Unfortunately in our part of mid-Devon we are surrounded by hills, and for most of the year are deprived of watching the ‘true’ sunset or sunrise, but in Winter we are a little less restricted both towards the southeast and southwest, as it was this evening. It looks like we might be in for an early frost if the cloud doesn’t roll in later during the night.
I’ve mentioned in several of the postings I’ve made this morning about how yellowish the clouds have been ever since dawn here in Devon. Well my neighbour has just knocked at the door to say just how reddish the sun was as he drove back from Cullompton just now. So I broke off from blogging and managed to capture a couple of pictures of it as it was just starting to poke through the thinning sheet of CS. I did pooh pooh the notion that it was Saharan dust that was causing it, but now I’m not so sure. I apparently missed the sun when it was at its reddest which is always the way of it!
Apparently the red colour of the sun this morning in Devon is partly the result of Saharan dust, and may explain the warm air over western Iberia yesterday.
Medium layer cloud is still much in evidence across the southwest this morning, possibly the remnants of yesterdays weakening cold front that marks the boundary between air with dew points of 9°C in Devon to 17°C in the north of France (fig 1). There is some rather fine altocumulus (fig 2), and despite the surface flow being east of north, I reckon the flow at 17,000 feet (LCBR at Exeter airport at 09 UTC) is from around 248° at 27 knots, if my rather crude estimates are anything to go by.
Or in this case, mighty cumulonimbus from little cumulus. It would have been interesting to see a time lapse of how this CB exploded into life in the middle of the English Channel this morning from somewhere high up on the south downs (fig 1).
There was some lovely fine AC castellanus towards the SE horizon in south Devon this morning (fig 2).
The first wave of thundery activity seems may have slipped further south than the Met Office chief forecaster anticipated (fig 3). But you never can tell with thunderstorms, as you can see with the speed that the one in the Channel developed, and I can already see some bright echoes on the weather radar across Suffolk at 09 UTC. This seems to be from the same arc of castellanus that’s spread ENE from across Dorset (fig 4), and looks to be all medium level instability, rather than the area of CB’s that’s now over the eastern Channel and NE France.
Funny, it already seems a long time ago now…
At first I thought that this was low AC when I first saw it, which shows you what a poor observer of cloud I was in my day, but the LCBR at Exeter airport reckons the base is 5,000 feet, and I’m not going to argue with that. Feel free to tag on some extra supplementary varieties to the description such as undulatus, perlucidus (gaps between), or stratiformis.
Here are some of my recent cloud images, it’s been a bit quiet as far as my photography goes this year, we seem to have missed out on any good sunsets. Last night was an exception though, not a colourful sunset but rather a broody dark display of SC with embedded mammatus, the base of the SC sheet was at around 5,000 feet according to the LCBR at Exeter airport.
It all ties in with the cloud in the visible satellite image of the same time that’s aligned ENE-WSW across southern England (fig 1). The 18 UTC analysis has a corresponding trough following behind the warm front on the analysis (fig 2), the bottom bit of the warm front is marked frontolysis by the Met Office no doubt because there is no cloud on it west of 1° east. There were some showery outbreaks of rain along the trough yesterday evening, so there must have been some instability associated with it as it moved SSE ‘ward (fig 3).
I noticed this very interesting photograph of a solar halo in cirrostratus with a condensation trail running through it on the Astronomy Picture of the Day website.
Suddenly people are reading that a new type of cloud asperitas has arrived on the scene, I even wrote a bit about it this week. Some people have now also started to think (if this article in the Guardian is anything to go by) that global warming has now produced many more exotic cloud types that have never been classified. I suppose as a cloud lover this should be good news to me, it’s making people more aware of clouds, in fact it’s popularising clouds, but to an old curmudgeon like me that’s not good news. It seems that popularising things that were once ‘nerdy’ or ‘geeky’ things to do just seems to have followed me through life. Here are a few of the things that I liked doing have now become ‘popular’ things to do:
- Observing and photographing clouds and cloudscapes since I first got an Kodak Instamatic in 1970.
- Programming – I wrote my first program, tic-tac-toe, in 1975 on the Sheffield Polytechnic main frame.
- Long distance walking – We attempted, but never finished the Pennine way in 1978 for our honeymoon!
- Computers – I started with a BBC model B in 1983 and it’s been downhill from there.
- Hi Fi – We bought separate Akai amplifier, tuner and tape deck in 1985, along with Wharfedale speakers and Pioneer record deck.
- Mountain Biking – We got our first ‘Muddy Foxes’ in 1987 and turned a few heads in Forres where we then lived.
- Munroing – I bagged 130 Munros between 1990 and 1995.
- Climate, but more especially climate change we now have so many experts.
You will probably think this is a remarkably churlish attitude to take, which I can’t deny, but there seems few pastimes or hobbies left to me these days that haven’t been ‘popularised’, and I haven’t even mentioned the programs on TV that have done their bit to ‘popularise’ DIY, gardening, cooking, sewing, baking, pottery, decorating, painting, travel, design etc. I think that I still have one or two passions that haven’t been popularised to any great extent (and I won’t even mention them just in case someone’s listening), but I’m sure that given time it won’t be long before they are also assimilated into the collective. I suppose with the speed of innovation these days, and the fact that there are now 7,493,150,887 of us on the planet (as of 0937 UTC on the 25th of March 2017), some of them with more leisure time than is good for them, popularising of our pastimes is just an inevitability.
I have a number of very decent digital SLR cameras, and the latest a Canon 6D takes what’s best described as very dramatic cloud images, which I love. But if you check the result immediately with reality, you will quickly see the image is not a faithful reproduction, the chip in the camera has sharpened and enhanced the colours, making the image much more dramatic than it really is. If I take the same image with my older Canon camera, a 5D, the image is very close to reality, and in truth a little bit boring. I like dramatic and of course use images from the 6D rather than the 5D because I know they will prove more ‘popular’ to my audience. It’s my belief that the rise in popularity in cloud photography, and the arrival of this new cloud type asperitas, coincides with the massive increase in mega pixel cameras (and their processing chip) that are built into today’s smartphones.
Just in case you were wondering, the top image (fig 1) which may resemble asperitas isn’t, and the reason I say that so confidently, is that here in Mid-Devon we are lucky to find ourselves less than 15 kilometers from two automatic weather stations both equipped with laser cloud base recorders, which report hourly SYNOP observations. As a retired weather observer this cloud almost fooled me, but I knew from observations at Exeter airport and Dunkeswell, that I was looking at a main layer with a base between 3,800 and 4,500 feet. This cloud was in fact stratocumulus and not asperitas, even with it’s undulating wave-like appearance. I’m just using this as an example that cloud sometimes, and more often than you would think, can fool us. I am not saying that asperitas doesn’t exist, it most obviously does, and I may have caught a couple of examples with my digital camera (6D) of it over the years (fig 2 & 3). The evidence across the southwest on that day from the observations, is that there was a good deal of medium level cloud with a base between 9 and 12 thousand feet.