Unstable

Cold dry air that overlays warm damp air leads to unstable cloud behaviour. Cumulus clouds develop and rise into the colder air, and latent heat is released as water vapour condenses. The resulting updraught lifts more damp air and the characteristic white cauliflower shape bursts upwards until it can get no higher and an anvil shape starts to form.





So little light penetrates these huge clouds that it turns quite dark underneath, a sign that all is not well overhead.

These conditions create vast amounts of condensed water in the form of droplets or ice high in the cloud. This in turn gives rise to sudden downpours and even thunderstorms.

The uplift in these towering clouds is balanced by descending cold dry air, giving the patches of blue sky. This produced the characteristic "sunshine and showers" cold front forecast.




I hope your clothes and camera are showerproof...


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