CLOUDS form by condensation or freezing of water vapour, and the way they form very much depend upon the climatic condition that prevails at any one time. Anticyclones produce small delicate cloud formation and they rarely give any precipitation. Small fair weather cumulus enhance the skies, around its flank rolls or bands of stratocumulus form. In depressions low nimbostratus or cumulonimbus cloud often form, especially along the weather fronts. Shower cumulus cloud forms within the clear brighter skies behind cold fronts giving showers in the unstable air. Various hues take place in certain conditions, when the air is dry with plenty of dust, the reds and orange hues prevail. When the air is full of moisture the blue sky can take on a greenish hue and before stormy conditions, the clouds often take on a purple tinge.

The best hues occur when the rising or setting sun reflects upon and through high cirrus, cirrocumulus and medium level altocumulus cloud formation. It reaches its peak a few minutes after the disc of the sun has dropped beyond the western horizon, or a few minutes before the sun rises above the eastern skyline.

A trained observer can predict the weather several days in advance without seeing a forecast, by the type of cloud and colouration. The sky to a meteorologist is like the blood stream to a doctor, it shows the state of play weatherwise, or in the case of a doctor, the blood stream shows the illness or condition of a patient.

Next Week: The Autumn Scene.

Glossary:

Condensation: The change from gas to liquid.

Weather for coming week Monday 19th October-Friday 23rd October

The high pressure has moved away with a deep depression taking residence to the west/north-west of the UK, bringing an autumnal interlude this week.

Monday set fair with light winds. Tuesday into Wednesday a wet windy spell will take over.

Thursday and Friday brings sunshine and local blustery showers.

Windy throughout with gusts to 45 mph expected on Tuesday and Wednesday.

Mild frost free nights due to winds coming in from off the Atlantic.

Maximum temperature 11-14c 52-57f.

Minimum temperature 10-13c 50-55f.

Last Week's Observations (Monday-Sunday)

Highest day temperature...........18.2c on Wednesday 14th October

Lowest night temperature...........0.6c on Monday 12th October

Wettest day..............................4.4 mm on Thursday 15th October