First thing this morning, when I woke up it was blowing a gale and absolutely chucking it down. I fell back asleep, and woke up just after the time I would normally be up. I hadn’t expected to get up or go out for a walk.
The second time I woke up, I felt a bit guilty that I was being lazy. I looked out the window and couldn’t tell whether or not it was raining. Well, I have a perfectly good raincoat, it didn’t look like it was raining heavily, so I thought I’d risk it, except because of the raincoat it wasn’t really a risk.
As it happens, it did rain a couple of times, but not too heavily, and not for too long so it was fine. There wasn’t much happening in the harbour, because I was running late, I got to the Waterfront just in time to see the Mon St Michel passing the spinnaker, from a distance that meant I couldn’t get a good picture.
The clouds were quite high, and there was a bit of a breeze blowing. There were a couple of breaks in the cloud. I had previously approximated the amount of cloud as a percentage of the sky covered, but a few years ago a close friend said no, it’s not %ages, it’s 8ths. As you do, tonight I just googled why 8th’s – the actual unit of cloud is an Okta (I get the derivation of the unit). The explanation, which as usual is more complicated than you would expect is copied of Quora in an answer given by a gentleman called Robert Johnston. https://www.quora.com/Why-is-cloud-cover-measured-in-oktavs/answer/Eric-Burns-22?ch=99&share=0de59aee&srid=uYORF
Cloud cover on the visible sky, also known as ‘the celestial dome’ is measured in octas: That is in eighths. If the whole sky is overcast with one type of cloud it would be eight eighths cloud cover. But each of any different type of cloud is estimated in the same way so an observation might record 3 octas cu, at 1000 ft 4 octas sc at 2000, 5 alto cu @ 5000 and so on : The total can be more than 8 or less on a fine day when there is more blue sky. The reason cover is measured in eights is because it is easily divisible: Half cover would be 4, quarter 2 and an eighth 1 in any case the amount of cover can only be estimated approximate.
An earlier system divided the sky into ten ‘decas’,.This had two disadvantages: It attempted at over accuracy and also ten is only divisible once by two. Decas were clumsy.
The next thing I want to do, is when it is dark is get out and find Leo – I’ve never known how to find it, and I found an excellent YouTube channel that tells you exactly how to find it. I also found an excellent method of making my iPhone display red so that it doesn’t blow my night vision. Although, the light pollution here is so bad I don’t think it’ll makes any difference. All I need now is for to get dark and for there to 0 Okta of cloud! https://www.google.co.uk/search?q=how+to+do+a+shortcut+to+make+my+iphone+screen+red+for+astronomy&client=safari&hl=en-gb&ei=zbHkYKr5H8GAi-gPzemcuA8&oq=how+to+do+a+shortcut+to+make+my+iphone+screen+red+for+astronomy&gs_lcp=Cgdnd3Mtd2l6EAM6BwgAEEcQsAM6BAghEApKBAhBGABQuIICWPjHAmDyzAJoBnACeACAAV6IAZAPkgECMjWYAQCgAQGqAQdnd3Mtd2l6yAEIwAEB&sclient=gws-wiz&ved=0ahUKEwjqk7nQmc_xAhVBwAIHHc00B_cQ4dUDCA0&uact=5
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