Philadelphia weather: Rain arrives Monday night, snow accumulation possible Tuesday morning

PHILADELPHIA (CBS) — The Super Bowl has come and gone, and now we’re looking ahead to a storm system set to affect the entire area Monday night into Tuesday. While everyone will be impacted, the Lehigh Valley, Poconos and Philadelphia will just see more of the winter side of the storm.

Expect to see another cloudy day Monday, but temperatures will remain relatively mild with a high near 50 degrees in Philadelphia, 47 at the Jersey Shore and 49 in the Lehigh Valley.

A developing area of low pressure will continue to strengthen as it moves across the Tennessee Valley on Monday. With that, expect increasing clouds and showers that will develop late in the afternoon toward the early evening, eventually turning into a snow event for parts of the Delaware Valley on Tuesday, which we’ve designated a NEXT Weather Alert Day.

Winter Weather Alerts

A Winter Storm Warning goes into effect at midnight until 3 p.m. Tuesday for much of northeastern Pennsylvania and has extended into central Bucks County.

In lower Bucks and Montgomery Counties, a Winter Weather Advisory will remain in effect until 3 p.m. Tuesday.

Storm timing

Since temperatures will be well above freezing and close to 50 degrees in the city, this storm will start as an all-rain event for everyone, even in the higher elevations of the Poconos.

Rain will gradually get heavier and steadier in the late evening and Monday night.

By midnight Tuesday, colder air holding back toward the west will eventually start to move in, turning some of the rain to snow by 2 a.m. across the Poconos.

The northernmost areas have the greatest chance for decent snow accumulations through Tuesday morning. In the Lehigh Valley and the Poconos, 8 to 12 inches of snow may accumulate, with the highest totals across Carbon and Monroe Counties.

Elsewhere, areas south like Philadelphia will see a changeover to slushy, wet snow around 6 a.m. that will struggle to accumulate, due to the relatively warm ground and temperatures close to 40 degrees during the day. Here, a trace to potentially 2 inches of snow is likely, with that higher end reserved for areas well north and west of the city.

Still, it could be snowing for the better part of a few hours between 7 a.m. and 10 or 11 a.m. before the system moves out.

Snow forecast headlines CBS Philadelphia

Farther south and east – areas like Delaware and the Jersey Shore – will get plain, old rain from this event, with heavy rain possible Tuesday morning.

Impacts on the Tuesday morning commute will be felt everywhere, even in the rain-soaked locations. Remember to leave early, slow down and avoid large areas of water on the roadways.

Behind the heaviest precipitation Tuesday morning, we’ll see the winds kicking up, gusting between 30 and 40 mph during the afternoon. A Wind Advisory may be issued for this timeframe – stay tuned.

For the shore, moderate coastal flooding is possible with high tide Tuesday morning. Because of this, a Coastal Flood Watch is in effect for Atlantic and Burlington Counties at the shore, with 1-2 feet of inundation possible.

Cooler and drier weather is on the menu for Valentine’s Day Wednesday, with seasonably cool highs and partly cloudy skies on tap for the rest of the week. Temperatures Wednesday morning will be in the upper 20s to near 30 degrees, which will create some concern for melting snow and residual water freezing on roadways and walkways. By Wednesday afternoon, temperatures will climb back above freezing with highs near 40 degrees.

Your 7-day forecast:

7-day forecast for Feb. 12, 2024 CBS Philadelphia

Monday: Increasing clouds, showers arrive around sunset. High 51.

Monday Night: Rain showers at first then a transition to snow late. Low: 36.

Tuesday: NEXT Weather Alert Day – Wet snow in the morning, ending through the afternoon. High: 40.

Wednesday: High of 39, low of 31, windy and cold

Thursday: High of 43, low of 26, partly sunny

Friday: High of 43, low of 34, mostly sunny

Saturday: High of 42, low of 31, shower chance

Sunday: High of 44, low of 28, partly sunny