The California Highway Patrol said in a tweet that the freeway was reopened shortly before 3 a.m.
All lanes of the Grapevine are now open.— CHP Fort Tejon (@CHPFortTejon) February 11, 2019
Even after reopening, the CHP was running traffic escorts on the southbound side to keep speeds reduced. Meantime, no added snow was expected in the area for the rest of the day.
Caltrans tweeted news of the closure shortly before 8 p.m. Sunday.
⚠️GRAPEVINE ALERT: Interstate 5 is now 🚧CLOSED🚧 in both directions due to snow and freezing weather. @CaltransDist6 and @CaltransDist7 are working with our partners in the CHP to assess the safety of & to clear the highway. pic.twitter.com/TrvTxkzYB4— Caltrans HQ (@CaltransHQ) February 11, 2019
CHP Officer Nathan Krackey said some vehicles were stuck in areas that were closed.
"We also have some vehicles that are stuck in snow spots and they're trying to plow some of the roads and get some sand down to get those opened," he said.
Temperatures hovered in the mid- to upper 30s in the Castaic area, where the northbound part of the closure happened.
The closure came after a storm moved through the region, bringing bouts of steady and moderate rain to the Southland amid cold conditions on Sunday. Earlier in the day, there were reports of black ice on the roadway.
Around 4 p.m., snow began sticking to the ground and CHP paced the area.
More rain and snow are expected to hit the Southland starting Wednesday and it will be off and on throughout the week and into the weekend.