Entries tagged "cirrus"
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…
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.
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…
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…
The northerly winds were carrying high cirrus and contrails down towards the coast this morning. They have brought colder air, as forecast yesterday. This gave us our first frost of the season. The feel and even the sounds of the grass underfoot have a relationship with the direction the air is moving.
I took this picture a week ago. It shows the lower fair-weather cumulus clouds against the upper cirrus clouds. It is not at all unusual to watch the lower clouds and upper clouds move in different directions and to feel a third wind direction on your face at the same time.
This morning's sun was a strong enough clue, but if we wanted to know which way was southeast then these aircraft contrails are pointing the way to the continent.It looks like a particularly busy morning for aircraft, but this is just a reflection of atmospheric conditions. The hydrogen-rich jet fuel has mixed with oxygen, reacted in the engines and formed, among lots of other lovely and not so lovely things, water. In certain temperatures and humidity levels this water freezes into ice crystals. The high cirrus clouds that we normally see are also composed entirely of ice.The length of time…
Tonight's early evening sky is a feast of cloud types. Cumulus, passing low and darkened by the shade, perhaps the last of the fair-weather clouds for a bit. Higher there is cirrus, cirrostratus and altostratus all heralding the approaching warm front. Thrown in for a bonus there are some contrails from aircraft heading to and from the continent.