will impact a large swath of the country from the mid-South and Ohio Valley to the East Coast starting Thursday. Here are six things you need to know about the storm today.

1.) Hardest Hit Areas May See Up to 2 Feet of Snow, But Northern Extent of Heaviest Snow Uncertain

Snowfall Forecast

(Forecast snowfall accumulations for Jonas.)

We are confident that parts of the East will see more than a foot of snow from Winter Storm Jonas, particularly in the Mid-Atlantic states. It's not out of the question that some locations will see up to 2 feet of snow. This includes parts of eastern West Virginia, western Virginia and possibly portions of the Washington, D.C., and Baltimore metro areas.

There is less confidence in how heavy the snow amounts will be the farther north you travel along the I-95 corridor, including from New York City to southern New England. Snowfall amounts in this swath will be dependent on the exact track of the area of low pressure associated with Jonas.

From Pennsylvania to southern New England, there may be a wide range of snowfall totals across a short distance. The heaviest totals are mostly likely in the southern end of this area, with lighter amounts farther north.

You can find our latest forecast thinking on snowfall amounts for Jonas .

2.) There is an Ohio Valley and South Snow and Ice Threat Too

Winter Storm Jonas Alerts

Jonas is not just an impactful storm for the East Coast, it will also bring significant snow and ice to parts of the Ohio Valley and South starting as early as Thursday.

Accumulating snow is possible from parts of central Arkansas to northern Mississippi, Tennessee, Kentucky and northwestern North Carolina Thursday night through Friday. Parts of northern Alabama and northern Georgia may see rain change to snow Friday night with some light accumulations possible.

In addition to snow, there may also be some corridors where locally significant freezing rain (ice) accumulations occur. Right now, this includes locations from northeast Arkansas to southeast Missouri, Kentucky, southern West Virginia, western and central North Carolina, upstate South Carolina and far southern Virginia. Although the ice could certainly impact travel, there may also be areas that see tree damage and power outages, particularly in North Carolina and southern Kentucky.

3.) First Blizzard and Winter Storm Watches Have Been Issued

Winter Storm Jonas Alerts

The National Weather Service (NWS) issued the first blizzard watch for Jonas on Wednesday morning for parts of northern Virginia and central Maryland. This includes Washington, D.C., and Baltimore where the NWS warned that travel is likely to be impossible Friday night into Saturday.

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As of Wednesday night, winter storm watches had been issued as far west as eastern Arkansas, northern Mississippi and Tennessee to as far east as New Jersey, Delaware, central and southern Virginia and North Carolina.

4.) Increased Weather Data May Lead to Increased Forecast Confidence

The position of the energy that will be responsible for spawning Winter Storm Jonas is outlined in white over the western states on Wednesday morning.

The upper-level energy that will be responsible for spawning Winter Storm Jonas was spinning over the central United States as of Wednesday night.

Given that the system is now over a region that has more upper air and surface weather observations for computer forecast models to ingest, this may in turn lead to an even more confident forecast in the next 24 hours.

In addition, NOAA will be launching extra weather balloons over the next couple of days at six-hour intervals rather than the typical 12-hour intervals done in calmer weather periods. Those extra weather balloons will be launched in much of the central, southern and eastern United States and will provide extra data about the atmosphere aloft to help improve weather forecasts.

5.) Don't Forget About the Overshadowed Threats From Winter Storm Jonas

Power Outage Potential

(Areas in the darkest purple shading are most likely to experience power outages due to snow or ice and wind from Winter Storm Jonas)

Although much of the focus is on how much snow and ice will fall from Winter Storm Jonas, don't forget about the potential for power outages and significant coastal flooding.

If you live anywhere from eastern Virginia to New Jersey and Long Island, take the necessary steps to be prepared for power outages. Winds could locally gust up to 60 mph in some locations on Saturday, which combined with the snow accumulations, may down power lines and tree branches.

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This winds will also contribute to low visibility and dangerous or impossible travel conditions Friday night through Saturday.

In addition, coastal flooding continues to be a serious threat for coastal locations due to the onshore winds. This will exacerbated by higher than normal tides from a full moon this weekend.

Areas of particular concern include:

Delaware, including both Delaware Bay and the Atlantic beachesThe western side of Chesapeake Bay, including tidewater inlets and the Norfolk/Newport News metro areasThe Jersey shore, including the south shore of Raritan Bay

For more details, .

6.) Washington, D.C., Sees a Snowstorm of a Foot or More About Once Every Eight Years

An unidentified man pushes a car out of the snow January 7, 1996 in Washington, D.C. (BOB PEARSON/AFP/Getty Images)

, Washington, D.C. has seen three-day snowfalls of a foot or more 16 times since 1884, which works out to about once every eight years.

The nation's capital has only seen two snowstorms over a three-day period of 20 inches or more in its history, and only one storm has dumped over 2 feet.

We're not saying Jonas will bring those extreme snowfall totals to Washington, D.C., but it provides some perspective on heavy snowfall events in the Mid-Atlantic region.

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