It's hammer time as far as meteorologists go, so let's give you the most accurate forecast we can.

The set-up

A storm system will move into the Kentucky and West Virginia region by late tonight. Its center will jump to the coast as a secondary storm rapidly intensifies off the Virginia coast. On the western flank the coldest air in 20 years will start to be drawn into the storm's circulation. Meaning snow will expand rapidly into Philly shortly after 7 to 8 p.m. Winds will increase and temperatures will plunge. Significant snows will accumulate rapidly during the night as roadways become extremely hazardous .

The saving grace keeping us from a burial will be the quick-moving nature of the storm.

Timing

Today should just see some sporadic snow showers, mixed with rain mainly across southern New Jersey and Delaware. Temperatures - 30-35 degrees.

Tonight: 10 p.m.-4 a.m.: The brunt of the storm and accumulating snow.

Temperatures nosedive into the teens and winds rapidly increase leading to blowing and drifting of the snow, along with dangerous wind chills of zero to 20 below.

Friday morning: Leftover snow showers, light additional accumulations but plenty of blowing and drifting of the snow.

Friday afternoon: Dry, windy and bitterly cold, with some blowing of the fluffy snow. Temperatures in the teens.

Snow accumulations anticipated

(Still subject to change as storm has yet to form. It's a storm that has a high bust potential.)

Philly: 4-6 inches with a low level chance (30-40 percent) of more than 6 inches.

Southern Bucks County: 6-9 inches, with a 30 percent chance of more than 9 inches.

Montgomery, Chester, and northern Bucks counties: 4-8 inches.

Lehigh Valley: 5-9 inches

Poconos: 5-10 inches (with a 30 percent chance of more than 10 inches).

Southern New Jersey: 4-6 inches.

Jersey Shore: 2-4 inches.

Central and northern Delaware: 4-6 inches.

Southern Delaware: 2-4 inches.

Moderate coastal flooding along central and northern New Jersey shores.

Southern New Jersey: Minor flooding ... ALL by Friday morning.

John Bolaris