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Hi again Jarmo, Les, Michael and halo enthusiasts
Please find below the halo and phenomenon list for May and June 2002.
Sorry about the delay for the May list. These lists are a bit more
detailed. I hope to improve them as I go along by adding pictures etc.
Best Regards
Kevin
May 2002
1st: A rainbow was observed at 1645 UT during a shower. Two supernumary
bows were embedded in the primary.
2nd: A fragment of 22 degree halo (top) was seen around 0600 UT.
An upper tangent arc was seen between 1100-1130 UT with red and blue. A
faint circumzenithal arc was seen during the early evening around 1700 UT.
High cloud had been scattered during the day in a very slack pressure
gradient.
3rd/4th: A ridge of high pressure covered the country and aside from high
cloud associated with shower activity on the 3rd there were no phenomenon.
5th: Parts of the 22 degree halo was seen intermittently (1430 UT)during
the afternoon and again during the evening. The evening apparition was
accompanied by mock suns with red colourings. These were mainly caused by
ex-contrails mixed in with cirrus.
During the evening, altocumulus lenticular and related wave-clouds were
prominent, and iridescent colours were seen in some of these, mostly
purple/green. Ridge of high pressure still covers the UK although a
frontal system associated with a depression over the Low Countries pushed
high cloud and wave-clouds across our area.
6th/7th/8th: All overcast days with occasional sun due to the remnants of
a slow-moving front.
9th: A bright upper tangent arc appeared during the morning from 0915 UT
and persisted for over an hour. Colours were faint. During this time, a
faint right sundog (some colour) briefly appeared. Shallow areas of
low-pressure surrounded the UK and there was a extensive covering of high
cloud limited at times by lower cloud.
10th: Mainly overcast, sunny later but no high cloud.
11th: A bright to very bright upper section of the 22 degree halo was
observed for much of the morning and into the afternoon. Colours were very
obvious, red the most prominent with yellow and blue also seen. During the
morning, the halo was accompanied by bright left&right parhelia but
colours were pale. Both had long spikes. Portions of the parhelic circle
were seen during the morning. It joined the sun to both mock suns inside
the halo. There was an extension from right hand mock sun, of the parhelic
circle, of up to 40 degrees. The circle was faint but obvious enough. A
faint and brief circumzenithal arc was seen during the display. This
interesting halo display was caused mainly by artificial ice crystals from
aircraft engines. In fact, the halo display at one point was cut into
three segments by contrail shadows. The morning had started with scattered
cirrus but more and more appeared as air pollution increased.
12th: Although there were cirrus cloud during the day ahead of a frontal
system there was no phenomenon.
13th: Cloudy and wet.
14th: A very faint, partial rainbow was seen at 1530 UT during light
showers. It was very low close to the horizon and it was a struggle to see
it.
15th: A faint segmented 22 degree halo was seen between 1645-1700 UT and
between 1800-1900 UT (with colourful sundogs and vague circumzenithal arc)
ahead of a developing warm southerly airflow.
16th: Portions of the 22 degree halo was seen from time to time, sometimes
with colour. A right sundog was seen with some colour. A series of weak
circumzenithal arcs were caused by ex-exhaust trails ( four in total ).
Faint iridescent colouring was seen in lenticular clouds. Extensive
high-cloud behind warm front over Scotland.
17th: A weak 22 degree halo was visible during much of the morning and for
a time in the afternoon. Some red colour was seen. This phenomena occurred
ahead of a frontal trough pushing up from the southwest.
18th: Part of a 22 degree halo was seen in the evening, only red was
observed. The phenomenon was brief and short-lived occurring after an
occluded front had passed.
19th: A 22 degree halo was seen for much of the morning with colour (red
mainly). It became much fainter in time as thicker altostratus spread in
association with a northeastward moving frontal system.
20th: A complete and bright 22 degree halo was observed between 1500-1530
UT. Colouring was seen. The halo appeared after a sudden break of low
level stratocumulus/cumulus clouds. A cold front crossed during the night
of the 20th and 21st.
21st: A bright and complete 22 degree halo was observed for an hour
between 1000-1100 UT with red seen. The halo became fainter as cloud
lowered and thickened ahead of a frontal system associated with a deep
depression approaching Ireland. Earlier in the day, a weak and disjointed
V-shaped upper tangent arc appeared briefly above a shower-cloud (0600
UT)in a scrap of high-cloud.
22nd: A bright and red top section of a 22 degree halo and weak sundogs
appeared between 1630-1645 UT in a cumulonimbus anvil plume.
Later in the evening, anti-crepuscular rays were seen against
stratocumulus/cumulus clouds in the distance. During this time,
crepuscular rays diverging from the sun were bright white.
23rd: A weak left sundog was seen at 1830 UT with faint red. High clouds
because of shower-cloud activity. Shortly after, a segment of a rainbow
was seen in a distant shower.
24th: A bright rainbow, with partial secondary and two supernumary bows (
unsure about a third) occurred following a shower around 1600 UT. Later
parts of a rainbow was seen embedded in a cumulonimbus cloud between
1815-1830 UT.
25th: Half of a rainbow seen ahead of a passing shower at 0550 UT.
26th: A faint circumzenithal arc seen at 1750 UT and left&right parhelia
(bright with colour) between 1845-1915 UT. These occurred in high cloud
behind a frontal system.
27th: Part of a rainbow was seen during the evening between 1815-1845 UT.
28th: Left sundog with colour was seen between 0515-0545 UT. Observations
limited to lower mid-level and low-level clouds. This mock sun occurred
ahead of a frontal system which brought rain for much of the day and
cleared during late-afternoon and early evening.
A bright and spectacular double rainbow occurred during a shower with
three supernumaries between 1850-1900 UT.
29th: Faint and brief upper tangent arc with red seen at 1400 UT.
Low-pressure covers Scotland and there were patches of cirrus with
showers.
30th:No optics today despite scattered cirrus. Pressure is building after
morning shower troughs.
31st: There were some nice iridescent colours in altocumulus, and on the
edges of cumulus with all colours of the rainbow seen in the latter, at
various times of the day. High pressure now dominated the weather but
patches of mare-tailed cirrus did cause a section of a faint halo (or
upper tangent arc?) around 1300 UT and ex-contrails caused a faint sundog
and circumzenithal arc during the evening.
June 2002
1st: A series of faint sundogs and circumzenithal arcs appeared during the
evening. This was caused by air pollution increasing the amount of cirrus
during that time. Only the red colour were seen in mock suns.
2nd: Sections of a 22 degree halo was observed during the first part of
the morning. The top was the brightest with red, yellow and blue colouring
around 0900 UT. However, altocumulus floccus clouds tended to limit
viewing of this. There was a large amount of high cirrus cloud ahead of a
cold frontal trough and this triggered thunderstorms later in the day.
3rd: A bright left sundog was observed between 1850-1900 UT. Red and some
yellow colouring were seen. This occurred behind a frontal system that
crossed during the day bringing a fair bit of rain.
5th: A faint 22 degree halo was observed during the first part of the
morning ahead of frontal cloud.
A lengthy gap here. Simply weather not favourable for halos etc.
12th: Faint top section of 22 degree halo and faint circumzenithal arc in
contrail in the morning. Occurred in scattered cirrus mainly as mentioned
ex-contrails.
Another gap.
16th: A bright complete 22 degree halo was visible between 0830-0900 UT.
The halo was seen at other times but faint and incomplete. A lot of high
cloud associated with a northeastward moving warm front.
17th: A solar corona was observed at various times of the day, as was
iridescence on clud edges. The phenomena was caused by the mid-level
remains of a cold front.
18th: A small top section of a 22 degree halo appeared briefly around 0800
UT. Caused by cirrus cloud associated with the rear of yesterday's cold
front remnants.
19th: A faint right-hand parhelia was seen at 0530 UT, along with sections
of a 22 degree halo. Scattered high cirrus cloud in the morning in an
otherwise cloudy day.
22nd: A left-hand sundog was seen (with colour) intermittently between
0645-0700 UT. Also seen, was iridescent in altocumulus cloud. Early
sightings during a cloudy day.
24th: A temporary increase of cirrus clouds caused both mock suns, and
various segments of 22 degree halo, between 0800-0900 UT. A ridge of high
pressure causing fine weather albeit cloudy at times. Full moon rose a red
colour and was oval shape due to extra refraction. Its position on the
ecliptic and its shallow angle to the horizon prolonged the apparition.
Skies were hazy during the evening.
25th: Mostly cloudy due to a decaying frontal system. Clearing late
afternoon. A weak right-hand sundog was seen during the evening with
colours. Cirrus that caused the parhelia derived from air pollution. The
moon again rose red and oval in shape.
26th: Increasing high cirrus cloud caused a variety of phenomena during
the morning. Both left/right sundogs with colour were seen from time to
time, parts of the 22 degree halo were also seen, the brightest part was
the top. A dishevelled and faint circumzenithal arc was briefly seen. All
this halo activity occurred well ahead of a developing cool northwest
airflow behind a cold front. This crossed later bringing with it heavy
rain.
28th: Between 1000-1130 UT, high-level altocumulus caused bright
iridescent colouring (mainly purple and green) and a corona around the
sun. The corona was also quite bright and at one point was accompanied by
a partial second ring. The corona merged with the iridescence at tijmes.
Shortly after, when the altocumulus cleared a bright and complete 22
degree halo appeared for half an hour. Fragments of the halo were seen
from time to time later on. A lot of high and mid-level cloud (and air
contrails) to the west of an area of low pressure.
29th: There was a bright 22 degree halo from 1300-1400 UT. Red was seen in
the inside. High cloud increased as the edge of a warm front
clipped us moving east to east-southeast.
30th: There was a bright 22 degree halo during the first part of the
morning with a right sundog. Colour was seen in both halo and sundog.
Cloud increased during the morning in response to a frontal system
approaching from the west.
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