The first of two winter storms to hit San Diego County with chilly temperatures, rain, mountain snow and gusty wind in the final days of 2016 moved into the region Friday.
The first bout of low pressure brought rain with a slight chance of thunderstorms to most areas throughout the day.
The National Weather Service expects rainfall amounts from the first bout of inclement weather to range from a quarter to half an inch, with more on higher mountains. Forecasters predicted the storm would drop .21 of an inch of rain in Borrego Springs; .24 in San Diego; .30 in the Miramar area; .34 in Escondido; .35 in Alpine; .37 in Alpine and Ramona; .42 on Mount Laguna; .48 in Julian; and .59 on Palomar Mountain.
Forecasters said rain showers may linger overnight ahead of a stronger, colder storm set to move into the region from the northwest on Saturday. A winter weather advisory for the mountains will extend from 4 p.m. Saturday to 6 a.m. on New Year's Day. Forecasters are warning of poor visibility, high winds and possible road closures in mountain areas on New Year's Eve.
Snow is expected in the mountains at 6,000 feet Saturday afternoon and could reach as low as 4,000 feet late that evening, the NWS said. Forecasters expect 2 inches to accumulate below 5,000 feet and up to 8 inches on higher mountain peaks.
Up to a foot of snow is expected in the San Bernardino County and Riverside County mountains.
Inland and at the coast Saturday, light rain is expected to turn to moderate to heavy downpours in the afternoon, according to the NWS.
Afternoon high temperatures are expected to fall to about 10 degrees below average by the end of the week.
Winds of 20 to 30 miles per hour with gusts to 50 mph are expected in some mountain locales, according to the NWS.
The storm is expected to dissipate late Saturday night, but wind conditions will likely persist into the new year, forecasters said.
The San Diego County Department of Environmental Health also issued a warning Friday, telling swimmers, surfers and other ocean users to avoid all coastal waters for 72 hours following the rain due to the potential for elevated bacteria levels.
Water contact at the Tijuana Slough National Wildlife Refuge and Border Field State Park is prohibited until sample results indicate the ocean water is safe. County officials also said the access road to Friendship Park should be avoided because of "sewage-impacted" runoff on the road.
