California, 2019

Dense Fog in California, December 9 to 10, 2019

December 9 to 10, 2019 · NWS HNX · 10 events in 10 counties and zones

High pressure continued to strengthen over the area on December 10 resulting in the redevelopment of fog in the San Joaquin Valley during the early morning hours with several locations reporting visibility below a quarter of a mile. The fog resulted in several school districts in the valley either opening late or delaying bus service, and traffic being paced by law enforcement on some expressways.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
10

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.

High pressure continued to strengthen over the area on December 10 resulting in the redevelopment of fog in the San Joaquin Valley during the early morning hours with several locations reporting visibility below a quarter of a mile. The fog resulted in several school districts in the valley either opening late or delaying bus service, and traffic being paced by law enforcement on some expressways. The fog lifted into a low stratus deck by late morning with noticeable improvement in visibility taking place.

Event by event

10 dense fog. Local standard time, as filed.

Dense Fog, Foggy Bottom

When
December 9, 11:45 PM PST to December 10, 9:30 AM PST
Where
Foggy Bottom forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Hanford. Several school districts had delayed openings or delayed bus service due to fog. California Highway Patrol was pacing traffic on SR 198 between 10th Ave. and 18th Ave. due to low visibility.

Dense Fog, Fresno

When
December 9, 11:55 PM PST to December 10, 10:15 AM PST
Where
Fresno forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Fresno and Reedley. Several school districts had delayed openings or delayed bus service due to fog.

Dense Fog, Eastern Kern County

When
December 10, 2:15 AM PST to 9:15 AM PST
Where
Eastern Kern County forecast zone
Reported by
AWOS

Visibility below a quarter mile was reported in Delano. California Highway Patrol reported visibility between 600 and 1000 feet between Delano and Famoso on SR 99.

Dense Fog, Tulare County

When
December 10, 2:25 AM PST to 9:00 AM PST
Where
Tulare County forecast zone
Reported by
AWOS

Visibility below a quarter mile was reported in Visalia and Porterville. Several school districts had delayed openings or delayed bus service due to fog. California Highway Patrol was pacing traffic on SR 99 between Tipton and Delano due to low visibility.

Dense Fog, Bakersfield

When
December 10, 2:25 AM PST to 9:00 AM PST
Where
Bakersfield forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Bakersfield. California Highway Patrol reported visibility between 500 and 600 feet in south Bakersfield.

Dense Fog, Western San Joaquin Valley

When
December 10, 3:48 AM PST to 10:13 AM PST
Where
Western San Joaquin Valley forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Lemoore. Several school districts had delayed openings or delayed bus service due to fog.

Dense Fog, Southern Kings County

When
December 10, 5:00 AM PST to 9:00 AM PST
Where
Southern Kings County forecast zone
Reported by
Broadcast Media

Several school districts had delayed openings or delayed bus service due to fog.

Dense Fog, Western Kern County

When
December 10, 5:00 AM PST to 9:00 AM PST
Where
Western Kern County forecast zone
Reported by
Broadcast Media

Several school districts had delayed openings or delayed bus service due to fog.

Dense Fog, Merced and Madera

When
December 10, 6:30 AM PST to 11:00 AM PST
Where
Merced and Madera forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Merced and Madera. Several school districts had delayed openings or delayed bus service due to fog.

Dense Fog, San Joaquin Confluence

When
December 10, 6:30 AM PST to 10:00 AM PST
Where
San Joaquin Confluence forecast zone
Reported by
Broadcast Media

Several school districts had delayed openings or delayed bus service due to fog.

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 2019Every state in 2019This day in weather historyWarnings in California, December 2019

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: 859925, 859926, 859931, 859928, 859932, 859923, 859929, 859930, 859920, 859922.