Stable conditions under a ridge of high pressure resulted in areas of dense fog developing in the San Joaquin Valley each night from December 7 through 11.
On the evening of December 7, the dense fog began in the center of the valley from Merced to Hanford, then spread throughout the valley after midnight with widespread visibility less and 1/4 mile except at Fresno and Bakersfield. Visibility lowered to less than 200 feet at times, resulting in the California Highway Patrol pacing traffic on area highways. The fog cleared by mid-morning on December 8.
Dense fog redeveloped quickly after sunset on December 8, and became widespread during the evening, including the Fresno and Bakersfield areas. Parts of Kings and Kern counties had near zero visibility. There were many school bus delays due to the fog. The dense fog lasted until around noon.
The was a repeat of the dense fog on the evening of December 9 lasting until mid-morning on December 10. As a storm system approached the area bringing clouds across the region on afternoon of December 10, dense fog was limited only to the south end of the San Joaquin Valley, where visibility in Kern County fell to less than 1/4 mile for a only few hours, lifting around 2 am.

Dense Fog in SE S.J. VALLEY, CALIFORNIA
From 09-DEC-14 15:55:00 to 10-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in SE S.J. VALLEY, CALIFORNIA
From 10-DEC-14 23:20:00 to 11-DEC-14 01:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in E CENTRAL S.J. VALLEY, CALIFORNIA
From 08-DEC-14 17:45:00 to 09-DEC-14 13:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in E CENTRAL S.J. VALLEY, CALIFORNIA
From 09-DEC-14 22:00:00 to 10-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in SW S.J. VALLEY, CALIFORNIA
From 09-DEC-14 17:56:00 to 10-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in SW S.J. VALLEY, CALIFORNIA
From 08-DEC-14 17:45:00 to 09-DEC-14 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in SE S.J. VALLEY, CALIFORNIA
From 08-DEC-14 19:15:00 to 09-DEC-14 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in W CENTRAL S.J. VALLEY, CALIFORNIA
From 10-DEC-14 02:00:00 to 10-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in W CENTRAL S.J. VALLEY, CALIFORNIA
From 08-DEC-14 02:00:00 to 08-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in E CENTRAL S.J. VALLEY, CALIFORNIA
From 07-DEC-14 21:35:00 to 08-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in SW S.J. VALLEY, CALIFORNIA
From 08-DEC-14 02:00:00 to 08-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in SE S.J. VALLEY, CALIFORNIA
From 08-DEC-14 07:00:00 to 08-DEC-14 09:30:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Dense Fog in W CENTRAL S.J. VALLEY, CALIFORNIA
From 08-DEC-14 21:22:00 to 09-DEC-14 11:00:00 (PST-8)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet