European model simulation of a deep pool of cold air heading toward the East Coast from Thursday to Saturday.

After one of the warmest Octobers on record and 70-degree weather to start this week, the Mid-Atlantic and Northeast are in for a shock Friday and Saturday. Computer models have come into agreement that a major blast of Arctic air is headed south.

The penetrating pool of bitter air will first arrive in the Northern Plains on Wednesday before surging southeast through the Great Lakes on Thursday. By Friday morning, it will hit the East Coast, with cold air spilling across the Interstate 95 corridor from Washington to Boston.

Temperature difference from normal forecast Thursday through Sunday from GFS model.

Downwind of the Great Lakes and in interior New England, snow showers are likely to break out.

The core of cold will focus over the interior Northeast late Friday into early Saturday, with temperatures dropping up to 10 to 20 degrees below normal. Some of the coldest areas with respect to normal will include Syracuse, N.Y.; Burlington, Vt.; and Springfield, Mass.

By Saturday morning, freezing temperatures are expected from interior North Carolina northward.

Forecast low temperatures on Saturday morning from a GFS model. Note that these model projections are frequently several degrees too cold in urban areas.

Areas that have yet to experience a hard freeze along the Interstate 95 corridor from Richmond north are likely to see their growing seasons end by Saturday morning, including Washington, Philadelphia, New York and Boston.

While most of the area from Richmond to Baltimore is likely to witness freezing temperatures, downtown areas and locations near bodies of water might remain a notch above 32 degrees.

Afternoon highs on Saturday are likely to reach only the 40s in the Mid-Atlantic and the 30s in the Northeast.

Forecast highs Saturday from a GFS model.

This cold snap will not last long. By early next week, temperatures are predicted to return to near-normal levels, from 50s in the South to 40s in the North.