A very pleasant day with a number of interesting aspects. Almost
cloudless by 1200Z and the sky a very deep blue. Some lenticular
cloud was observed and the illumination of this varied in a striking
manner from being an intense dazzling white about 30° from the sun (at
the same altitude) to being a dull grey at about 90° from the sun.
All this cloud disappeared by 18Z to be replaced by some high-level
Sc, max 3 oktas, which nevertheless managed to produce a very short
shower of large drops at about 2310Z. There was no evidence of
instability in the Sc/Ac from what I could see and the rain appeared
to fall out of essentially a clear sky. Could have been someone with
a hose but I don't think so as it lasted about half a mile of driving.
Another interesting aspect was the low dew point in the
afternoon, about 8°C, (measured, whirling psychrometer) showing the
air cannot have been of Atlantic origin but was being drawn in from
France.
The wind dropped markedly from S'ly F3-4 to less than F2 by
mid-evening and the temperature fell to a minimum of 15.5°C at about
2130Z but then rose to 18°C an hour later and has more or less stuck
there. The wind is all over the place, F1-2, mainly W'ly. Cloud 3/8
Ac or v high Sc.

Tudor Hughes, Warlingham, NE Surrey, 556 ft.