A Met Question??

[MightyGem]

What determines whether showers fall as soft hail or snow. We've had a lot of soft hail recently and with temps around 3 or 4 degC, I would have expected snow.

[Avalon]

Saturated adiabatic lapse rate probably? (I haven't a clue really..........!) Met Office have a good web site - ask them.

[JB007]

Don't claim to be Bill Giles....and I fluked my ATPL exam but I thought it was the cloud type.... .. .CB's large updrafts, able to support larger particles of precipitation i.e Hail...Snow is common from NS... .. .Errr, whats that Met Office web site..!??

[cossack]

Going back a long way to my Met course.... .. .Hail is formed by a process of accretion within a well developed CB when a droplet repeatedly falls and is then updrafted back into the cloud and attains another layer. This may happen numerous times, the more times, the bigger the hail. The temperature within the cloud because of its great height will be below freezing and so the droplet (hailstone) when it eventually falls to earth will not have time to melt. Hence hailstones on a summer day.. .. .Snow, however, is formed just like rain but in cold air, below 4C, and so falls as snow rather than rain. With snow there is no accretion, it just falls.. .. .I think that's about it but don't quote me on it! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />

[MightyGem]

Thanks for that guys. I had a feeling it was probably for that reason. Just wanted other opinions. <img border="0" title="" alt="[Smile]" src="smile.gif" />

[HEATHROW DIRECTOR]

Met Office.... is that the lot that have trouble deciding whether it's going to be dark at night?

[cossack]

Careful HD, Mrs C works for them but is NOT a forecaster!. .But in answer to your question, sometimes seemingly yes! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />