01:17 Making Snowflakes Any Time of the Year The Weather Channel meteorologist Kelly Cass looks at how you can make a snowflake any season of the year.

At a Glance The next big weathermaker will arrive in California Friday night with rain and Sierra Nevada snow.

Snow will spread eastward this weekend across the Rockies, central Plains and Ohio Valley.

This system will then spawn an area of low pressure near the Northeast coast.

The track of the low will determine what areas in the Northeast see significant snow. An expansive swath of snow, and some ice will spread across the West, Plains, Ohio Valley and Northeast through this first weekend in March, potentially including some East Coast cities that have seen relatively little snow recently.

You've found an old forecast. For the latest on what is now Winter Storm Scott, please read out latest article.

This wintry system won't charge across the northern Plains and up into the Great Lakes like the last several storms. Instead, this weekend storm track will involve areas farther south in the Plains and Ohio Valley, rather than what we saw for much of February.

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/staticmaps/DCT_SPECIAL101_1280x720.jpg" srcset="https://s.w-x.co/staticmaps/DCT_SPECIAL101_1280x720.jpg 400w, https://s.w-x.co/staticmaps/DCT_SPECIAL101_1280x720.jpg 800w" > Forecast Into the Weekend (A wintry system will leave a trail of snow as it moves from the West Coast to the Ohio Valley this weekend. It will bring snow to parts of the Northeast Sunday into Monday.)

Winter storm warnings are in effect for parts of the Sierra, Colorado high country and southern Wyoming, including Cheyenne.

The National Weather Service has issued a number of winter storm watches and winter weather advisories from the mid-Mississippi Valley into the West, including the cities of Denver, Kansas City and St. Louis. Winter storm watches are also in effect in parts of the Northeast.

Forecast Timeline

Friday Night

By late Friday evening, moisture will begin to flow into much of California in the form of lower-elevation rain and Sierra Nevada snow above 5,000 to 7,000 feet.

Overnight, snow will spread eastward across the central Great Basin and central and northern Rockies into the central and northern High Plains.

Some areas from northern Colorado and southern Wyoming eastward to western Nebraska might have periods of moderate to heavy snow.

Saturday

Snow will stretch eastward into the central Plains by the afternoon, then eastward to the mid-Mississippi and lower Ohio valleys during the evening and overnight hours.

On the southern fringe of that snow, there could be a narrow zone of sleet and/or ice from the Texas Panhandle eastward through the Ozarks of Missouri and Arkansas by Saturday evening.

Winds are expected to increase by Saturday night in the Plains, which could lead to some blowing and drifting snow, in some areas.

Temperatures will also plummet behind this system, as one of the coldest March air masses in several years plunges into the Plains and Midwest.

(MORE: Arctic Chill on the Way)

Sunday

The storm will impact the Northeast Sunday into early Monday, but the forecast there is a bit trickier.

An area of low pressure will develop, but its exact track will be the key for determining who gets snow, where the most snow falls and who gets rain.

Computer models are still painting an array of tracks, which is not unusual a few days out, from a track that is near the Interstate 95 corridor on the northern end of the spectrum to a track that takes the low from North Carolina to off the East Coast on the southern end.

A more northern track would bring rain, possible gusty winds and some coastal flooding to the major cities along the East Coast, while the more southern track could bring more snow to the coast.

The confidence in this part of the forecast is lower because of these differences, but the dividing line between rain and snow and snowfall amounts will be sorted out over the next day or so as forecast guidance comes into tighter agreement. So, check back with us at weather.com for the latest updates on this forecast.

(MORE: Is It Too Late to Get a Strong Nor'easter?)

Snowfall Forecast

West

This system will not be as wet as the last couple of systems and will likely only bring less than an inch of rain to most of California. Parts of the central California coastal ranges and southern Sierra foothills may see more than an inch of rain, however.

In the higher elevations, 1 to 2 feet of snow is likely in the central and southern Sierra, while the central Rockies, northern Sierra Nevada and Utah's Wasatch Front may measure 5 to 18 inches of snow, depending on elevation.

Central and East

Parts of southern Wyoming, western Nebraska, Kansas, Missouri and southern Illinois have a good chance of picking up 5 inches or more of snow.

It's still too soon to determine exact snowfall amounts from the Ohio Valley into the Northeast, due to the aforementioned uncertainty in the track of surface low pressure.

At least moderate snowfall amounts are expected in the Ohio Valley, and some part of the Northeast is expected to pick up heavier amounts of 6 inches or more later Sunday into Monday.

Whether that heavier Northeast snow footprint lies closer to the coast or farther inland, with more rain near the coast, remains uncertain.

For now, here's an outlook showing what locations we think could see light or significant snow accumulations. This forecast will likely change; check back frequently for the latest forecast update.