"Philip Eden" philipATweatherHYPHENukDOTcom wrote:

......(corrected dewpoint)
0850z WNW F2 30km 2Ac150 02.4/-04.0 1035.3
RMK: Ground semi-frozen. General hoar frost, now
melting quickly in the sun. An hour ago there had been
6Ac150 and 1Ac floc080, but the Ac has dissipated
rapidly, leaving behind lines of fall-streaks (looks like
Ci but clearly lower than some of the residual Ac)
aligned roughly N-S. Various halo phenomena, brightly
coloured but very abbreviated, on these lines including
one patch about 10deg from the vertical.

1220z NW F3-4 50km 1Cu024 06.3/-00.2 1034.8
RMK: Cu hum. Sadly the earlier interesting display
of fallstreaks and refraction phenomena disappeared
before I got my camera out

Philip Eden
Whipsnade 214m