A wild weather ride is underway in the South as well as the Mid-Atlantic as Winter Storm Thor pulls freezing-cold air southward into a balmy air mass, bringing quickly changing weather conditions.

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Warmer temperatures surged north ahead of Winter Storm Thor, bringing hope of spring across much of the South. But those temperatures are crashing an arctic cold front pushes southward. In fact, many locations that are under winter storm warnings, watches or advisories have seen temperatures in the 60s, 70s and even lower 80s over the past 24 hours.

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Plummeting temperatures will cause rain to change over to freezing rain and even snow as Winter Storm Thor unfolds across the South through Thursday. The storm will continue to push east, producing an icy change over from rain into freezing rain then snow along I-95 in the Mid-Atlantic into the Northeast.

Southern Timing: Temperatures Plunge, Rain Turns to Ice and Snow

Southeast Radar

Winter Storm Thor: Thursday 7 AM

Current Temperatures and Winter Weather Watches/Warnings

(Winter weather alerts from the National Weather Service (shaded areas) along with current temperatures.)

WHEN: Thursday morning through Thursday eveningWHERE: Texas and Louisisana northeast into Alabama, Tennessee, and Kentucky east into the Carolinas and VirginiaIMPACTS: Icy and potentially dangerous road conditions from Austin, Texas to Shreveport, Lousiana into Huntsville, Alabama on Thursday morning. The threat for hazardous travel shifts east into South Carolina, North Carolina, and Virginia on Thursday night.

Much of the South saw temperatures drop 30 to 45 degrees in a 24-hour period thanks to yet another arctic cold front. In some cases, the plunge has been much more dramatic; for instance, Greenville, Mississippi, saw its temperature plummet 21 degrees in just 11 minutes early Wednesday afternoon, falling from 74 to 53.

Locations from to and have seen temperatures tumble during the 24-hour period on Wednesday. Rain transitioned to freezing rain and sleet late Wednesday night, and snow is expected to develop shortly thereafter. A winter storm warning has been posted for each city, where a few inches of snow may accumulate atop a thin glaze of ice.

Dallas, in particular, switched over to snow late Wednesday night, causing numerous automobile accidents on the interstates. In addition, heavy snow was reported just before midnight Thursday morning, with snowfall rates as high as 2 to 3 inches per hour for the Metroplex. Dallas-Fort Worth is expected to pick up as much as 3 to 5 inches of snow before Thor moves out of the region on Thursday.

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also experienced falling temperatures on Wednesday, causing rain to switch to freezing rain and sleet late on Wednesday night. The icy mix will then change to snow overnight. Snow accumulation forecasts can be found .

Farther north in rain and sleet changed over to snow late Wednesday evening. The snow will continue through Thursday morning. An accumulation of more than 6 inches looks likely in Louisville as well as much of the Ohio Valley.

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The rain is also expected to switch over to freezing rain as temperatures tumble below the freezing mark overnight into Thursday morning from to. The rapid fall in temperature may also cause any water on the roads from earlier rainfall to turn into ice, particularly on bridges and overpasses.

For those areas, precipitation is likely to end before the whole atmosphere is cold enough to force a changeover to snow.

Winter Storm Thor: Southeast Timing

(Forecast conditions over the next 12 hours for selected cities.)

Mid-Atlantic Timing: Soggy, Then Icy Conditions Along I-95

Current Mid-Atlantic Radar

Mid-Atlantic Winter Weather Alerts

A dangerous Thursday morning commute is likely for as well as , as the arctic air catches up with the heavy rain falling during the wee hours of Thursday.

In D.C., temperatures are expected to drop quickly from the 40s into the low 30s during the morning rush, causing rain to switch over to a wintry mix before completely falling as snow before lunch time. Snow is forecast to continue to fall through late Thursday afternoon, but tapering off before the evening commute. As much as 5 to 8 inches of snow is expected for the Nation's Capital through Thursday night.

An icy mix is also expected to occur from southern Virginia north into the Del-Mar-Va Peninsula Thursday into Thursday night.

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Further north, the switch over from rain to snow will occur sooner in Baltimore, and it is forecast to do so during the prime morning commute time. This change over will lead to hazardous travel, including but not limited to slush on roadways as well as slippery, icy conditions on untreated pavement. Snow is expected to taper off before evening, but Baltimore is also forecast to pick up as much as 5 to 8 inches of snow from Thor.

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In and , freezing cold air will surge east quickly enough to change rain over to snow well before the early fringe of the morning rush hour. Both cities are expected to pick up as much as half a foot of snow before the storm winds down Thursday evening.

In , light snow is expected to fall during the wee hours Thursday morning through Thursday afternoon. At 105.7 inches of total snowfall for the 2014-2015, Boston is ; however, the city is not expected to pick up much more than an inch from Winter Storm Thor.

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Winter Storm Thor: I-95 Timing

The fast changing weather will cause road conditions to change rapidly for the worse in many areas. Check back with weather.com and The Weather Channel for the latest forecast.

After Thor: Temperatures Keep Dropping

Behind Winter Storm Thor record-breaking cold will blast into the South through Friday. Numerous daily record low temperatures will be threatened both Thursday, Friday and Saturday morning. A few cities that could see record lows include, , and as well as , , and

Some locations may even see their coldest temperatures ever recorded so late in the season, including and where temperatures may drop into the single digits.

Places where heavy snow accumulates will be more prone to record-setting cold late this week because snow cover absorbs less energy from the sun during the day and radiates (loses) more energy to outer space at night.

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The cold temperatures after the snow will also mean less melting of any snow and ice that accumulates. Some locations may not see much melting until the weekend.

MORE ON WEATHER.COM: Winter Storm Thor Photos

An airplane slid off a runway at New York City's LaGuardia Airport on Thursday, March 5, 2015 during Winter Storm Thor. There were no reports of serious injuries. (Twitter/@NYPDSpecialops)