Entries tagged "clouds"
2011-12-22
Happy Winter Solstice One and All!
Here's an interesting solstice fact for you: the Earth is actually receiving more solar radiation at this time of year than at any other time. This is because the Earth does not orbit the sun in a circle, but in an ellipse. In the northern hemisphere winter the Earth is at its closest to the sun, a point called 'perihelion', but in summer it is at its furthest point, or 'aphelion'.
The Guardian have published a little article on the timing of the winter solstice.
However, my favourite solstice…
2011-08-10
I took this picture a few minutes ago. For those of you interested in these sorts of cloudscapes then here is a good tip for finding them:
Take a really keen interest in the sky whenever bad weather is forecast after a good spell. Don't wait for the change to become obvious though, the interesting higher clouds: the wispy cirrus, mares' tails, mackerel skies etc. will all be found just before most people notice that the weather is changing, so you need to remain aware.
It works the other way round too of course, if you don't…
2011-01-20
Sometimes I feel like a big game hunter. Not a very good one though, as the idea of shooting the last white rhino, or whatever poor soul is struggling to cling onto their mortal coil, fills me with as much horror as you might hope.What I mean is that I often find myself creeping about rather stealthily, for fear of disturbing the animals (sometimes these animals are the kids who I dare not wake up too early for fear, in the words of Russell Crowe in Gladiator, of 'unleashing hell').I move out and forward, toes on grass, silently caressing my…
2010-12-17
Just saw and managed to snap a beautiful 22 degree moon halo. They are caused by the moon's light refracting through the ice crystals in the high clouds. In this case almost certainly thin cirrus clouds which are presaging the arrival of bad weather. Halos are not the same as moonbows, although they are often called that in error.
Will write more about them tomorrow if I get the chance, but wanted to get the photo up while I could.
2010-12-10
Venus and the brighter stars, like Arcturus, appeared shrouded in a veil this morning.
This was not mist close to the ground - horizontal visibility was excellent - but thin layers of high cirrus clouds. This effect has been used by navigators and travellers the world over as a sign that the a front may be approaching and a weather change is likely.
Cirrus on its own is not a guarantee of anything, but when followed, as it so often is, by cirrostratus and altostratus it is a strong indicator of an approaching warm front.
In…
2010-11-25
Last night the conditions felt right for a walk in the woods. There were plenty of clouds, but large gaps suggested that the stars would not hide for long periods. The moon would not be getting up until later and the breeze was too light to be of help. I needed the stars.
I set off as the last light from the sun faded in the southwest. Cassiopeia and Cygnus neatly sketched out north for me, even when Polaris was well hidden. When moving south I used Jupiter and Aquila.
Four hours later I returned, having spent…
2010-10-16
Nearly all navigation is an attempt to join landmarks together. Even those on boats crossing oceans are probably hoping to find a landmark they recognise as the final part of their journey.
The word, 'landmark', simply means something that makes a location recognisable. It is deliberately vague as it can apply to anything, a landmark may be extraordinary - the statue of Christ the Redeemer towering over Rio de Janeiro's from Corcovado mountain. Or it may be mundane - a red postbox at the edge of a village.
The more confident you can be that you have…
2010-10-08
These two photographs were taken this morning, within a few seconds of each other and from exactly the same spot. In the book I touch on the difference between viewing mist horizontally and vertically and these pictures illustrate the point nicely.
Mist and fog, which is just a word for intense mist, are low visibility caused by looking through millions of suspended water particles. When we look horizontally we have to look through hundreds of metres of these particles and the effect is very poor…
2010-10-07
I was just 'tweeted' by Anne who had spotted what initially appeared to be an unusual light phenomenon appearing in some cirrus clouds. I think it is just a small arc of a standard 'primary rainbow', but part of me desperately wanted it to be a 'fire rainbow' which I have never knowingly seen.
Fire rainbows (see photo) are very rare and form in cirrus ice crystals at high altitudes; their coloured arcs are near horizontal and parallel to the horizon. Fire rainbows can only come into being if the sun and atmospheric conditions meet…
2010-10-04
On Friday I enjoyed a warming cup of hot chocolate with adventurer and ocean rower extraordinaire, Sarah Outen. We arranged to meet in Brighton and I had hoped to saunter between the boutiques and purveyors of rare tat, before pulling up a chair in a bohemian cafe near the sea. Instead I sprinted twenty yards from the train station, felt the cold heavy rain run down my neck and then ducked into a disappointingly ordinary peddler of hot drinks.
Fortunately I got a chance to escape all that by listening to Sarah's memories of rowing, alone, across…
2010-09-29
A weekend of sailing has just passed, one that was full of meteorological kindness.
Nature was generous in two ways over the weekend - perhaps as a reward for my having set up a page of weather lore?
Firstly, blue skies, fair winds and warm sun ruled over the Solent. Secondly, an approaching warm front signalled its intent, in line with meteorological science and common folklore, by sending a team of mares' tails ahead. These cirrus clouds would be followed by cirrostratus, altostratus and then the rain-bearing nimbostratus. A show was being promised, and then put…
2010-09-10
The past few days have seen me bouncing between meetings in London - pinging between Kensington, White City and Theatreland. Throw in a Tube strike on the Tuesday and the stage was set for some urban natural navigation.The sun, trees, churches, clouds and satellite dishes all played their parts, but there are so many lesser known roles in the epic production that is 'City Navigating'.As if to prove this I received a message a couple of days ago from someone who had read the book and got in touch with some intriguing urban ideas. Clem McEwen drew my attention to…
2010-08-04
I returned from a family trip to Brittany yesterday and what better welcome back than to come downstairs this morning to find Jupiter beaming at me through a skylight. It is a firm fixture in the early morning sky now and consequently is being confused by many for Venus. If a bright white object is visible when it is too light to see many stars then you are likely looking at Jupiter or Venus, and if the sun is more than fifty degrees away (five extended fist-widths) then that narrows it to Jupiter. This is an exercise you only need…
2010-04-06
For the past few evenings I have been heading out into the Downs to find a good spot to keep watch out to the west. A sunset is always worth a walk, but there is rarer game worth hunting for in the skies at the moment. Unfortunately the clouds came in at the last minute last night and obscured Venus and Mercury again.Such a shame, it would have been an unusually good opportunity to catch them going to bed together. Fear not, I have a near foolproof plan for spotting them and shall report back with my results. If, over…
2010-02-18
I landed back at Gatwick last night following an accidental visit to Tenerife.The wind has been my friend on so many occasions recently, a dependable breeze helping me on my way through the woods or the clouds scudding overhead pointing the way home. It was probably time that it reminded me that it is not just in the business of helping me on my walks.The plan was simple: I wanted to use a one week gap in the diary to get out to one of the wildest spots within five hours of home to do some natural navigation research. Days…
2010-02-02
I went for a walk in the South Downs yesterday afternoon. The air was cold, there were still chunks of ice lining the north-facing side of chalk ruts in the path. The sun was up for the first part of the walk and made direction-finding easy. When it fell below the hills to my southwest it gave different opportunities. One of my favourite dusk techniques is to use the light reflections of cloud edges to gauge where the sun must be behind higher ground. This photograph from 4.30pm yesterday shows this effect quite clearly. The sun is reaching the far…
2009-11-24
I went for a short walk in the dark last night. The clouds were firing past the moon and jupiter giving a very eery feel as the light levels rose and fell dramatically and the wind tore threw the branches. This rushed picture shows a blurred moon, seen through some branches. The moon and Jupiter were very close to each other last night, near conjunction and a blurred Jupiter can hopefully just be seen below it and to the left, also mired in cloud. One of the branches is close to touching it.
2009-11-23
We had some old friends staying this weekend and decided to laugh in the general direction of the forecasts and go for a walk in the woods. It was dry for half an hour, but then the clouds moving over our heads, and visible in the gaps between the near-bare trees, changed their scudding direction by almost ninety degrees. This was the starting gun for a predicted and yet sudden change in our weather fortunes. We turned at our halfway point, the 18th century Nore Folly perched at the edge of the woods and looking out over Slindon and…
