Blockbuster storm to bring heavy snow, ice and fierce winds in northeastern U.S. this weekend

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

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.

Enough snow will fall to make roads slippery and may cause school delays into Friday.

Meanwhile, a swath of wintry mix, including some ice, 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.

The blockbuster storm, which will hit the Midwest first, is likely to cause roads to close and lead to scores of flight delays and cancellations. Roads that may close during the storm 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.

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.

"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.

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

Related: Winter storm blasts U.S. Southeast leaving hundred of thousands without power

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

Just north of the mixed precipitation zone will be the heaviest rates of snow and the greatest overall storm total snowfall. An AccuWeather Local StormMax™ of 30 inches is possible along the storm's northern flank.

Following the wintry 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.

The same temperature surge is forecast to cause a period of ice or rain and snow mix from southern Pennsylvania to northwestern Virginia to parts of central New England and the Maine coast. While this may cut down on overall storm accumulation, a formidable winter storm with a substantial amount of snow is expected.

As the storm strengthens it will cause winds to increase. Winds may become strong enough to cause tree limbs to break and trigger localized power outages.

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.

As the cold air catches up to the storm, whiteout 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 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 Washington, D.C., 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 early 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.