Snow to Meltwater Ratio

[arbocop]

If you have 15cm of snow, what is the equivalent proportion of water once melted?

 

I've heard 3/1 but that sounds too much.

 

Does anyone know?

 

 

ps Weather is rubbish in Berkshire again! Might get out at the weekend, but it's likely to be very local.

[chesters1]

If you have 15cm of snow, what is the equivalent proportion of water once melted?

 

I've heard 3/1 but that sounds too much.

 

Does anyone know?

 

 

ps Weather is rubbish in Berkshire again! Might get out at the weekend, but it's likely to be very local.

 

should be easy enough to find out get a pint of snow then melt it ,snow as it fell not crammed in mind

[Chris Plumb]

The rule of thumb is 10 inches of snow to 1 inch of water - last weeks snow may have been even 'fluffier'. The guy on the Thatcham weather site melted the snow in his rain gauge (circa 8 inches) and got 17mm of precipitation.....

 

 

C.

[arbocop]

The rule of thumb is 10 inches of snow to 1 inch of water - last weeks snow may have been even 'fluffier'. The guy on the Thatcham weather site melted the snow in his rain gauge (circa 8 inches) and got 17mm of precipitation.....

 

 

C.

 

 

Thanks Chris, that's useful.

 

Mike

[Anderoo]

Interesting, I was wondering that too.

 

It's now starting to thaw again here in Oxford. Plenty of rain coming on Saturday apparently, with a warmer (7*C!) and sunnier day on Sunday, so the weekend might be alright after all. I really hope so, I want to explore more of that little river and tempt a few of its turbo-charged chub.

[Brian Carragher]

One and a half inch's to 15 cms of snow

[Toady]

I recall the 10:1 ratio for fresh fallen snow too. More to the point if we get a massive thaw how much is in 'Them Thar Hills'? I can see the mother of all floods coming.

[Will Wilkinson]

The bigger problem is not the volume of water contained in the melt, but the fact that the underlying ground is likely to still be at least semi-frozen. This greatly increases the problem of run-off as nothing's absorbed by the frozen soil. I'm expecting to see a fair bit of flooding at the weekend as slightly milder air moves in (for a while - this winter's not over yet), particularly as this is likely to be accompanied by moderate rain.

 

The ratio of snow depth to equivalent rain is very variable - the light powder that we had last week doesn't produce much when melted - could even be as high as 15:1 if it's very powdery, but the much wetter stuff that fell in the last 24 hours (here at least) might only be 5:1.

 

Will

Edited January 13, 2010 by Will Wilkinson

[The Flying Tench]

The bigger problem is not the volume of water contained in the melt, but the fact that the underlying ground is likely to still be at least semi-frozen. This greatly increases the problem of run-off as nothing's absorbed by the frozen soil. I'm expecting to see a fair bit of flooding at the weekend as slightly milder air moves in (for a while - this winter's not over yet), particularly as this is likely to be accompanied by moderate rain.

 

The ratio of snow depth to equivalent rain is very variable - the light powder that we had last week doesn't produce much when melted - could even be as high as 15:1 if it's very powdery, but the much wetter stuff that fell in the last 24 hours (here at least) might only be 5:1.

 

Will

 

Well let's take 10:1 as a reasonable average. I'm sure glad we have frequent thaws in UK. If a typical winter's rainfall (say 12") all fell as snow and was all lying on the ground before any melted we'd have 10 feet of snow! I'm starting to see the advantage of a long rod!

[Kappa]

I recall the 10:1 ratio for fresh fallen snow too. More to the point if we get a massive thaw how much is in 'Them Thar Hills'? I can see the mother of all floods coming.

 

Exactly! All that snow plus about 2 and a half inches of rain early next week. Add that all up and you get equivalent of 4 inches of rain in a week!

 

Rich