California, 2015

Dense Fog in California, January 11 to 16, 2015

January 11 to 16, 2015 · NWS HNX · 21 events in 6 counties and zones

Plenty of low level moisture and stable conditions under high pressure allowed dense fog to form each night and morning from January 11 to 16, 2015. In the days prior to this, there had been patchy fog, but it became more widespread throughout the San Joaquin Valley after a weak weather disturbance brought rain across Kern county on the January 10-11.

The toll

Deaths
0
Injuries
4
Property damage
None recorded
Crop damage
None recorded
Events
21

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 HNX wrote it up.

Plenty of low level moisture and stable conditions under high pressure allowed dense fog to form each night and morning from January 11 to 16, 2015. In the days prior to this, there had been patchy fog, but it became more widespread throughout the San Joaquin Valley after a weak weather disturbance brought rain across Kern county on the January 10-11.

The dense fog formed in Kings and Tulare counties in the evening of January 11, then spread into Fresno, Madera, and Merced counties as well as south into Kern county by early morning on January 12. Visibilities dropped to less than 500 feet in many areas. The fog lifted in most areas by noon on January 12. Dense fog also developed on parts of the Kern county desert areas near Edwards AFB and Ridgecrest.

The fog quickly redeveloped in the early evening of January 12 and continue through the morning of January 13 with widespread visibilities below 1/4 mile and many areas reporting visibility below 800 feet. The fog cleared between 10 AM and noon.

The worst of the fog occurred on January 14, with dense fog developing around midnight, but not clearing until nearly 2 pm. There were numerous school bus delays due to the dense fog and California Highway Patrol was pacing traffic on area highways. A major traffic accident occurred in Visalia involving three vehicles and resulting in major injuries to two people.

The dense fog redeveloped on the evening of January 14 and continue through noon on January 15. It then quickly redeveloped early evening on the 15th, but lifted above 1/4 mile by 3 am on the 16th as a weak disturbance moving by to the north helped to lift the fog into a stratus deck.

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 Hanford, CA wrote its last area forecast discussion before the first event at Jan 11, 3:51 PM PST, 3 hours 24 minutes earlier.

Area forecast discussion, Jan 11, 3:51 PM PST, 3 hours 24 minutes before
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Event by event

21 dense fog. Local standard time, as filed.

Dense Fog, Se S.J. Valley

When
January 11, 7:15 PM PST to January 12, 12:00 PM PST
Where
Se S.J. Valley forecast zone
Reported by
Mesonet

Visibility less than 100 feet in Bakersfield.

Dense Fog, Indian Wells Vly

When
January 11, 9:45 PM PST to January 12, 9:00 AM PST
Where
Indian Wells Vly forecast zone
Reported by
Public

Visibility less than 300 feet on US395 in Ridgecrest.

Dense Fog, Sw S.J. Valley

When
January 11, 10:00 PM PST to January 12, 12:00 PM PST
Where
Sw S.J. Valley forecast zone
Reported by
Mesonet

Dense Fog, E Central S.J. Valley

When
January 12, 2:45 AM PST to 12:00 PM PST
Where
E Central S.J. Valley forecast zone
Reported by
Mesonet

Dense Fog, W Central S.J. Valley

When
January 12, 6:00 AM PST to 12:00 PM PST
Where
W Central S.J. Valley forecast zone
Reported by
Mesonet

Dense Fog, Se Kern Cty Desert

When
January 12, 6:52 AM PST to 9:09 AM PST
Where
Se Kern Cty Desert forecast zone
Reported by
Mesonet

Visibility 1/8 mile at Edward AFB.

Dense Fog, Se S.J. Valley

When
January 12, 6:12 PM PST to January 13, 10:00 AM PST
Where
Se S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 800 feet.

Dense Fog, Indian Wells Vly

When
January 12, 6:20 PM PST to January 13, 8:00 AM PST
Where
Indian Wells Vly forecast zone
Reported by
Trained Spotter

Patchy fog with visibility near 100 feet in Ridgecrest.

Dense Fog, Sw S.J. Valley

When
January 12, 6:43 PM PST to January 13, 10:00 AM PST
Where
Sw S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet.

Dense Fog, W Central S.J. Valley

When
January 12, 6:45 PM PST to January 13, 10:00 AM PST
Where
W Central S.J. Valley forecast zone
Reported by
Mesonet

Dense Fog, E Central S.J. Valley

When
January 12, 6:45 PM PST to January 13, 12:00 PM PST
Where
E Central S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet.

Dense Fog, Sw S.J. Valley

When
January 13, 11:30 PM PST to January 14, 1:00 PM PST
Where
Sw S.J. Valley forecast zone
Injuries
0 direct, 2 indirect
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet. CHP pacing on State Route 43.

Dense Fog, Se S.J. Valley

When
January 13, 11:30 PM PST to January 14, 1:30 PM PST
Where
Se S.J. Valley forecast zone
Injuries
0 direct, 2 indirect
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet.

Dense Fog, W Central S.J. Valley

When
January 14, 12:00 AM PST to 12:15 PM PST
Where
W Central S.J. Valley forecast zone
Reported by
Law Enforcement

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet. CHP pacing on State Route 41.

Dense Fog, E Central S.J. Valley

When
January 14, 12:00 AM PST to 12:15 PM PST
Where
E Central S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet. Fresno Airport visibility less than 1/16 mile resulting in flight delays.

Dense Fog, E Central S.J. Valley

When
January 14, 6:15 PM PST to January 15, 11:00 AM PST
Where
E Central S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet. CHP pacing traffic on much of Highway 99.

Dense Fog, Sw S.J. Valley

When
January 14, 7:50 PM PST to January 15, 12:00 PM PST
Where
Sw S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet. Visibility at KNLC reported near zero.

Dense Fog, Se S.J. Valley

When
January 14, 7:50 PM PST to January 15, 12:00 PM PST
Where
Se S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet.

Dense Fog, W Central S.J. Valley

When
January 14, 8:00 PM PST to January 15, 11:00 AM PST
Where
W Central S.J. Valley forecast zone
Reported by
Mesonet

Widespread visibility less than 1/4 mile with areas of visibility less than 500 feet. CHP pacing on Interstate 5 in Merced and Fresno counties.

Dense Fog, E Central S.J. Valley

When
January 15, 4:00 PM PST to January 16, 3:04 AM PST
Where
E Central S.J. Valley forecast zone
Reported by
Mesonet

Dense Fog, Sw S.J. Valley

When
January 15, 4:00 PM PST to January 16, 3:04 AM PST
Where
Sw S.J. Valley forecast zone
Reported by
Mesonet

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 California in 2015Every state in 2015This day in weather historyWarnings in California, January 2015

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 2026-10-01. Each event’s entry at NCEI: 551382, 551383, 551381, 551380, 551379, 551384, 551388, 551389, 551387, 551385, 551386, 551392, 551393, 551390, 551391, 551395, 551396, 551397, 551394, 551398, 551399.