Graham P Davis wrote:

Mike Hatton wrote:



Norman wrote:
Darren Prescott wrote:

Here is a summary of the NWP output for noon on Wednesday.
Issued 0550, 15th March 2008

The latter half of the working week will see a change to much
colder conditions over the UK, as low pressure moves SE'wards
over the North Sea. At this time of year, the flow is likely to
be very unstable, with heavy (and wintry) showers possible
anywhere. Over the higher ground of the north the showers are
likely to fall as snow and there's a chance (albeit a much lower
one) of snow pretty much anywhere. Settling snow is unlikely away
from the north, however, due to the strength of the sun at this
time of year.
Though there have been many notable cases at this time of year and
later with heavy accumulations after dark. One that springs to
mind was on or about 20th April in, I think, the late 1970's when
there was an accumulation of 2-3 inches even in Central London

Norman

11 April 1978 [about 0800]

10.0 cm at Hornchurch.
OS TQ 5386

Similar at Bedford too.

I think the point that Darren was making about snow not settling due
to the strength of the sun was because we're dealing with showers
here and the sun will quickly heat surfaces and prevent snow
settling. In situations where snow is prolonged, and occurs before
the sun has warmed the ground, snow has been seen to settle as late
as June (2/6/1975 in East Anglia).


If I remember correctly, the 1978 event resulted from a line of showers
that moved south across SE England during the evening, a couple of
hours after sunset.

Norman
--
Norman Lynagh
Chalfont St Giles, Buckinghamshire
85m a.s.l.
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