Widespread light to moderate rain (over two inches in places) over a two day period (December 4-5) was followed by a large area of high pressure. This created inversions that lead to the widespread development of fog and often dense fog.  The time of dense fog development and dissipation was difficult to forecast and record. The entire Grand Canyon was filled with low clouds at times while the Grand Canyon Airport 7 miles away was clear. Some ASOS locations were under low clouds while fog impacted highways and freeways just a few miles away.

Dense Fog in GRAND CANYON COUNTRY, ARIZONA
From 04-DEC-14 21:00:00 to 05-DEC-14 02:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS at the Grand Canyon Airport reported dense fog between 900 PM and 200 AM.

Dense Fog in WHITE MOUNTAINS, ARIZONA
From 07-DEC-14 04:30:00 to 08-DEC-14 11:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Show Low Airport reported dense fog between 400 AM and 1100 AM on the 7th and again from 700 PM on the 7th to 1100 AM on the 8th.

Dense Fog in WESTERN MOGOLLON RIM, ARIZONA
From 06-DEC-14 20:30:00 to 07-DEC-14 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Dense fog was reported at the Flagstaff Airport from about 830 PM to Midnight. Ice fog was reported around midnight as well.

Dense Fog in LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY, ARIZONA
From 07-DEC-14 20:30:00 to 08-DEC-14 02:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The St Johns Airport reported dense fog from around 830 PM on the 7th to around 200 AM on the 8th.

Dense Fog in CHUSKA MOUNTAINS AND DEFIANCE PLATEAU, ARIZONA
From 07-DEC-14 19:00:00 to 08-DEC-14 00:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Dense fog was reported along Highway 264.

Dense Fog in BLACK MESA AREA, ARIZONA
From 09-DEC-14 01:00:00 to 09-DEC-14 05:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Local police reported 1/4 mile visibility in fog in the community of Rough Rock.

Dense Fog in LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY, ARIZONA
From 06-DEC-14 05:30:00 to 06-DEC-14 06:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Winslow Airport ASOS reported dense fog between 530 and 630 AM.

Dense Fog in LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY, ARIZONA
From 05-DEC-14 04:30:00 to 05-DEC-14 09:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The ASOS at the Winslow Airport reported fog between 1/4 and 1/2 mile from around 430 AM to 9 AM.

Dense Fog in LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY, ARIZONA
From 07-DEC-14 19:30:00 to 07-DEC-14 21:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The Winslow ASOS reported dense fog between 730 PM and 1030 PM.

Dense Fog in WESTERN MOGOLLON RIM, ARIZONA
From 09-DEC-14 03:00:00 to 09-DEC-14 22:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Fog dropped the visibility at the Flagstaff Airport down to 1/4 mile at times.  Most notably in the morning and then again in the evening.

Dense Fog in WHITE MOUNTAINS, ARIZONA
From 09-DEC-14 00:00:00 to 09-DEC-14 09:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

The visibility dropped to 1/4 mile in fog at the Show Low Airport between midnight and 900 AM.