The cold will first settle southward over the West during the latter part of this week into the weekend. Portions of California may experience their lowest temperatures of the season so far with a hard freeze. Temperatures are likely to moderate slowly later next week in the West.

It is possible the string of cold nights this weekend into the first part of next week rivals that of the past several decades in part of the Southwest.

Phoenix, Ariz., could rival its four consecutive dates with temperature readings of 32 degrees or lower set most recently during late December of 1988. Average low temperatures this time of the year for the city are around 45 degrees.

A three-day stretch of 32-degree or lower readings occurred spanning Dec. 11, 2010, through Jan. 2, 2011, with lows of 32, 30 and 32 degrees respectively.

Farther east, arctic air will spill into the northern Plains this weekend from central Canada and will progress slowly eastward in stages through next week.

Multiple storms could ride up from the Gulf of Mexico along the edge of the cold air slowly advancing over the Midwest and lower Mississippi Valley. It is possible that it will take a larger storm to finally drive the cold air to the coastal Northeast during the middle of next week.

While it appears the cold will not rival the great arctic outbreaks of January 1994, December 1989 and January 1985 in terms of severity, it is possible that temperatures will plunge 40 to 50 degrees over a 24- to 48-hour period as some locations pass from a warm air mass to the arctic air over the northern Plains.

For example, Fargo, N.D., is projected to have a high temperature well into the 30s on Thursday, Jan. 10, but during the evening of Saturday, Jan. 12, temperatures may plunge below zero.

Nasty Cold Heading for Part of the U.S.

Warmup, Thaw Precede Brutal Cold

Farther east over the Midwest, the cold air may advance and stop several times as storms roll up from the southwest.

For the central Plains to the lower Ohio Valley, the mid-Atlantic and places on south, the arctic air may only be around for a few days before Pacific air mixes in from the west.

In New England, it will take longer for the cold air to take root. However, once it does arrive, it could be difficult to get rid of. There is some indication that steering-level winds, known as the jet stream, could dip southward over the region for an extended period aside from a few wobbles.

In New York City, the latest trends are that the coldest weather may not arrive until late next week into the weekend of Jan. 19 and 20 and the cold may be somewhat abbreviated. This is due to a persistent area of high pressure near the southern Atlantic coast.

According to Chief Meteorologist Elliot Abrams, "Long-range temperature forecasts have a strong root to climatology, or normal/average, so that arctic outbreaks and their low-level cold air may be washed out by this basis."

The core of the cold air and the center of high pressure does not appear to be aiming for the Deep South, due to the persistent high offshore in the Atlantic.

In central Texas, there may only be a couple of nights where temperatures get low enough for borderline frost or freeze conditions and that is highly contingent on cloud cover, wind direction, etc.

More details on the cold air and adjustments to temperatures will continue in the coming days on AccuWeather.com.