By Lauren Casey

PHILADELPHIA (CBS) — A Winter Storm Watch has been issued by the National Weather Service for Philadelphia and surrounding suburbs, Berks County, the Lehigh Valley and Poconos from 7 a.m. Wednesday until 7 a.m. Thursday as a powerful Nor’easter is set to impact the region.

Confidence continues to increase that significant snowfall will occur across a large portion of the area. At least six inches of snow is possible along I-95 and areas west with totals of a foot or more possible.

It is not out of the question that 18-plus inches of snow falls in the vicinity of our far northwest suburbs, Berks and the Lehigh Valley, as it stands currently.

Snow, along with strong winds, some coastal flooding, and bitter cold to follow, will present multiple hazards. Steady and heavy snow is likely to impact much, if not all, of southeastern Pennsylvania.

The consensus in recent guidance indicates that the rain/snow line will set up over southern New Jersey.

One factor that could preclude Philly and near-by New Jersey suburbs from seeing very significant snowfall would be an intrusion of warmer mid-level air which could yield a period of heavy sleet as opposed to snow Wednesday night. However, as of now, it does not appear this air will reach that far north.

At present, it looks as though this event could be in the top 10 for the biggest one-day December snowfalls in Philadelphia on record.

Precipitation commences by midday on Wednesday and wraps by midday Thursday. The heaviest snow falls Wednesday night into Thursday morning when gusty winds will also be affecting the region.

Snow at the shore will mainly arrive at the tail end of the event late Wednesday night and Thursday morning.

High snowfall totals in many areas coupled with gusty winds could lead to power outages.

Additionally, bitter cold will prevail following the storm’s exit. Sub-freezing temperatures on Thursday and Friday will not yield much melting.

This means snow-covered and icy road conditions could persist for up to several days following the event.

Overnight lows now look to fall into the teens for late-week and wind chills could be near 0 in parts of southern New Jersey by Saturday morning.

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