A clipper-type system will move through Tuesday morning, bringing light snow to our area during the morning, ending early afternoon. The models often over-predict the amount of precipitation with theses systems (and very occasionally under-predict coastal development).

Both the GFS and NAM are predicting about 0.12 inches of water, falling as snow. With low temperatures, the ratio may be as high as 1:20, so 1-2 inches appears to be the case here. Again, clippers are notoriously underperforming from a snow point of view, so we will have to see if we really get that much.

Deep low pressure will intensify over the Great Lakes as it moves into Canada over the weekend.

Moisture moving over cold air during the morning on Saturday will initially result in snow and sleet around Philadelphia before turning to rain by noon. Light snow may begin as early as daybreak on Saturday, which is earlier than previously predicted.

Cold air at the surface will be slow to leave, making Saturday a cold and wet day. High will be near 40. Rain will be moderate to heavy Saturday afternoon and night.

An associated warm front will move through late Saturday night, but rain is likely to continue Sunday morning before tapering mid day Sunday. A cold front moves through late afternoon Sunday also accompanied by rain. High on Sunday mid 60s. Cold weather returns later Sunday night.

There’s a chance of light snow Tuesday.

A southwesterly flow of mild air will continue through early Sunday.  For Saturday,  a bit of clouds early morning, then mostly sunny skies and temperatures in the mid 50s.  Beautiful for December in Philly.

A cold front will move through during the day on Sunday. Sunday will be cloudy with showers likely during the afternoon and evening.  Temperatures still mild with highs near 49.

A broad trough will bring colder temperatures for upcoming week.  As mentioned in an earlier post, the cold front moving through on Sunday will stall not all that far to our south.  Disturbances may develop along this boundary.  The GFS suggests some light precipitation early Tuesday, otherwise dry.