California, 2021Dense Fog in California, December 2, 2021
December 2, 2021 · NWS STO · 1 event in 1 county or zone
On the morning of December 2nd dense fog developed over the southern Sacramento Valley and northern San Joaquin Valleys. Observation sites within in the area generally reported dense fog with visibility at or less than a quarter of a mile.
- Deaths
- 1
- Injuries
- 3
- 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.
On the morning of December 2nd dense fog developed over the southern Sacramento Valley and northern San Joaquin Valleys. Observation sites within in the area generally reported dense fog with visibility at or less than a quarter of a mile.
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 Sacramento, CA wrote its last area forecast discussion before the first event at Dec 2, 1:42 AM PST, 23 minutes earlier.
Area forecast discussion, Dec 2, 1:42 AM PST, 23 minutes before
Area Forecast Discussion
National Weather Service Sacramento CA
142 AM PST Thu Dec 2 2021
.SYNOPSIS...
Mainly dry weather still...but a weaker weather system will bring
light showers to the area Monday into Monday night. A breezy day
behind it on Tuesday.
&&
.DISCUSSION...
High pressure will remain over California through the weekend.
Temperatures will continue to be well above normal for this time
of year with patches of fog developing each night near the central
part of the valley and near water ways. This morning looks like
the fog will be dense again for spots that where dense yesterday
morning over the southern Sacramento valley, northern San Joaquin
valley and Delta especially when you get near I-5 and traveling
west into the Delta. Little change is expected through the rest of
the week.
&&
.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
A weak trough will bring some cooling to the region Monday into
early Tuesday as it passes through along with the chance of some
light precipitation. Precipitation chances continue to be mainly
over the northern end of the valley and over the mountains at this
time. A ridge of high pressure returns after the passage of the
trough along with some northerly winds for the valley. Another
weak system will move into the region next Thursday and may bring
a better chance of precipitation to the entire region than the one
earlier in the week.
&&
.AVIATION...
VFR conditions predominate except for areas of MVFR with local
IFR/LIFR conditions (BR/FG) in the Central Valley south of KCIC
until about 20Z. Surface wind gusts generally below 10 kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM PST this morning for Carquinez
Strait and Delta-Central Sacramento Valley-Northern San Joaquin
Valley-Southern Sacramento Valley.
&&
Dense Fog, Southern Sacramento Valley
- When
- December 2, 2:05 AM PST to 10:00 AM PST
- Where
- Southern Sacramento Valley forecast zone
- Deaths
- 0 direct, 1 indirect
- Injuries
- 0 direct, 3 indirect
- Reported by
- Department of Highways
A 3 vehicle accident occurred around 4am on eastbound I-80 at Richard Blvd near Davis, CA. 1 fatality and 3 injuries reported. Eastbound lanes were closed for approximately 4 hours. Dense fog was in the area at the time and is speculated to be cause but still to be determined. Nearby visibility observations were around 0.1 mile.
- 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.
- Dense Fog in Texas, December 2, 20219 injured · $195,000 · 1 event
- Damaging Winds and Strong Wind in New York, December 2 to 3, 2021$12,000 · 9 events
- Marine Thunderstorm Winds in North Atlantic Coastal Waters, December 2, 20218 events
- Marine High Wind in Lake Superior, December 2, 20213 events
- Dense Fog in California, December 2 to 6, 20213 events
- Heavy Snow in Alaska, December 2 to 3, 20212 events
- Strong Wind in West Virginia, December 2, 20211 event
- Blizzard in Alaska, December 2 to 3, 20211 event
- Dense Fog in California, December 2, 20211 event
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 2026-09-24. Each event’s entry at NCEI: 998055.