The National Weather Service of San Diego issued a dense fog advisory starting at 5:26 p.m. Friday to 6 a.m. Saturday for San Diego County's coastal areas, including Oceanside, Vista, Carlsbad, Encinitas, Chula Vista, National City and San Diego.
The fog reduced visibility for the Carlsbad and Miramar areas to 1/4 mile; visibility at Imperial Beach was at 3/4 mile and 7 miles at the San Diego International Airport, according to the NWS.
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Visibility will likely lower tonight as the fog is expected to move inland, the NWS added.
Severe weather across the nation is causing many flights to be delayed or cancelled Friday night at San Diego International Airport in the middle of one of the most hectic and popular travel times of the entire year.
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The Christmas rush is on and packages have also been delayed getting to their destinations.
FedEx, UPS, the United States Postal Service and Amazon were all seeing delays due to extreme winter weather across the U.S.