Relatives say the northwest Harris County mother would not just pick up and leave.
Alvarado was last seen March 30. She was leaving her job at Taco Bell on Texas 6 near Keith Harrow just after 3am.
Her car was later found close to her house.
"This is so unusual. We found her truck down Keith Harrow, just a couple of blocks away from her house, maybe four minutes walking distance. That's what got everybody's attention," Alvarado's niece, Marissa Ramirez said.
Alvarado is 5 feet 5 inches, 135 pounds and was last seen wearing her Taco Bell uniform.
The search for the woman picked back up at 8am along creeks, on back roads and in neighborhoods and bayous.
Homicide detectives are looking into this case. If you have any information, you're asked to call the Harris County Sheriff's Department at 713-967-5810 or Texas EquuSearch at 281-309-9500.