Repost of Jackone's post re. met office warnings....
Wales Ice
Issued at: 1627 on Sun 20 Jan 2013
Valid from: 0005 on Tue 22 Jan 2013
Valid to: 2355 on Tue 22 Jan 2013
As temperatures fall below freezing on Monday night into Tuesday morning icy stretches are likely on untreated surfaces especially in areas where any further sleet, snow or rain has fallen on Monday. In addition, further rain reaching the extreme southwest on Monday night may extend north and east on Tuesday across southern Britain readily turning to sleet and snow, giving further localised snow accumulation. However the extent of any wintry precipitation is very uncertain at this stage, The public should be aware of the risk of travel disruption.
Chief Forecaster's Assessment
Another night with icy surfaces as temperatures fall below freezing. However, a further frontal system may edge into southern Britain on Tuesday increasing the risk of further localised falls of snow. However, computer models are giving mixed signals regarding its extent so things remain very uncertain at this stage.