UPDATE 6:00 P.M. – Memphis’ temperature has decreased to 21 degrees. Citizens can expect dangerous road conditions, wind gusts between 25 to 40 MPH and near-zero temperatures.

UPDATE 5:00 P.M. – Memphis’ temperature has dropped from 45 degrees to 29 degrees in the last hour.

MEMPHIS, Tenn. — Temperatures will drop about 45 degrees in a matter of hours as Arctic air moves in Thursday afternoon.

Expect “dangerously cold wind chills” Thursday night, the National Weather Service says. Some snowfall is also expected, though it will be a fast-moving system and not much will accumulate.

Wind chills could hit 10 or 20 degrees below zero thanks to northwesterly winds blowing a sustained 25 mph.

There is a Wind Chill Warning until noon on Friday for much of our area including Shelby County, and a Wind Chill Advisory for some of the counties in the southern portion of the viewing area.

Thursday will begin with temperatures in the 40s with some light rain showers. But by the afternoon, bitter cold starts moving from the west to the east, and the rain will change to freezing rain and snow by about 5 p.m.

By 7:30 p.m. Thursday, the precipitation will have moved through, but that’s when the real cold begins. Everyone in the News Channel 3 area will see temperatures in the teens and single digits.

Just before midnight, temperatures will bottom out at about 3 degrees in Memphis and may hit 0 degrees to the north in Blytheville.

With winds howling in from the northwest at 20 to 40 mph, the wind chill could make it feel like 10 to 20 degrees below zero by Friday morning.

Friday will begin with a temperature more than 40 degrees lower than just a few hours before. On Saturday — Christmas Eve — the high will be 28.

Most of the area will not climb back above freezing until early next week.

You’ll want to protect your pipes from freezing by wrapping them and leaving them dripping. Bring pets inside if you can and check on neighbors.

Powerful winds may blow down utility lines, leading to widepread power outages. In Shelby County, MLGW says it’s preparing for the challenge it expects from the weather.

Wednesday was the first official day of winter.