6:00 AM | **Major snowstorm possible at week's end**

00Z GFS total snowfall forecast by later this weekend; map courtesy Weather Bell Analytics

6-Day Philly Forecast

Today

Partly sunny, windy, very cold, chance for a snow shower or two, highs in the mid 20’s

Tonight

Partly cloudy, breezy, bitter cold, chance for a snow shower, lows in the low-to-mid teens

Tuesday

Mostly sunny, still brisk and very cold, mid-to-upper 20’s

Tuesday Night

Mainly clear, quite cold, upper teens

Wednesday

Increasing clouds, still quite cold, low 30’s; chance for some light snow at night

Thursday

Mostly sunny skies, cold, low-to-mid 30’s

Friday

Cloudy, cold, chance for snow and it could be a major snow event, low-to-mid 30’s

Saturday

Cloudy, cold, chance for snow and it could be a major snow event, low-to-mid 30’s

Discussion

Earlier last week, some spots in the I-95 corridor received their first snowfall of the season as numerous snow showers broke out with an Arctic frontal passage. Yesterday, other areas received their first snow this winter as a period of steadier snow associated with a coastal low produced accumulations of a dusting near the big cities and a few inches at the New Jersey coastline (Atlantic City 2.8"). You get the feeling the momentum has shifted and winter is saying "I am back". Indeed, winter could return in full force later this week as there is potential for a major snowstorm at week's end. The atmosphere has evolved in recent days to one with high-latitude blocking across Canada and Greenland which is providing the cold air for the eastern US and an active "El Nino-enhanced" southern branch of the jet stream to provide the moisture. The next couple of days will be very cold as yesterday's Arctic frontal passage ushered in some of the coldest air of the season so far. As a result, afternoon temperatures will generally be confined to the 20’s for the next couple of days and it doesn’t look like a quick warm up during the mid-week time period either as colder-than-normal conditions should persist. A light snow event is possible around here during Wednesday night and then the potential exists for a major snowstorm in the Friday/Saturday time frame from a storm that will pull out of the Mississippi Valley and heads towards the Mid-Atlantic coastline. One final note - and as far as winter's momentum is concerned - there are signs for another big storm late next week. Stay tuned.