SAN DIEGO (CNS) - The second winter storm to roll across the region in a week is expected to drop moderate but steady rain throughout San Diego County Thursday and bring a slight chance of thunderstorms in coastal areas, forecasters said.

The low-pressure atmospheric system sweeping through Southern California is expected to keep producing local showers through late Thursday night, according to the National Weather Service.

In a 24-hour period ending around 3 a.m., the storm had dropped around a half-inch of rain in Fallbrook and Oceanside, seven-tenths of an inch in Escondido, three-quarters of an inch in Ramona, eight-tenths of an inch near the San Diego International Airport, six-tenths of an inch in La Mesa and around a half-inch in San Ysidro, according to the NWS.

Before making its exit Thursday night, the storm will drop up to an inch along the ocean shoreline, around three-quarters of an inch in the western valleys, up to one and one-quarter inch in the mountains and up to a half-inch in the deserts, forecasters said.

Isolated thunderstorms will be possible in coastal areas Thursday before the storm system moves northeast out of the region late Thursday night, NWS meteorologist Miguel Miller said.

Father Joe's Villages and Connections Housing Downtown will provide free inclement weather sheltering Thursday for San Diego's homeless residents. Check-in at Father Joe's begins at 4 p.m., and the shelter can hold up to 250 people. Check-in at Connections Housing downtown begins at 5:30 p.m. and the shelter can hold up to 30 people. Meals will be provided for sheltered residents.

The county Department of Environmental Health has issued a general rain advisory, warning residents to avoid contact with water at all coastal beaches and bays from Seacoast Drive to the U.S.-Mexico border due to this week's rainfall. Urban runoff can be exacerbated due to significant amounts of rain and lead to heightened amounts of bacteria in bodies of water. 

County officials advise residents to avoid water contact for 72 hours after the rainfall ends. The shoreline of Tijuana Slough National Wildlife Refuge and Border Field State Park will also remain closed due to Tijuana River flows contaminated with sewage entering U.S. waters. 

Residents can visit or call the county's beach information hotline at (619) 338- 2073 for more information.