By Matt Peterson


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PHILADELPHIA (CBS) – An area of low pressure will affect the region on Wednesday and into Thursday morning. We will be looking at all precipitation types with this system – snow, sleet, rain, and freezing rain are all possible. A winter storm advisory will be in effect for Philadelphia, the surrounding suburbs and the Lehigh Valley from Wednesday morning through Wednesday night. A winter storm warning will be in effect for Chester, western Montgomery and Berks Counties from Wednesday morning through Wednesday night.

Timing

The system will advance from the south on Wednesday morning with snow starting south and west of the city in the mid- to late-morning hours. Snow will spread northeast across the region taking over the whole area during the afternoon.

Afternoon snow could be heavy at times. The prime time for heaviest snow will come in the 1 p.m. to 7 p.m. time frame. Precipitation is likely to remain through the evening overnight hours, as well. Expect lingering precipitation across most of the region through Thursday morning before we clear out after lunchtime on Thursday.

Thursday afternoon looks to be dry at this time.

Precipitation

We should expect all winter precipitation types with this system. Snow will be the primary precipitation type at the onset of the system on Wednesday morning and through the afternoon. Snow could be heavy at times in the afternoon and we should expect the bulk of the accumulating snow to fall through the afternoon hours on Wednesday.

As warm air advances in behind the snow, we will see temperatures warm enough that a transition to wintry mix and then to rain should take place through the evening and early overnight hours.

Rain will be the final precipitation type we experience before the system exits our region. During the transition from snow to rain, there will be the potential for some icing to occur with freezing rain falling in some areas.

Amounts

Right now the bullseye for the highest snow totals look to be west of the city – in areas like Chester, Berks, and western Montgomery Counties. In those areas, early snow estimates are in the 3- to 5-inch range.

Areas closer to the city and the I-95 corridor are expected to experience snow totals around 2 to 4 inches.

Across South Jersey, snow totals are expected to be around 1 to 2 inches.

Icing could be a concern as stated above and areas like the Lehigh Valley could even see some accumulating ice with even up to a couple tenths of an inch possible — depending on how long the transition to all rain takes.