PHILADELPHIA (CBS) -- Expect a sunny start to the work week with a pleasant winter day on tap for Monday, as highs climb into the mid to upper 40's. But conditions turn from sunny to soggy as a slow-moving storm system approaches by midweek.

Showers are possible across the areas as early as Monday night and we'll need the umbrella in hand on Tuesday with periods of rain to continue through the day.

With high temperatures rising well-above average, into the mid 50's, the precipitation will fall as all rain on Tuesday--the exception will be in the Poconos where a period of freezing rain is probable early Tuesday morning and light ice accumulations are possible.

The latest models are indicating a trickier picture for Wednesday. As opposed to previous runs, Wednesday now appears to be mainly dry during the daytime hours, with a secondary surge of moisture not arriving until Wednesday night as the system's cold front makes approach.

The presence of this moisture in combination with colder, arctic air spilling in on the backside of the system could yield the threat for snowfall, possibly accumulating, in the Delaware Valley late Wednesday into early Thursday morning.

Stay tuned to the evolving forecast!