I think these may be altocumulus –
Altocumulus are medium-height cumulus clouds (between 2000 - 6000
metres above the ground) . They are a sign that unsettled weather is
on the way.
||On a bright
Winter's day over Epsom Downs, contrails form a noughts and crosses board in the sky
gather over London on a warm spring day
||A small cumulus
cloud floats through a summer sky. Notice the grey colour of the under side of the cloud,
which is simply caused by shadow.
||A double rainbow in
the Swiss Alps.