On Sat, 16 Jan 2016 23:15:12 -0000
"Bernard Burton" wrote:


"John Hall" wrote in message
...
I saw a rather fine sundog today, at about 11:50, here in Cranleigh.
It was to the left of the sun, by 22 degrees I should think. I
couldn't see one to the right of the sun, perhaps because there was
a patch of high cloud to the sun's left but the sky over and to the
right of the sun was mostly clear.
--
John Hall
"Honest criticism is hard to take,
particularly from a relative, a friend,
an acquaintance, or a stranger." Franklin P
Jones


Yes John, there were some very good optical phenomena today. I made
this note with my 1500 ob. It is many years since I saw a good
example of a 46 deg halo, albeit only partial.


Wokingham 16 January 2016
Exceptional halo display at 1150z, LH parhelion almost too
bright to look at directly, a short section of the parhelic circle,
about 30% of the 22 deg halo, white, a brilliant circumzenital
arc and about 20% of the 46 deg halo, meeting the CZ arc,
well coloured but less bright than the CZ arc. At times during
the following 45 minutes both the LH and RH parhelia came
and went, sometimes very bright, and also the CZ arc appeared
faintly. Also at different times, the LH and RH parhelia at 120 deg
were briefly to be seen. This whole display seemed to be in fall
streak cirrus at or below the Ac clouds present at around 5 km
altitude.


Damned annoyed at having missed that!

I see from the radar that the base of the cirrus would have been at
about 2.5km (about 8,000ft) which just scrapes into the medium-level
cloud level. A halo I saw one November a few years ago was in cirrus
whose base was 6,000ft, officially low cloud. When I was an observer,
I think I'd've got a rocket for reporting cirrus at 6,000ft. ;-)

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
http://www.scarlet-jade.com/
I wear the cheese. It does not wear me.
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