Thick, freezing fog will likely return to the Rogue Valley overnight and into New Year's Day, reducing visibility to one-quarter of a mile during the morning hours.
The predicted return has prompted the National Weather Service to issue a dense fog advisory from 2 to 10 a.m. that day. That means visibility will be significantly affected by the fog in areas throughout Jackson County.
The area's high temperature reached 49 degrees today. That and high clouds that helped to hold in the heat kept the fog at bay.
"It basically just dried out," said meteorologist Misty Duncan. "When you have cloud cover, it kind of acts like a blanket. Having the high clouds around really helped out."
But officials also expect low-hanging clouds to start rolling back in tonight.
Limited air movement means an air stagnation advisory will remain in effect until 4 p.m. Thursday. A weak system is expected to enter the area Thursday night into Friday and could bring some rain, but not much.
"It doesn't really look too strong for the Rogue Valley," Duncan said. "After that, we'll pretty much go back into our fog pattern again."
Tonight's fog and loitering air will wrap up the coldest December on record for Medford, with an average temperature of 31 degrees, the Medford office of the National Weather Service posted on its Facebook page. The previous record was set in 1972, when the average temperature was 31.5 degrees. The city also broke the record for the least amount of rain in a year, with 8.99 recorded inches. The previous record was in 1959, when 10.43 inches fall. The average rainfall total for Medford is 18.25 inches.
All records will be finalized at midnight.
— Ryan Pfeil