Winter Storm Cara will impact much of the western and central United States through Thanksgiving weekend, spelling trouble for travel and other holiday plans.

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Here are six things to keep in mind about this third named winter storm of the season.

1. Large Part of the Country Affected

Snowfall Forecast

Cara will impact a broader area than recent winter storms Ajax and Bella.

Winter Storm Bella brought a narrow, yet heavy swath of snow from the Missouri Valley to Great Lakes last week, but Cara has already dumped snow from the eastern Oregon plateau and mountains of California into the central Rockies. More snow and ice has yet to fall from parts of the Texas panhandle, northward through the Plains and into the Upper Midwest and western Great Lakes.

In total, at least 21 states can expect some form of snow, sleet or freezing rain going forward from Cara.

The effects will go well beyond winter weather conditions. . Additionally, low clouds and fog may pose problems for .

2. Long-Duration Storm

Forecast Highs and Weather

This latest winter storm will be a slow mover, meaning it will take several days for Cara to move across the country.

Snow associated with the storm has already fallen Tuesday and Wednesday across parts of the West. On Thanksgiving, snow and ice developed over much of the Plains. As Cara only slowly moves east, the storm should continue through not just "Black Friday," but also into the weekend ahead.

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Cara's slow movement is related to a digging trough (dip) in the jet stream, which is forecast to become "cut-off" from the prevailing flow later in the week. As the upper-level low sits and spins over the center of the country, surface low pressure associated with the system will take several days to move from the Rockies to the Mississippi Valley.

Although it is still several days out, computer model forecasts suggest that it may not be until the middle of next week that energy associated with the system finally sweeps off the East Coast.

3. Holiday Weekend Travel Impacts

Friday's Forecast

(Areas of blue indicate snow, pink is a mixture of wintry precipitation, purple is ice and green is rain.)

Since the storm is moving so slow and will impact a large chunk of the U.S., travel plans will continue to be impacted through the holiday weekend over much of the country.

Through Friday, a large area of precipitation will develop and intensify from the Plains to the Midwest and Mississippi Valley, causing widespread travel concerns. Flight delays at several major hubs are likely, including , , and .

Numerous stretches of major interstates will become slick where snow, icy and/or heavy rain falls.

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Even where the precipitation is not particularly heavy, low clouds and fog could make travel by car or plane a bit slower than usual from the Rockies to the Great Lakes, southward to the western Gulf Coast.

Slow travel due to inclement weather conditions may continue through the weekend across parts of the southern Plains and Lower to Middle Mississippi Valley.

4. Season's First Ice Storm

Power Outage Potential

In addition to rain and snow, a swath of freezing rain may result in the first sizeable ice storm of the season in the Lower 48 states.

As cold air rushes south and gets trapped near the earth's surface, rain could freeze on contact, creating an icy glaze that makes not only traveling, but even walking a challenge. Where the layer of cold air in the lowest levels of the atmosphere is thicker, rain drops may freeze into ice pellets (sleet) before reaching the ground.

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The areas most likely to experience sleet and/or freezing rain, which may also mix with snow,includes a swath from Iowa and Nebraska into parts of Kansas, west and northwest Oklahoma, west Texas, including the panhandle and eastern New Mexico.

This does not appear to be a crippling ice storm with numerous power outages and widespread tree damage. However, many roads - not just bridges and overpasses - will become icy and at least some downed limbs and power outages appear likely in these areas.

5. Sandra May Play a Role

A Strange Weather Setup

Hurricane Sandra, is churning away in the eastern Pacific. If it wasn't enough to have a , Sandra could even become a factor in Winter Storm Cara's evolution.

Sandra is forecast to make landfall on the Pacific side of Mexico by Saturday. The mountains of interior Mexico will likely chew away at the storm system, causing it to rapidly weaken, much like what happened to Hurricane Patricia in October.

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Despite this weakening, at least some energy and moisture from Sandra is forecast to eject into southern Texas by late in the weekend. This may contribute to heavy rainfall over portions of the southern Plains and Lower Mississippi Valley.

It should be noted that the majority of the moisture feeding into Winter Storm Cara will have its origins from the Gulf of Mexico and not directly via Sandra. With that said, it is still an odd atmospheric setup to see a hurricane spinning just hundreds of miles away from a winter storm over the U.S.

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6. Arctic Blast Follows Cara

Forecast Lows

Cold, Canadian air will dive south behind Winter Storm Cara. The combination of an upper-level low spinning over the West and high pressure to the east will keep the cold air in place for several days.

This cold air will also plunge southward down the Plains through Black Friday.

Not only will the bitter blast hang around for a while, but for many, it should prove to be the coldest air mass so far this season by late this week and weekend.

Widespread daytime highs only in the 20s and 30s can be expected across much of the Great Basin, Rockies and Plains. Temperatures overnight could plunge to near zero degrees areas with fresh snow from Cara in the northern Great Basin and northern Rockies.

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Even coastal California won't escape some chilly conditions, with lows dipping into the 30s and 40s, including , and .

Record low temperatures could even be set in some of the aforementioned areas.

MORE ON WEATHER.COM: Winter Storm Bella (PHOTOS)

Vehicles move slowly on the road as snow falls Saturday, Nov. 21, 2015, in Wheeling, Ill. The first significant snowstorm of the season blanketed some parts of the Midwest with more than a foot of snow and more was on the way Saturday, creating hazardous travel conditions and flight delays. (AP Photo/Nam Y. Huh)