As much of the nation prepares for last-minute holiday shopping and preparations, a storm will bring a plethora of precipitation to the country starting with the Southwest

This storm system will bring a threat foraccumulating snow from Chicago to DetroitTuesday before shifting into the East on Wednesday.

While meteorologists are still hammering out the details as new data comes in every few hours, one thing is for sure...this whole mess of weather is starting to begin in the Southwest.

What Will Cause the Winter Weather?

A storm system currently spinning near the California/Arizona border will begin to move eastward tonight through Monday. As this occurs, the storm will tap into a little more in the way of tropical moisture.

Rain and high-elevation snow will develop into tonight from Arizona through New Mexico before translating into the western half of Texas overnight.

At first, snow levels in the Southwest will begin rather high, around 7,000 feet through this evening, but as the storm shifts into the southern Plains, it will begin to draw colder air southward.

Rain will become steadier and heavier late tonight into Monday morning across northern Texas, Oklahoma and southern Kansas. As the aforementioned cold air mixes in, it will cause snow levels to crash, effectively changing the rain to heavy snow by Monday afternoon from Amarillo, Texas, through Guymon, Okla., and Dodge City, Kan.

Farther to the south, strong thunderstorms could affect cities from Dallas to Houston Monday afternoon and Monday evening.

How Much Snow Will Fall?

As far as snowfall accumulations go, the higher elevations of the southern Colorado Rockies through the Sangre de Cristo mountains of northern New Mexico could receive 6-12 inches of new snowfall before all is said and done.

Farther east, in some of the more populated zones, a swath of 6-12 inches will be the rule from southeastern Colorado and northeastern New Mexico through the Texas and Oklahoma Panhandles into southwestern Kansas. Cities such as Guymon, Dodge City, and Dalhart lie in this zone.

A narrow area in the aforementioned zone could see over a foot of snow. Snow will come down heavy at times with rates up to 2"/hour creating near-blizzard conditions.

Farther south, snowfall amounts will taper off quickly as you get into milder air. Even so, Amarillo will get in on the accumulating snow, picking up between 3 and 6 inches of accumulation.

Rain changing to snow will start to translate northeastward into Monday night, bringing accumulations to Kansas City, Topeka and Manhattan...Kansas that is!

Through Monday night, the cities mentioned above will receive a general 1-3 inches of snow.

Tough Travel Expected

According to Meteorologist Alex Sosnowski, "It is likely that slippery areas will develop this evening and progress to the east over the high ground along I-40 in Arizona and New Mexico. As snow spills out over the southern High Plains tonight and Monday, snow is likely to fall and accumulate in part of I-40 stretching across the northern Texas Panhandle and Route 54 reaching northeastward into southern Kansas."

Not only will the snow make for slippery travel, but brisk winds will develop late tonight into Monday across the central and southern Plains.

Significant blowing and drifting of the snow is expected across this region with northeast winds gusting to between 40 and 50 mph!

Detours, delays and road closures are all possible tonight and Monday. So, if you are heading out for last-minute shopping, be sure to take it slow and keep an eye on road conditions.

Wild weather will shift farther east Tuesday and Wednesday, bringing snow chances from Chicago to Detroit through northern New England.