Unusual patterns of snow lying on paving

This forum is for comments about interesting weather of the day. Please create a thread for the day, or add your comment to the existing thread if it is related to previous comments there. By all means quote relevant numbers, but please do not post complete obs here.

Unusual patterns of snow lying on paving

Postby Peter Wright » 2015 Jan 15, 12:44

Wed Jan 14: We had a light fall of snow overnight; our patio looked like this at 0800. Can anyone suggest how these patterns formed? The large circles are all centred exactly on the spot where 4 slabs meet; the small circles are all centred exactly on the centre of each slab. I think it must be due to heat in the ground seeping up, but why in that pattern???Image
Edgmond, Nr Newport Shropshire. N Shropshire Plain, rain shadow of the Welsh hills, sheltered from all snow directions, exposed to Cheshire Gap showers, otherwise similar to rest of inland England.
Peter Wright
 
Posts: 55
Joined: 2011 Oct 07, 16:35
Location: Edgmond, northeast Shropshire

Re: Unusual patterns of snow lying on paving

Postby Len Wood » 2015 Jan 16, 23:37

Can only think that this pattern is something to do with the material the slabs were laid on affecting heat transfer from below.

Is this the first time you have seen this pattern?
How long have you lived there?
Did you lay the slabs or see how they were laid?

It looks as if concrete may have been used in laying the slabs, perhaps in circular splodges?
Len

Wembury, SW Devon coast
N50.33 W4.13
Altitude 83 m asl
Len Wood
 
Posts: 349
Joined: 2012 Jan 28, 16:12
Location: Wembury, coastal SW Devon, 83 m asl

Re: Unusual patterns of snow lying on paving

Postby Nick Gardner » 2015 Jan 17, 11:47

Len Wood wrote:It looks as if concrete may have been used in laying the slabs, perhaps in circular splodges?


Len, I was thinking the same thing when it jogged my memory that I have seen this before but it was with frost instead of snow. The melted parts represent the position of the 'blobs' of cement on which the slabs were laid. The warmth of the earth beneath conducts its way through these 'blobs' and through the slab and thus melts the snow.
Near Newton Poppleford, Sidmouth - Devon
50:41N 3:17 W; 20 metres AMSL; Station Grade B-BAAA37
http://www.ottervalley.co.uk
Nick Gardner
 
Posts: 429
Joined: 2012 Jan 27, 17:25
Location: Rural riverside valley location near the village of Newton Poppleford and 2 km from the sea.

Re: Unusual patterns of snow lying on paving

Postby Peter Wright » 2015 Jan 19, 22:10

Thanks Len & Nick, I came to the same conclusion independently. The contractor who laid them probably used the method of putting a dollop of cement on each corner and a dollop in the centre.

That's the crucial factor. I have not seen this before; it was also relevant that the snow thickness was sufficiently slight, and also that the ground was probably several degrees above freezing since we had had mild weather of 10-14C on 3 preceding days.
Edgmond, Nr Newport Shropshire. N Shropshire Plain, rain shadow of the Welsh hills, sheltered from all snow directions, exposed to Cheshire Gap showers, otherwise similar to rest of inland England.
Peter Wright
 
Posts: 55
Joined: 2011 Oct 07, 16:35
Location: Edgmond, northeast Shropshire


Return to Daily discussion



Who is online

Users browsing this forum: No registered users and 1 guest

cron