We're expecting just a nuisance tonight, but the blockbuster storm, which will hit the Midwest first, is forecast to evolve into an all-out blizzard, cause roads to close and lead to scores of flight cancellations.

The second of two storms this week will be a blockbuster in terms of impact from dangerous blizzard conditions with a foot or more of snow forecast to fall from northern Pennsylvania to upstate New York and northern New England this weekend.

Nuisance storm to race through first

The first storm, forecast to swing quickly from west to east spanning late Thursday to Friday morning, will be more of a nuisance with up to a few inches of snow from Pennsylvania to central and northern New England.

For forecast snowfall accumulation with the major storm this weekend, see below.

Enough snow will fall to make roads slippery and may cause school delays into Friday. In most areas snowfall from the storm will be on the order of an inch or two.

Meanwhile, a swath of wintry mix will occur from near and just south of the Mason-Dixon Line to much of New Jersey and southern New England.

A much more dramatic, disruptive and dangerous storm will follow approximately 36 hours later from Saturday to Sunday. Errands should be completed before the storm hits.

Blizzard, ice storm to shut down travel over interior Northeast this weekend

The blockbuster storm, which will hit the Midwest first, is forecast to evolve into an all-out blizzard, cause roads to close and lead to scores of flight cancellations.

Those who are on the road through the heart of the snow area will be at risk for becoming stranded for many hours and may have to face temperatures plummeting to life-threatening low levels.

Roads that may close during the storm in the Northeast include portions of Interstate 79, 80, 81, 86, 87, 89, 90 and 91. At times snowfall rates in this zone may be 2-3 inches per hour as blizzard conditions unfold.

Plows are not likely to be able to keep up. As the storm strengthens, winds will cause major blowing and drifting of snow, where ice does not mix in.

An AccuWeather Local StormMax™ of 40 inches projected in parts of northern New England. Close to 30 inches of snow is likely to fall on parts of central and northern New York state to perhaps the northern tier of Pennsylvania.

Snowfall of 12-24 inches is likely to be more common in the heaviest band from the storm. But, blowing and drifting at the height and conclusion of the storm may cause the snow depth to vary by several feet.

While the heaviest total accumulation of snow from the storm will fall north of the Interstate 95 cities from Washington, D.C., to Baltimore, Philadelphia, New York City and Boston, enough wintry precipitation can occur in the heart of the cities or just northwest to cause slippery conditions and major travel disruptions.

"A quick burst of snow and ice on the front end of the storm from late Saturday to Saturday night may cause roads to rapidly become slippery in the I-95 swath from the upper mid-Atlantic to southern New England," according to AccuWeather Chief Meteorologist Elliot Abrams.

Around the New York City and Philadelphia areas, a few inches of snow may be followed by a buildup of ice before plain rain occurs.

A southward or northward shift in the storm track by as little as 50 miles may have a profound impact on temperatures and snowfall versus ice accumulation since a heavy rate of precipitation is expected during the height of the storm, Abrams added.

A storm that tracks a few dozen miles farther south may bring heavier and longer-lasting snow or ice into the I-95 corridor. A storm that tracks a bit farther north may cause more rain, ice and less snow farther north.

The storm has the potential to cause a buildup of ice that exceeds 0.25 of an inch from parts of northern Virginia to along the South Coast of New England. This is enough to bring down trees and power lines.

Where ice accrues to a thickness of 0.50 to 1 inch, widespread power outages can be expected.

Just north of the mixed precipitation zone will be the heaviest rates of snow and the greatest overall storm total snowfall.

Following the icy mix near the coast and in parts of western Virginia and Maryland, drenching rain and rising temperatures late Saturday night to Sunday morning may be enough to cause urban flooding problems.

As the storm strengthens it will cause winds to increase. Winds may become strong enough to cause tree limbs to break and trigger power outages. A widespread power outage situation is most likely where snow and ice have been clinging to the trees as winds pick up. In some cases, this may not be until precipitation from the storm has ended.

Just as the southerly winds will bring warm air in near the coast for a time, northerly winds will occur on the storm's northwestern flank. Gusts between 35 and 50 mph can occur as the storm strengthens and then moves away.

As the cold air catches up to the storm, all-out blizzard conditions, extensive blowing and drifting snow and a rapid freeze-up of slush are forecast to transpire from the eastern Great Lakes to the central Appalachians and central and northern New England. Motorists are encouraged to not underestimate the severity of conditions that may unfold in these areas. Vehicles may become stranded and occupants would be subject to plummeting temperatures, which are expected to reach dangerously low levels.

The rapid temperature plunge will also be a shock along the coast, where temperatures are likely to plummet from the 40s F to near freezing on Sunday and then into the single digits and teens on Sunday night.

There is a chance the cold air catches up on the back side of the storm at a fast enough pace to cause a period of accumulating snow in the I-95 corridor from Philadelphia to New York City and Boston.

Regardless, any areas of standing water and wet areas will freeze in the wake of the storm. Removal of slush and snow should be prompt to avoid the glued-down effect and dangerous conditions for motorists and pedestrians for several days.

Failure to do so may require an excessive amount of expensive ice-melting compounds as rock salt may be ineffective during the upcoming Arctic blast.

For people in wooded areas that are prone to power outages during major storms, an alternative source of heat should be considered. There are health dangers associated with wood-burning fireplaces, so be sure to take precautions if you plan on heating your home this way.

In the wake of the snowstorm, bands of heavy lake-effect snow may persist downwind of lakes Erie and Ontario into early next week. Fiercely cold winds are likely to persist through Monday in the central Appalachians, into Monday night in the coastal mid-Atlantic and into Tuesday in New England.

School delays and closures are likely into next week due to the amount of snow on the ground across the interior and the cold conditions farther south and east in the region. Gusty winds may continue to cause flight delays through Monday.