Bolaris: Philly dodging a snow bullet?
As a winter storm approaches the Philadelphia region, computer models have shifted the highest snow amounts east of the I-95 corridor. Right now, it looks like the city of Philadelphia will escape the heaviest snow. Parts of Southern New Jersey and Delaware will not. The snow bulls-eye will be central and southern Delaware and across southeast New Jersey, where Cape May County will take the brunt.
The set-up
A polar front is moving through central Pennsylvania. Behind the front, heavy snow is falling across southern Ohio and stretching into southwestern Pennsylvania as temperatures nosedive into the teens. Ahead of the front, milder temperatures have moved in meaning any precipitation that starts here will fall as rain through the 9 p.m. hour tonight.
The northwest suburbs - across western Montgomery, Chester and upper Bucks counties and into the Lehigh Valley - will see a mix to snow with 2-3 inches of snow by late tonight.
The first wave of energy will move through tonight and as it does, any rain will be changing over to sleet, freezing rain and then to snow between 10 p.m.-1 a.m. This will produce icy roadways throughout the Delaware County by late tonight and during the overnight period. We could pick up a couple of inches of snow overnight if the changeover happens quickly enough.
A second energy bundle - and the more potent one - with a lot of Pacific and Gulf of Mexico moisture will surge northeastward across Virginia, Washington, D.C. and Maryland by early Monday morning.
Along this heavy band, 8-12 inches of snow will fall.
The polar vortex, which will rotate around unleashing super cold air over us, will actually help to suppress the second storm system on a more easterly course
This should steer the heavy snow band south and east of Philadelphia across southeastern New Jersey and central and southern Delaware. This will be the axis of the 8-12 inch snow amounts.
Timing
4-9 p.m.: Rain moves in mixed with snow and sleet and some freezing rain northwest of city, as well as western Chester, northwest Montgomery and Upper Bucks counties.
After 9 p.m.: Rain or mix changes over to a period of freezing rain not extensive) then all snow after midnight.
Monday morning rush: Hazardous travel as many roads will be snow-covered and icy. A few inches of snow will be on the ground, especially across central and southern Delaware.
Moderate snow will be falling across the city, with moderate to heavy snow increasing as you head south and east from the Delaware River.
A sharp-cut-off in snow amounts and intensity across northwest Chester, western Montgomery and Upper Bucks counties and into the Lehigh Valley.
Heavy snow banding will take place through mid-day across southeast Atlantic County and Cape May County in New Jersey.
Heavy snow at the same time will be falling across central and southern Delaware from Dover points south.
After 10-11 a.m. Monday morning: Any steady accumulating snow will taper off in Philadelphia and all points north and west.
11 a.m.-2 p.m.: Light snow to flurries.
3 p.m.: Dry, but extremely cold temperatures will hold in the teens.
Snow totals (by 3 p.m. Monday)
SOUTHEASTERN PENNSYLVANIA
Northeast Philly: 3-6 inches
Center City: 4-6 inches
South Philly: 5-7 inches
Delaware County: 4-8 inches
Southeast Chester County: 5-8 inches
Western Chester: 4-6 inches
Western Montgomery: 4-6 inches
Upper Bucks: 4-6 inches
Lower Bucks: 5-7 inches
Lehigh Valley: 3-6 inches
Berks County: 3-6 inches
NEW JERSEY
Western Camden: 4-8 inches
East Camden: 6-8 inches
Salem: 6-9 inch inches
Mercer County and North Burlington: 3-6 inches
Cumberland County: 6-10 inches
Gloucester County: 6-10 inches
Cape May County 8-12 inches, with a few spots exceeding 12 inches
Eastern Atlantic County: 8-12 inches
Western Atlantic County: 6-10 inches
Atlantic City: 4-6 inches
Ocean County Southern: 6-10 inches
Ocean County Northern: 4-8 inches
DELAWARE
New Castle: 6-8 inches
Kent and Sussex: 8-12 inches plus
Poconos: 2-4 inches ... go figure.
John Bolaris