After a glorious Thanksgiving weekend of unseasonably warm days in the 60s and 70s, temperatures in the Bay Area are expected to come crashing back down to the point where you can no longer brag so much to your colleagues and relatives to the East.
The sun, which refuses to come out for more than ten hours per day at this point, is currently easing us into our frigid, bundled-up December, but things should get real chilly around Tuesday afternoon when a dry cold front will move in from Alaska. In the city this means overnight lows in the 40s and more days like today in the low 50s. Now that sunset happens before anyone can even think about stepping outside the office, commuters heading to the East Bay and Peninsula can expect to return home to lows in the mid-30s. The North Bay might even see some frost overnight in the second half of the week and through the weekend.
Further afield: ski resorts have started to open up in the Sierra but Squaw Valley only opened one chair over the holiday and the upcoming cold snap is only expected to bring less than an inch through the weekend on both the North and South sides of Lake Tahoe.