California, 2018

Dense Fog in California, December 8 to 9, 2018

December 8 to 9, 2018 · NWS HNX · 4 events in 3 counties and zones

High pressure strengthened over the area on December 8. With winds remaining light in the San Joaquin Valley and skies having cleared out the previous afternoon.

The toll

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

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 strengthened over the area on December 8. With winds remaining light in the San Joaquin Valley and skies having cleared out the previous afternoon. Widespread dense fog developed in the San Joaquin Valley during the early morning hours impacting travel along several of the major highways in the valley. While the fog lifted into a low clouds deck across most the the valley, the dense fog persisted in the Merced and Atwater areas into the afternoon and reformed during the evening. Visibility finally improved during the early morning of December 9 as the fog lifted into a low cloud deck.

Event by event

4 dense fog. Local standard time, as filed.

Dense Fog, Se S.J. Valley

When
December 8, 1:40 AM PST to 9:56 AM PST
Where
Se S.J. Valley forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Visalia, Porterville and Bakersfield.

Dense Fog, E Central S.J. Valley

When
December 8, 4:15 AM PST to 12:25 PM PST
Where
E Central S.J. Valley forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Fresno, Madera, Merced and Atwater.

Dense Fog, Sw S.J. Valley

When
December 8, 4:30 AM PST to 7:53 AM PST
Where
Sw S.J. Valley forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Hanford.

Dense Fog, E Central S.J. Valley

When
December 8, 3:55 PM PST to December 9, 12:55 AM PST
Where
E Central S.J. Valley forecast zone
Reported by
ASOS

Visibility below a quarter mile was reported in Merced and Atwater.

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 2018Every state in 2018This day in weather historyWarnings in California, December 2018

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: 788651, 788647, 788648, 788652.