UPDATE (5:47 a.m.): The CHP is now reporting that all lanes of Southbound I-5 are clear and open.
The California Highway Patrol has started traffic breaks on the Southbound I-5 on the Grapevine.
According to the CHP's traffic website, the Nos. 1 and 2 lanes of Southbound I-5 just north of Frazier Mountain Park Road are iced over.
The traffic breaks are starting just north of Lebec.