But wouldn't that depend on the precipitation being heavy, and the relative humidity being low enough to take on board some of the latent heat? I'm more thinking of the returning polar-maritime air after the pre-frontal continental air has been nudge out, i.e. the air mass behind the [warm] occlusion/sector.



On Monday, January 14, 2013 9:52:34 AM UTC, Freddie wrote:
Will, wouldn�t cold air from the west have to be cold thru

the depth, since there won�t be a surface inversion layer? I would guess

an 850mb temperature of -6c would produce at best a sleety mix. You

would need to go down to -8c before getting proper snow. Are we likely

to see such cold air from the

current set up?



Don't forget that cooling from latent heat effects will be pronounced at

times in these frontal battlegrounds, producing deep isothermal layers

around melting point - so rules of thumb using temperatures 5000 feet up in

the atmosphere need to be used with care.

--

Freddie

Bayston Hill

Shropshire

102m AMSL

http://www.hosiene.co.uk/weather/

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