"Nick" wrote in message
...
Some sort of slow moving shower seems to be moving across from the
west currently but more significantly, the light levels have been
reduced to those typical for around quarter of an hour after sunset.
Can recall few such noticeable "day darkness" events as this.

Nick

Just spotted this thread. I agree with your day darkness
assessment. It was quite widespread, covering parts of
southeast Wiltshire (near Amesbury) and I encountered
further particularly dark skies driving back home.

Low patches of stratus about 200ft off the ground were
coiling upwards into the embedded Cb. In cahoots with
with the thick Nimbostratus, I believe this is the cause of
the very dark conditions, December light notwithstanding.

Nigel