SAN DIEGO - A cold air mass lingering over San Diego County Friday morning prompted the National Weather Service to issue a freeze warning for inland valley areas, as five rural school districts remain closed because of icy road conditions.
Campuses in the Julian Union School District, Julian Union High School District, Mountain Empire Unified School District, Spencer Valley School District and Warner Springs School District were closed Thursday due to inclement weather and will remain closed Friday, according to the county Office of Education.
The freeze warning covers parts of the inland valleys -- including El Cajon, Escondido, La Mesa, Poway, San Marcos and Santee -- and was expected to expire at 9 a.m. Friday. Until then, meteorologists warned that extended exposure to the cold can cause hypothermia.
Temperatures in those areas could drop to the upper 20s Friday morning, forecasters said.
The freeze warning signifies sub-freezing temperatures that will kill crops and other sensitive vegetation and could harm outdoor pets and livestock.
NWS officials warned that roads could also be icy in spots.
As of 9 p.m. Thursday, a low-pressure storm system had dropped 14 inches of snow above 5,700 feet on Palomar Mountain over the past two days. In Julian, 9 inches of snow had fallen as of 2 p.m. Thursday.
Officials from Caltrans District 11 remind motorists who are attempting to get into the mountain communities to bring chains.