Will come into play tomorrow in the form of organised showers in NE england, though probably won't retain its identity as a PL.
There are a few factors at play here. Some diabatic heating from the PL, a convergence zone setting up as the NErly geostropic wind oversea meets the Nwerly ageostropic wind over land (sea breeze effects too). The result is the potential for locally hours of heavy snow, hence the amber warning.
The counterargument to that is that we will draw some slightly milder air that may turn the snow to rain anywhere exposed to that marine boundary layer and possibly even to lower levels inland later.
It could well be that initially NErn parts are most affected, but the risk transfers south and west as the maritime airmass penetrates inland. Alot of factors at play, difficult to predict.
Originally Posted by: Quantum