Market Street shoppers will be treated to the illumination of nearly 100 5-foot-wide snowflakes -- adorned with energy-efficient LED bulbs -- decorating the "Path of Gold," a row of street lamps that line the historic shopping district between Second and Fifth streets.
The snowflakes will be turned on during an official ceremony at 6 p.m. and will stay on through mid-January.
The ceremony takes place at the cable car turn-around at Market and Powell streets.
Mayor Gavin Newsom is expected to attend, as are officials from event sponsors Pacific Gas and Electric Co. and the San Francisco Convention and Visitors Bureau, joined by "snowflakes" from the San Francisco Ballet Company's production of "The Nutcracker," worn by San Francisco Ballet School students.
The city's tourism and business communities hope the illuminated snowflake displays will attract more visitors to the downtown shopping area.
The idea was developed by the Market Street Association, a nonprofit established in 1963 to promote the redevelopment of the Market Street corridor.