The National Weather Service has issued a dense fog advisory, which has been extended to 4 p.m. today.

Visibility will be one-quarter mile or less at times. This will delay your commute again this morning.If driving, slow down, use your low beam headlights, and leave plenty of distance ahead of you in case a sudden stop is needed.Today: Showers and possibly a thunderstorm before 3pm, then showers likely. Some of the storms could produce heavy rainfall. High near 46. East wind 9 to 13 mph becoming west in the afternoon. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.Tonight: Mostly clear, with a low around 27. West wind 10 to 13 mph.Saturday: Mostly sunny, with a high near 48. Southwest wind 5 to 10 mph increasing to 11 to 16 mph in the afternoon.Saturday Night: Partly cloudy, with a low around 28. Southwest wind 5 to 8 mph.Sunday: A chance of rain after 3 pm. Mostly cloudy, with a high near 47. West wind 6 to 8 mph. Chance of precipitation is 40%. New precipitation amounts of less than a tenth of an inch possible.Sunday Night: A chance of rain and snow before 7pm, then a chance of snow. Mostly cloudy, with a low around 21. Chance of precipitation is 40%. New precipitation amounts between a tenth and quarter of an inch possible.Monday: Mostly sunny, with a high near 31.