that's sounds stupid - long day and can't work out how else to phrase it!! LOL

Anyway - down in Aime (about 500m altitude maybe) it was 1 degree and raining this evening.

Got to about 1500m and it was still 1 degree and very wet sleet

1800m - still 1 degree and wet snow

2000m - still 1 degree and dry light snow

How does that work??


I should probably know, but I don't!!

Might be because I'm tired, but I can't get my head around the same temps but the water is less solid lower day!! I've known it snow up here at 2000m when it's warmer than 1 degree. And very very much colder. It's also rained up here at zero degrees

So what gives?

And how does mother nature roll all them flakes flat???

You were at 1500 m, but the snow fell from higher up, where it was colder.

Could be wrong but snow isn’t rain that has frozen. The snow forms in the cloud itself (as the water vapour in the cloud starts to feeeze).

Felix wrote: Sat Jan 04, 2025 7:37 pm And how does mother nature roll all them flakes flat???

She's got loads of very fancy "cutters", like for pastry, but more fancy HTH

JackyJoll wrote: Sat Jan 04, 2025 7:41 pm You were at 1500 m, but the snow fell from higher up, where it was colder.

But the temperature was the same at 1500m as it was at 2000m

wheelnut wrote: Sat Jan 04, 2025 7:50 pm Could be wrong but snow isn’t rain that has frozen. The snow forms in the cloud itself (as the water vapour in the cloud starts to feeeze).

I didn't know that!!

But it's still weird that at the same temperature but different altitudes the consistency of the "snow" changes - well, weird to me

If its turning into rain at lower levels would that not be due to the flake defrosting as its been fluttering down longer than the ones landing up the big hill. <<< cant spell mountain

Remember your O level Physics.

Frozen water (snow flakes) need a temperature above 0 degrees to start thawing. They also need TIME, they have to absorb (IIRC) 80 calories per gram to turn to water at the same temperature. So at high altitude they can still be snow, a bit lower down when they have had more time they can be sleet, and lower down still they can be rain. All at the same air teperature (above freezing), and still without actually increasing the temperature of the actual snow/sleet/rain.

Doesn't answer the Q directly, but fascinating video if you're fascinated by this sort of thing.

Sometimes when it rains here, it evaporates before it reaches the ground so it stays dry

How do you know it is raining?

Cousin Jack wrote: Mon Mar 17, 2025 10:23 pm How do you know it is raining?

She looked down the hill?

Cousin Jack wrote: Mon Mar 17, 2025 10:23 pm How do you know it is raining?

We can see it falling higher up in the air. It's called Virga

Noggin wrote: Mon Mar 17, 2025 2:51 pm But the temperature was the same at 1500m as it was at 2000m

But it fell from the sky which is higher than the piece of land at 2000m above sea level.

What's snow ?

'It was one of those March days when the sun shines hot and the wind blows cold: when it is summer in the light, and winter in the shade.'

Cousin Jack wrote: Mon Mar 17, 2025 5:11 pm Remember your O level Physics.

Frozen water (snow flakes) need a temperature above 0 degrees to start thawing. They also need TIME, they have to absorb (IIRC) 80 calories per gram to turn to water at the same temperature. So at high altitude they can still be snow, a bit lower down when they have had more time they can be sleet, and lower down still they can be rain. All at the same air teperature (above freezing), and still without actually increasing the temperature of the actual snow/sleet/rain.

Nope, not at all! It was one of the few I passed, but have no memory of learning anything about snow!!!


Saw this online today. The massive snow storm that caused so much damage (mostly to trees) last week was a massive surprise in that the snow fell way further down the mountain than expecdted.

This helps explain that bit - especially as this time it was definitely warmer lower down!! A bit as CJ says, I think, but with added comment about wind helping the defrosting!!