A bank of dense fog over San Francisco and the Bay wreaked havoc Thursday morning, causing several car accidents in and around SF.
The fog posed several challenges during the early morning commute, limiting visibility to a quarter mile or less and causing lights to become reflective and distracting before the sun rose in the morning. That prompted an advisory from the National Weather Service telling commuters not to use their high-beam headlights, and to move with extra caution.
*** #FOG UPDATE***— NWS Bay Area (@NWSBayArea) January 20, 2022
The Dense Fog Advisory has been expanded to include the North Bay Valleys, the San Francisco Bay Shoreline, as well as the City of #SanFrancisco - in addition to the waters of the Bay. Vis as low as 1/4 mi.
The Advisory is through 10 AM LST.#CAwx #CAfog pic.twitter.com/EVtohUeXpj
Video on the Citizen App shows the fog was so thick, lights on the Bay Bridge reflected off of it, causing blinding rays to shoot out toward drivers and limiting visibility. Low visibility conditions likely contributed to a vehicle crash in the westbound lanes at around 6 a.m, per CBS.
Citizen App users also reported several highway crashes, including one along eastbound I-80 near 7th Street, and another accident on northbound 101 near the on-ramp to I-80. The latter is reported to have blocked traffic in the northbound lanes of 101 in San Francisco.
The fog, which also moved in Wednesday morning but to a lesser degree, wasn’t expected to clear out until late morning Thursday.
The weather service's Dense Fog Advisory affects North and South San Francisco bay, the North Bay Valleys, the Bay Shoreline, and the City of San Francisco.