California, 2001

Dense Fog in California, December 3, 2001

December 3, 2001 · NWS SGX · 2 events in 2 counties and zones

Dense fog with visibility less than 10 feet was reported along the south slopes of the San Bernardino Mountains from the Cajon Pass to Running Springs, and along the south and west slopes of the Laguna Mountains.

Where it happened

Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

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 SGX wrote it up.

Dense fog with visibility less than 10 feet was reported along the south slopes of the San Bernardino Mountains from the Cajon Pass to Running Springs, and along the south and west slopes of the Laguna Mountains.

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 San Diego, CA wrote its last area forecast discussion before the first event at Dec 2, 9:30 PM PST, 3 hours 29 minutes earlier.

Area forecast discussion, Dec 2, 9:30 PM PST, 3 hours 29 minutes before
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In the hours before

Special weather statement, Dec 2, 10:00 PM PST, 2 hours 59 minutes before
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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 dense fog. Local standard time, as filed.

Dense Fog, P Sw San Bernardino

When
December 3, 12:59 AM PST to 6:56 AM PST
Where
P Sw San Bernardino forecast zone
Reported by
LAW ENFORCEMENT
Coordinates
34.841, -116.178 (the zone’s center; the record gives no point)

Dense Fog, San Diego T X W

When
December 3, 6:22 AM PST to 8:58 AM PST
Where
San Diego T X W forecast zone
Reported by
TRAINED SPOTTER
Coordinates
33.028, -116.770 (the zone’s center; the record gives no point)

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 2001Every state in 2001This day in weather historyWarnings in California, December 2001

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 2026-09-24. Each event’s entry at NCEI: 5274829, 5274830.