North Carolina has issued a Silver (Endangered Person) Alert for a missing south Charlotte mother and her daughter.

According to Charlotte-Mecklenburg Police, Megan Stack and her daughter, Ava, disappeared Monday afternoon after Ava was picked up from class at Bain Elementary School in Mint Hill. Authorities said Megan left her home on Cloister Drive around 1:30 p.m. Monday and has not returned or been heard from since.

A Silver Alert was issued for the 33-year-old Tuesday night. She is described as a white female, approximately 5-foot-4 with long blonde hair and green eyes. She was last seen wearing a maroon jacket with pants and black boots. Ava was last seen wearing purple jeans and a white t-shirt.

“Because of Megan Stack’s emotional state and recent behavior, there is serious concern for their safety,” CMPD said. While officials would not specify the nature of the concerning behavior or any medical issues, they said she has had concerning behaviors in the past.

According to investigators, CMPD's requested Amber Alert was denied by state authorities "due to it not meeting the restrictive criteria."

“My daughter Ava Stack is 8-years-old,” Ava’s father Timothy Lieberger said. “She’s my world. She’s everything to me. She’s all I have. She’s missing.”

The two are believed to be driving in a silver 2012 Hyundai Santa Fe with a paper tag. Authorities said they are unsure of their direction of travel.

“She’s driving, they don’t know where,” Lieberger said. “She’s in the car, they think, driving so please keep your eyes on the road.”

Anyone with information on Megan and/or Ava’s whereabouts is asked to call 911 immediately.