Martin Rowley wrote:
"Ian Currie" wrote in message
k...
Actually in Surrey the sky was not that clear with high level cirrus
giving
a rather milky look at times and the light almost looked like that
experienced during partial eclipses of the sun. During the evening
there
were some excellent mock suns visible and a faint circumzenithal arc.

Ian Currie-Coulsdon

... yes Ian, yesterday was one of those days which lead you to mistrust
statistics relating to Cirrus amounts from past years; it was only early
and late (lower solar elevation) that you could see that there had been
a lot of very fine, thin Cirrus around for much of the day (at least
here in east Berkshire) - if it doesn't show much character when the sun
is high in the sky, this cloud is very difficult to assess.

Martin.

Did anyone else have a plague of contrails around midday yesterday? The
first couple appeared around 10am here in Shrewsbury, then they were
joined by more that spread out to cover half the sky with what looked
like Ci/Cc/Cs. Didn't stop the sun beating down, but not till about 3pm
did they dissipate (burnt off, or blown somewhere else?). By contrast I
can't see any so far today.

I find a good way to detect thin cirrus is to wait till it is dark, and
then see what the faintest stars visible are.

Edmund