[Halo]

Please post any alerts and reports of atmospheric optical phenomena in this thread.

[Halo]

Coronae were observed on both the nights of 1 and 2 January, surrounding a bright aureole around the moon. A veil of cirrostratus, associated with a warm front, was responsible for a very weak 22 degree halo around the moon from 1945Z 2 January, lasting for over two hours although there were breaks when the cloud grew too thick.

[Halo]

There was a faint purple light, extending to around the 20 degree mark noted at 1630Z 3 January.

[Halo]

A very weak 22 degree halo (upper portion only) was observed between 1030Z-1045Z 4 January seen in thick cirrostratus associated with a warm front. Rain followed after around 3 hours.

Aureole was observed in three different layers of cloud during the evening of 5 January and varied in shape dramatically due to the fast-moving nature of the clouds. There was a small diameter, less than 1/2 degree in radius, perhaps caused by high cirrus cloud or haze, not sure. There was no coronae observed.

[Halo]

High cloud associated with a warm front caused a weak 22 degree halo (upper portion only) around the moon on the evening of 8th January (1905Z-1920Z).

[Halo]

A faint corona was observed around the moon, in particular, between 2030Z-2100Z, surrounding a fairly large aureole. Earlier, there was also iridescence as well in a high-based stratocumulus layer caused by the moon and, maybe a hint of a short pillar.

Not really atmospheric but I noticed some quite vivid heilgenschein in the light of the moon. Not seen this aspect of the heilgenschein (noticed frequently in sunlight) although it probably isn't all that rare.

Date of all the above 9th January 2012.

[Halo]

Some quite vivid banded iridescence was observed in a gap in the clouds at 0905 UT 12 January. There wasn't a great deal of time to observe the phenomena properly due to an encroaching cold front.

Cirrus was responsible for a colourful sunset which was commented on by quite a few members.

Images of the event taken by Howard Kirby and "Floss The Dog" can be seen below:

My link

My link

[Halo]

A very weak 22 degree halo was observed for half-an-hour (beginning 0930 UT) in thick cirrus on 13 January 2012. Also, a weak partial fogbow was seen at around 1045 UT.

A dome-shaped area of purple light was observed after sunset, beginning 1630 UT, peaking at 1645 UT and fading 15 minutes later. It extended to about half-way up the sky from above the horizon with bright yellow underneath that.

[Halo]

At dawn on Saturday 14 January a strong, unusual purple light was observed, beginning 0715 UT, peaking at 0745 UT, and ending by 0800 UT although there was still a fair glow for awhile after that. It began as a red, crimson band low over the horizon which gradually rose up. This banded area turned yellow whilst an area of haziness began to take on a purple hue. This turned brighter and there appeared streaks and striations within it. There was a yellowish counter-glow, not particularly strong, on the opposite side of the sky. I reckoned the purple light extended to around 50-60 degrees. After peaking the purple began to fade but interestly the area of sky below took on a very milky almost white appearance for a time. After the end of the purple stage, a pale-yellowish to whitish glow persisted for awhile and was gone by 0815 UT. The streaks, lines, wisps were observed within this too.

A much weaker purple light was observed after sunset but there were cloud streaks, wisps, undulations within this.

It seems that this spectacular dawn was likely caused by polar stratospheric clouds (of the 1st type). Nacreous clouds were widely observed in Sweden on 12-13 January.

http://www.atoptics.co.uk/fz728.htm

http://www.atoptics....ighsky/psc1.htm

The green flash was observed at sunrise.

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[Halo]

A green flash was observed at sunrise on 15 January 2012.

Iridescence was observed and photographed by Dave Hancox (Ayrshire). See below:

http://www.ukweatherworld.co.uk/forum/index.php?/topic/88910-iridescent-cloud-show-ayrshire-15012012/

[Halo]

Sporadic optical phenomena during the morning in thick cirrus associated with an upper occlusion on 17 January 2012. Most of it was concentrated between 1115Z-1145Z where the upper portion of a 22 degree halo and both parhelia were observed. A left parhelia was earlier occasionally observed.

[Howard Kirby]

I can just about see a UTA or something similar right now.

[Richie]

Observed a bright left hand side parhelia and a fainter tangent arc at 1853 UTC on May 8th. The arc faded after only a few minutes, but the sundog was visible for a good fifteen minutes or so before clouds encroched and blocked the view.

[Peter H]

The sun is out in places, there is some cirrus about - and this is the short period of time each year when a circumhorizontal arc can be seen. So, it's worth just keeping a check on the southern horizon - I think I saw some hints of colour this morning.

This post has been edited by Peter H: 19 June 2012 - 12:04

[Halo]

This thread hasn't be used for a long while, perhaps better get it filled up!

Contrails filled the whole sky by late morning with some optical phenomena observed, parhelia, 22 degree halo (incompleted), circumzenithal arc, upper tangent arc (brightest of all), and a parry arc. If skies are similar it might be an opportunity to see this quite rare halo (October 9 is the 3rd day for me) as it has been seen here for fairly long periods so far today. There are hints of a supralateral arc attached to the CZA. There are presently visible here atm.

A clue to what to look for:

http://www.atoptics....halo/parry1.htm

[Halo]

Quite a long-lived and vivid green flash was observed at sunset on 27 October 2012. I was surprised at the length of it but I reckoned it lasted around 20-30 seconds before the very last bead disappeared behind a distant Welsh mountain.

[Richie]

Partial rainbow observed around 0900Z.

[Halo]

Quite a bright halo on the 31 October during the morning period and this was sometimes capped by an equally as bright upper tangent arc though the former as the most persistent. The ring was seen off and on into the first part of the afternoon but always weakly. Rain associated with the cold front occurred roughly two hours after the end of the optics.

[Halo]

A quite bright 22 degree halo was observed during the morning of 1 November in thick cirrus with red the prominent colour. It was commonly seen with a much weaker circumzenithal arc. It continued in more limited sightings into the afternoon and fainter.

Only a couple of sightings of a left parhelion were recorded on the morning of 2 November.

A complete lunar halo was seen during the pre-dawn hours on 3 November.

[Halo]

A weak 22 degree halo (upper portion only) was observed during the late morning of 3 November for a time, perhaps a hint of upper tangent arc in thick cirrus associated with the rear of a trough that passed through. There were also pieces of halo and left 22 parhelion incorporated into the halo fragment during the afternoon as thick cirrus slowly increased from the west in connection with shower activity in that direction. No other halo types were seen on 3 November.