Snow blog: See how the winter storm is impacting South Carolina

A winter storm is producing heavy snowfall and ushering in dangerously cold air across the mid-Atlantic in what could be the most significant system in more than a decade.

All of South Carolina’s 46 counties are under a Winter Storm Warning and an Extreme Cold Warning, which are in place because of the expected precipitation and dangerously cold temperatures.

Forecast models show widespread totals of 2 to 4 inches, with higher amounts, especially north of Interstate 26 and along the South Carolina–North Carolina border.

The greatest accumulations are expected in the region from Spartanburg through Rock Hill and over to Myrtle Beach. Some locales in this vicinity could approach double-digit snowfall totals.

All of the precipitation is forecast to move offshore by sunrise Sunday, leaving behind an Arctic air mass in its wake.

Temperatures during the second half of the weekend are expected to drop as low as 10 degrees across the Upstate, with wind chill values feeling closer to zero.

Forecasts warn that prolonged exposure to such cold conditions can induce frostbite and hypothermia in just minutes.

Temperatures are expected to remain below average through the week, with melting snow potentially leading to ice along untreated roadways during morning hours.

As the main surface low strengthens offshore, it is expected to undergo bombogenesis - a rapid intensification process when the central pressure drops at least 24 millibars within 24 hours.

The storm system will have the strength similar to a hurricane, so boaters are advised to remain in port until offshore conditions improve.

See the latest coverage on the winter storm in the live blog below.

Happening now:

South Carolina Department of Transportation crews are working around the clock to pretreat roadways. DOT officials say they have hundreds of personnel working to maintain approximately 41,000 miles of roadways.

Conditions are expected to deteriorate first along Interstate 85, followed by Interstate 20 around the lunch hour and later in the evening along Interstate 95.

Officials are urging residents to stay home on Saturday to allow crews the room they need to respond to issues.

“Unlike last weekend, there’s no threat of deadly ice damage and extended power outages – just slushy snow on roads and bridges that could freeze overnight. Stay off the roads unless absolutely necessary. As a precaution, last Wednesday’s state of emergency has remained in effect for this weekend," Governor Henry McMaster said in a statement.

You can check out road conditions and traffic updates at: https://www.scdot.org/travel/travel-road.html

Previous updates:

Friday, 9:15 p.m.
The initial round of flurries has begun moving into the Upstate.

The flurries are expected to remain light through the evening hours, with no accumulations before midnight.

Snowfall rates are expected to increase between sunrise Saturday and sunrise Sunday.

Based on forecast models, many weather observation sites in South Carolina are not expected to challenge their all-time snowfall records, but the storm system has the potential to rank among the top 10 snowfall events for some locales.