Latest Snow Estimates, Timing For Winter Storm In PA

UPDATE: Snowfall estimates have increased in Eastern Pennsylvania.

EASTERN PENNSYLVANIA, PA — Forecasters with the National Weather Service have extended a winter weather advisory in Eastern Pennsylvania, with all counties now impacted.

Wintry mixed precipitation is expected throughout the Philadelphia region Sunday and Monday, with about an inch of snow possible. Four inches or more could fall in the northern areas of the state.

The winter weather advisory is in place through 1 a.m. Tuesday.

Forecasters predict a "long duration storm" with two waves of winter weather.

On Sunday, forecasters expect a mix of snow, sleet, and ice. A lull in precipitation is possible Sunday evening.

Rain and sleet will continue Monday morning, mixing with snow later in the day.

The details of precipitation type, change-over time, and snowfall and ice amounts remain unclear, however, as it will depend on the specific timing and location of transition from rain to snow.

The hazardous conditions could impact the morning or evening commute Monday. "Travel could be very difficult," the National Weather Service said in the advisory.

Significant snowfall amounts are possible north of I-78.

Here is the latest accumulation prediction map:

Here is the forecast for the Philadelphia region:

Today: Freezing rain likely before 10 a.m., then rain. High near 41. East wind 9 to 13 mph. Chance of precipitation is 100 percent. Little or no ice accumulation expected.

Tonight: Rain. Low around 35. North wind 9 to 14 mph. Chance of precipitation is 90 percent. New precipitation amounts between a quarter and half of an inch possible.

Monday: Rain and sleet before 8 a.m., then rain, snow, and sleet between 8 a.m. and 9 a.m., then rain and snow after 9 a.m. High near 36. North wind around 9 mph. Chance of precipitation is 80 percent. New snow and sleet accumulation of less than a half inch possible.

Monday Night: A chance of snow before 1 a.m., then a chance of snow showers between 1 a.m. and 4 a.m. Cloudy, with a low around 29. North wind 9 to 11 mph. Chance of precipitation is 50 percent. New snow accumulation of less than a half inch possible.

Tuesday: Mostly sunny, with a high near 40. Northwest wind 9 to 13 mph.

Tuesday Night: Mostly cloudy, with a low around 29.

Wednesday: Mostly cloudy, with a high near 43.