On Thursday, March 27, 2014 7:35:38 PM UTC, Norman wrote:
Bernard Burton wrote:



"Tudor Hughes" wrote in message

... A marked

thunderstorm starting 1332Z with many c-g discharges, one or two quite close

(about half a mile). More interestingly, the precipitation was mostly large

snow pellets, up to 20 mm, quite lumpy and hard but certainly not hail.

Outside it was like being pelted with white fudge. The total amount was not

large but enough to almost completely whiten the short grass in my back

garden. The temperature fell from 90C to 60C. The sky was yellowish (and

still is) with haze and had a distinctly summery look but other factors soon

gave the lie to that. A combination of late March sunshine a cold pool (524

dam) must be what set it off. I notice that showers broke out widely over

southern England and the Midlands from from about 10 a.m. onwards. Do I

call this snow? If so, that is 2 consecutive days in March with snow but

none in "winter".



Tudor Hughes, Warlingham, NE Surrey, 556 ft.







You raise an interesting point, Tudor. I have always been of two minds when

logging snow pellets. Officially, snow pellets come under the category of

'ice meteors', and are logged as such with small hail (ice pellets), snow

grains and diamond dust, hail itself being reserved for hail stones of 5mm

dia or more.



I made a note in my Observer's Handbook back in the 1970s against the

definition of snow pellets; 'snow or hail depending on size', and later in

the early 1980s; 'classed as hail provided that the hail pad is marked,

otherwise snow'. These definitions are not, I think, official, but just for

my own benefit, so that I do not have to agonise over how to classify them on

the rare occasions that they occur.



We recently had a fall of snow pellets on the 23rd, and these were up to

appx. 6 mm dia. At the time I thought I would call them snow, especially as

they produced a temporary covering on the roads etc. But when I returned

home, I found they had marked the hail pad well, thus changed my mind to

enter them under the 'small hail/ice' category.





The stuff that we had in Tideswell at about 1230z was very similar to what

Tudor described. I could best describe it as an agglomeration of frozen stuff

something like very big snowflakes but with a hardish centre. I didn't measure

it but Tudor's estimate of up to 20 mm sounds about right. The stuff came down

faster than snowflakes and slower than hail. On hitting the ground each

agglomeration disintegrated and instantly melted, not at all like hail. What

was striking was that there didn't seem to be any liquid water present even

though the temperature was over 6 deg. I've called it snow pellets though that

doesn't really describe it properly



--

Norman Lynagh

Tideswell, Derbyshire

303m a.s.l.

http://peakdistrictweather.org

Hail here in Dawlish and strong winds as the shower blew through. Hail, because on opening the window and sampling the damn stuff, it stayed as a, slowly melting, 0.5cm ice ball while I brought it downstairs to show the missus. Wild weather. Rain now, but the radar promises more wild stuff within the hour.