Arizona, 2011

Dense Fog in Arizona, December 14, 2011

December 14, 2011 · NWS PSR · 1 event in 1 county or zone

Clearing skies and wet grounds in the wake of a departing Pacific low pressure system led to the development of dense fog across the western Arizona deserts during the morning hours on December 15th. Many locations along the lower Colorado river valley and across the southwest Arizona deserts observed dense fog which lowered visibilities to near zero miles, beginning during the early morning…

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS PSR wrote it up.

Clearing skies and wet grounds in the wake of a departing Pacific low pressure system led to the development of dense fog across the western Arizona deserts during the morning hours on December 15th. Many locations along the lower Colorado river valley and across the southwest Arizona deserts observed dense fog which lowered visibilities to near zero miles, beginning during the early morning hours. By noon, the fog had mostly dissipated.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before the first event at Dec 13, 9:00 PM MST, 6 hours 30 minutes earlier.

Area forecast discussion, Dec 13, 9:00 PM MST, 6 hours 30 minutes before
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Hazardous weather outlook, Dec 13, 3:52 PM MST, 11 hours 38 minutes before
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Event by event

1 dense fog. Local standard time, as filed.

Dense Fog, Southwest Deserts

When
December 14, 3:30 AM MST to 12:30 PM MST
Where
Southwest Deserts forecast zone
Reported by
Trained Spotter

Clearing skies and wet ground in the wake of a departing Pacific low pressure system led to the development of widespread dense fog over the western Arizona deserts during the morning hours on December 14th. A number of trained weather spotters reported dense fog with visibility at or below one quarter mile. A spotter one mile west of Tacna reported dense fog with visibility down to 100 yards at 954 am. Dense fog was also reported by the Parker Sheriff's Office; they indicated that dense fog in Vicksburg Junction lowered visibility below 10 feet at 330 am. Fortunately, no significant accidents or injuries were reported due to the low visibilities and potentially dangerous driving conditions.

What these are

Dense Fog
Fog reducing visibility to a quarter mile or less, filed where it caused accidents or disruption.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Arizona in 2011Every state in 2011This day in weather historyWarnings in Arizona, December 2011

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-30. Each event’s entry at NCEI: 353250.