Winter Storm Avery will impact the South, Midwest and Northeast late this week.
Rain, snow or a wintry mix of sleet and freezing rain are all possible precipitation types.
A damaging ice storm is possible in parts of the Appalachians.
This could lead to messy commutes and flight delays Thursday and Friday.
Winter Storm Avery is spreading a mess of rain, snow and ice into parts of the mid-Mississippi Valley, Ohio Valley and soon into the East. Conditions will go downhill across the Appalachians and Northeast on Thursday.
Winter storm warnings, watches and winter weather advisories have been posted for parts of a number of states from Arkansas and northern Mississippi into the Ohio Valley, Appalachians and Northeast.
Warnings are issued for areas where confidence is high that heavy snow, sleet and/or freezing rain are expected to produce a significant impact. Watches are posted for areas where significant impacts may occur, but forecaster confidence is not yet high.
Freezing rain, sleet and/or snow will make travel hazardous for areas under a winter weather advisory.
Avery was initially named with the expectation that winter storm warnings would be issued for at least 2 million people, and this criterion was reached when much of the mid-Mississippi region, including the St. Louis metropolitan area, and the central Appalachians were placed in warnings by late Wednesday morning.
Light snow was reported in Greenville, Mississippi, some sleet was reported in Tupelo, Mississippi, and sleet had mixed with drizzle briefly at the National Weather Service office near Jackson, Mississippi.
Accumulating snow was observed early Wednesday in the Monroe, Louisiana, metro area, smashing a long-standing record there.
According to the National Weather Service, at least 0.1 inches of snow was recorded in Ouachita Parish near Monroe Regional Airport, shattering its record earliest-in-season measurable snow by 10 days, previously occurring as early as Nov. 24, 1950.
Snow had also accumulated on vehicles in El Dorado, Arkansas, and flurries fell for a time early Wednesday morning in Memphis, Tennessee.
Snow or a wintry mix of sleet and freezing rain will spread northeastward into the Ohio Valley during the evening hours.
A mix of freezing rain and sleet will then break out Wednesday night in the Appalachians, Shenandoah Valley and adjacent Piedmont.
Rain is expected elsewhere in the Southeast and the southern mid-Atlantic region.
Snow or a mixture of rain, snow, freezing rain and sleet will stretch from the mid-Mississippi Valley into the Ohio Valley, eastern Great Lakes, Appalachians and Northeast into southern New England Thursday.
This could potentially include a brief round of snow near or just northwest of the Interstate 95 corridor, including Boston, New York City, Philadelphia, Baltimore and Washington D.C.
Damaging accumulations of freezing rain are possible in eastern West Virginia, western Virginia, western Maryland and parts of southwestern and central Pennsylvania.
Rain is expected farther south across the Southeast and the southern mid-Atlantic region.
A quick changeover to snow showers is possible in much of Kentucky, Tennessee and the southern Appalachians.
Strong winds may also develop along the Eastern Seaboard as the area of low pressure intensifies.
Snow remains possible from the Poconos of northeastern Pennsylvania to central and upstate New York and northern New England.
Precipitation is expected to fall in the form of rain along the East Coast from southern New England to northern New Jersey before ending from south to north through the day.
Snow may continue in parts of northern New England Friday night before tapering off by Saturday morning. However, lake-effect snow could develop in the Great Lakes snowbelts by Friday night or Saturday.
Avery Snow/Ice Potential
The best chance of moderate to potentially heavier snowfall totals is in a swath from central Pennsylvania to New York state and western and northern New England. Another area near the upper-level low in the mid-Mississippi Valley could pick up moderate to locally heavy snowfall, possibly up to 6 inches in spots.
Making this forecast tricky is the potential for either sleet, freezing rain or even rain to penetrate into these areas at least for a time.
Accumulations of ice that could at least slicken roads and overpasses are expected from the Ohio Valley into the Appalachians, parts of Pennsylvania, northwestern New Jersey and southern New England.
More damaging ice accumulations capable of tree damage and power outages are expected in the Appalachians, from south-central Pennsylvania into northwestern Maryland, eastern West Virginia and western Virginia.
This could make the commutes both Thursday and Friday somewhat challenging in these areas. This could also lead to flight delays at the major Northeast airport hubs, even if rain dominates.
Check back with us at weather.com for updates to the forecast.
A potent disturbance in a southward plunge of the jet stream will pivot from the lower Mississippi Valley to the Northeast through Friday.
This will trigger development of a second area of low pressure at the surface near the East Coast. Steered by that jet stream dip, the low will track northeastward Thursday into Friday.
With some cold air in place, this system will produce snow, sleet and/or freezing rain from the mid-South to the mid-Mississippi Valley, Ohio Valley and a rather sizable swath of the East.
In most of the interior Northeast away from Interstate 95, cold air should hold in place to keep the precipitation types predominantly of the wintry variety, either snow, sleet or freezing rain.
Closer to Interstate 95, an initial round of wintry precipitation should eventually change over to rain.
Strong winds may also accompany this storm as it moves through the Northeast Thursday and Friday.