Stormy Weather II

[Serial_Apologist]

We on a hill, would I. Be expecting more frost?

Lovely morning, so far.

Well, (or should I begin "So"?), normally temperatures tend to fall with height, obviously; but in the case of valleys at night, they tend to be colder than their surrounding hill tops - one obvious reason being that the sun disappearing behind those hills earlier than atop them means temperatures have a longer time span, longer nights, in which to fall. There's another factor, known as "katabatic flow", in which air seeps down into valleys at night from surrounding hills, further aiding the cooling process. To be honest I don't know how this works, however, because descending air usually tends to warm up by compression, as we see with inversion caps preventing upward convective growth of cumulus under high pressure conditions.

[oddoneout]

Well, (or should I begin "So"?), normally temperatures tend to fall with height, obviously; but in the case of valleys at night, they tend to be colder than their surrounding hill tops - one obvious reason being that the sun disappearing behind those hills earlier than atop them means temperatures have a longer time span, longer nights, in which to fall. There's another factor, known as "katabatic flow", in which air seeps down into valleys at night from surrounding hills, further aiding the cooling process. To be honest I don't know how this works, however, because descending air usually tends to warm up by compression, as we see with inversion caps preventing upward convective growth of cumulus under high pressure conditions.

Britannica suggests that the speed of descending air is relevant https://www.britannica.com/science/katabatic-wind Certainly it is something which agriculture and horticulture has to be aware of - frost pockets are not good for fruit blossom etc.
Interesting bit here about implications for aviation https://www.skybrary.aero/index.php/Katabatic_Wind

[BBMmk2]

Another good day today, by the looks of it. Going to town later, to our local hospital for a regular blood test, then onto the worrying environment of Sainsbury’s!

[cloughie]

Looks a good day here today - hopefully will be warm enough to visit the pub which today reopens its (garden) door this afternoon.

[Pulcinella]

Not quite so bright today here as yesterday was, but still good enough to join a few neighbours (socially distanced, of course) for coffee (and probably a bun!) outdoors at the local library, since that has now become an option again.
I need to renew my library ticket too (as well as letting me use the library, it's the easiest way to get free access to the Minster, though other ID showing York residency works just as well), and I'm donating my copy of Mordew (sorry, DracoM; didn't like it at all, but I finished it, and as I'm a 'careful' reader it still looks brand new) for which I see they have a reservation waiting but no copy as yet!

[DracoM]

'Mordew'????????????
Sorry - don't understand?

[cloughie]

'Mordew'????????????
Sorry - don't understand?

Well better than ground frost!

[Pulcinella]

'Mordew'????????????
Sorry - don't understand?

I thought that it was a book that you had recommended, by Alex Pheby.
Perhaps someone else did; I'm sure I saw mention of it on a forum thread.

PS: Sorry, Draco.
It was first mentioned by Belgrove (post #2342) and then endorsed by Highland Dougie (post #2347 and post #2359) on the 'What are you reading now?' thread.

No blame attaches to you whatsoever!


It was you who recommended the Patrick Ness Chaos walking trilogy, which I DID enjoy!

[Serial_Apologist]

Well better than ground frost!

Which we had yet again, this morning. Otherwise it's a nicer day than yesterday, with the cumulus not this time piling up into shower clouds, so the inversion cap must have descended. It will probably frost up again tonight, meaning I will have to don gloves for my 9 am cycle ride to the nearest Sainsbury's. It's a good time for the weekend's grocery shopping: unlike where I was living before, in Essex, where the car park would be full by 9 am, most people around here have presumably been partying the previous night and are still sleeping it off!

It all still looks good for the weekend, and gradually warming up for "proper" spring temperatures next week.

[DracoM]

It was you who recommended the Patrick Ness Chaos walking trilogy, which I DID enjoy![/QUOTE]

HURRAY!

And fantastic Spring day here - warm, inviting, Vitamin D rich!

[cloughie]

Which we had yet again, this morning. Otherwise it's a nicer day than yesterday, with the cumulus not this time piling up into shower clouds, so the inversion cap must have descended. It will probably frost up again tonight, meaning I will have to don gloves for my 9 am cycle ride to the nearest Sainsbury's. It's a good time for the weekend's grocery shopping: unlike where I was living before, in Essex, where the car park would be full by 9 am, most people around here have presumably been partying the previous night and are still sleeping it off!

It all still looks good for the weekend, and gradually warming up for "proper" spring temperatures next week.

Good to see you picking up the Cornish way of speaking!

[BBMmk2]

A lovely day today. Just a nip, this morning but probably going to be warmer.

[Pulcinella]

A lovely day today. Just a nip, this morning but probably going to be warmer.

Isn't it a bit early to be starting on the whisk(e)y, BBM?
Or was it from the dog, asking to be let out?

[cloughie]

Isn't it a bit early to be starting on the whisk(e)y, BBM?
Or was it from the dog, asking to be let out?

Or the hair of the dog?

Another beautiful morning here 10C.

[DracoM]

Another spiffing Spring day.