Flash Flooding in California, February 2 to 9, 1998

Name: Flash Flooding in California, February 2 to 9, 1998
Start: 1998-02-02T10:00
End: 1998-02-09T08:28
Location: California

February 2 to 9, 1998 · NWS MTR · 36 events in 11 counties and zones

Levee Breached along Arroyo Mocha (a dry Creek) and caused damage to roads and property

Where it happened

Every event with a place to put it; 36 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 1
Injuries: 1
Property damage: $3.6 million
Crop damage: $159,000
Events: 36

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 MTR wrote it up.

Levee Breached along Arroyo Mocha (a dry Creek) and caused damage to roads and property

The radar

The San Francisco radar (KMUX), 51 km away, was scanning. The volume nearest the first event began at 17:59 UTC.

Open the radar archive at this moment

Event by event

36 flash flood. Local standard time, as filed.

Flash Flood, San Mateo

When: February 2, 10:00 AM PST to February 3, 2:45 AM PST
Where: San Mateo County, Pescadero
Property damage: $200,000
Coordinates: 37.436, -122.356 (the zone’s center; the record gives no point)

Flash Flood, Santa Cruz

When: February 2, 11:00 AM PST to February 3, 7:10 AM PST
Where: Santa Cruz County, Felton
Deaths: 1 direct, 0 indirect
Property damage: $500,000
Coordinates: 37.022, -122.010 (the zone’s center; the record gives no point)

Flash flood po San Lorenzo River from Felton to Santa Cruz.

Flash Flood, Marin

When: February 2, 6:40 PM PST to February 3, 1:22 AM PST
Where: Marin County, Novato
Coordinates: 38.055, -122.749 (the zone’s center; the record gives no point)

Novato Creek

Flash Flood, Sonoma

When: February 2, 6:50 PM PST to February 3, 12:57 PM PST
Where: Sonoma County, Petaluma
Property damage: $2.0 million
Coordinates: 38.525, -122.922 (the zone’s center; the record gives no point)

Flash Flood on Willow Brook at Stoney Point Road near Petaluma. 25 homes near the river were evacuated as well as 40 to 50 residents of a Mobile home park.

Flash Flood, Alameda

When: February 2, 8:20 PM PST to February 3, 1:10 AM PST
Where: Alameda County, Hayward
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Flash flood on Castro Valley Creek.

Flash Flood, Monterey

When: February 2, 8:30 PM PST to February 4, 3:30 AM PST
Where: Monterey County, Lockwood
Coordinates: 36.240, -121.309 (the zone’s center; the record gives no point)

San Antonio River near Lockwood

Flash Flood, Napa

When: February 2, 9:40 PM PST to 9:58 PM PST
Where: Napa County, Central Portion
Coordinates: 38.507, -122.330 (the zone’s center; the record gives no point)

Flash flood on the Napa Creek on Hwy 29 near Napa.

Flash Flood, San Mateo

When: February 2, 11:00 PM PST to February 3, 3:30 AM PST
Where: San Mateo County, East Palo Alto
Coordinates: 37.436, -122.356 (the zone’s center; the record gives no point)

San Francisquito Creek

Flash Flood, Contra Costa

When: February 3, 12:00 AM PST to 3:00 PM PST
Where: Contra Costa County, Walnut Creek
Coordinates: 37.923, -121.951 (the zone’s center; the record gives no point)

people evacuated Walnut Creek due to flash Flood.

Flash Flood, Contra Costa

When: February 3, 12:00 AM PST to 12:00 PM PST
Where: Contra Costa County, Pittsburg
Coordinates: 37.923, -121.951 (the zone’s center; the record gives no point)

Hwy 4 near bailey Rd flash flooded by runoff.

Flash Flood, Santa Clara

When: February 3, 2:10 AM PST
Where: Santa Clara County, San Jose
Coordinates: 37.233, -121.696 (the zone’s center; the record gives no point)

Guadalupe River at Blossom Hill Blvd.

Flash Flood, Monterey

When: February 3, 2:30 AM PST to 3:30 AM PST
Where: Monterey County, Carmel Vly
Coordinates: 36.240, -121.309 (the zone’s center; the record gives no point)

Carmel River at Robles del Rio

Flash Flood, Alameda

When: February 3, 5:00 AM PST
Where: Alameda County, Livermore
Property damage: $250,000
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Flash Flood, Alameda

When: February 3, 6:30 AM PST
Where: Alameda County, Dublin
Property damage: $100,000
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Flash Flood, Alameda

When: February 3, 7:00 AM PST
Where: Alameda County, Niles
Property damage: $200,000
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Flash Flood, Alameda

When: February 3, 8:00 AM PST
Where: Alameda County, Sunol
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Flash Flood, Monterey

When: February 3, 8:08 AM PST to 12:05 PM PST
Where: Monterey County, South Portion
Coordinates: 36.240, -121.309 (the zone’s center; the record gives no point)

flaash flood on the the San Lorinzo creek near King City.

Flash Flood, Alameda

When: February 3, 9:00 AM PST
Where: Alameda County, Decoto
Property damage: $150,000
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Flash Flood, Sonoma

When: February 3, 9:30 AM PST
Where: Sonoma County, Sonoma
Injuries: 1 direct, 0 indirect
Property damage: $200,000
Crop damage: $159,000
Coordinates: 38.525, -122.922 (the zone’s center; the record gives no point)

Flash Flood, Sonoma

When: February 5, 6:00 PM PST to 6:20 PM PST
Where: Sonoma County, Petaluma
Coordinates: 38.525, -122.922 (the zone’s center; the record gives no point)

On Willow Brook

Flash Flood, San Mateo

When: February 6, 10:00 AM PST to 8:30 PM PST
Where: San Mateo County, East Palo Alto
Coordinates: 37.436, -122.356 (the zone’s center; the record gives no point)

San Francisquito Creek

Flash Flood, San Mateo

When: February 6, 10:20 AM PST to 9:45 PM PST
Where: San Mateo County, Pescadero
Coordinates: 37.436, -122.356 (the zone’s center; the record gives no point)

Pescadero Creek

Flash Flood, Sonoma

When: February 6, 12:22 PM PST to February 7, 12:02 AM PST
Where: Sonoma County, Petaluma
Coordinates: 38.525, -122.922 (the zone’s center; the record gives no point)

On Willow Brook

Flash Flood, San Francisco

When: February 7, 9:30 AM PST to 12:30 PM PST
Where: San Francisco County, San Francisco
Coordinates: 37.778, -122.442 (the zone’s center; the record gives no point)

Embarcadero in San Francisco Flooded due to flash flood and high tide with strong winds .

Flash Flood, Alameda

When: February 7, 11:00 AM PST to 3:00 PM PST
Where: Alameda County, Niles District
Coordinates: 37.651, -121.918 (the zone’s center; the record gives no point)

Alameda Creek

Flash Flood, Marin

When: February 7, 11:30 AM PST to 3:20 PM PST
Where: Marin County, Novato
Coordinates: 38.055, -122.749 (the zone’s center; the record gives no point)

Flash Flood, Sonoma

When: February 7, 1:18 PM PST to 8:00 PM PST
Where: Sonoma County, Petaluma
Coordinates: 38.525, -122.922 (the zone’s center; the record gives no point)

On Willow Brook

Flash Flood, Santa Clara

When: February 7, 1:50 PM PST to 2:30 PM PST
Where: Santa Clara County, San Jose
Coordinates: 37.233, -121.696 (the zone’s center; the record gives no point)

Ross Creek at Cherry street.

Flash Flood, San Mateo

When: February 7, 2:00 PM PST to 8:00 PM PST
Where: San Mateo County, East Palo Alto
Coordinates: 37.436, -122.356 (the zone’s center; the record gives no point)

San Francisquito Creek

Flash Flood, San Mateo

When: February 7, 2:50 PM PST to 8:40 PM PST
Where: San Mateo County, Pescadero
Coordinates: 37.436, -122.356 (the zone’s center; the record gives no point)

Pescadero Creek

Flash Flood, Santa Cruz

When: February 7, 2:52 PM PST to 5:50 PM PST
Where: Santa Cruz County, Felton
Coordinates: 37.022, -122.010 (the zone’s center; the record gives no point)

San Lorenzo at Felton

Flash Flood, Monterey

When: February 7, 3:00 PM PST to February 8, 4:30 PM PST
Where: Monterey County, Lockwood
Coordinates: 36.240, -121.309 (the zone’s center; the record gives no point)

San Antoio River near Lockwood

Flash Flood, San Benito

When: February 7, 3:45 PM PST to 7:00 PM PST
Where: San Benito County, Central Portion
Coordinates: 36.606, -121.075 (the zone’s center; the record gives no point)

San Benito River at near Willow Creek School

Flash Flood, Monterey

When: February 7, 4:05 PM PST to 7:30 PM PST
Where: Monterey County, King City Arpt
Coordinates: 36.240, -121.309 (the zone’s center; the record gives no point)

San Lorinzo Creek near King City

Flash Flood, Monterey

When: February 7, 4:30 PM PST to 6:15 PM PST
Where: Monterey County, Carmel Vly
Coordinates: 36.240, -121.309 (the zone’s center; the record gives no point)

Carmel River at Robles Del Rio

Flash Flood, Santa Clara

When: February 8, 2:00 PM PST to February 9, 8:28 AM PST
Where: Santa Clara County, San Jose
Coordinates: 37.233, -121.696 (the zone’s center; the record gives no point)

Coyote Creek at Edenvale

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Flash Flood, Santa Cruz	1998-02-03	62	Male	In Water	Direct

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 1998 Every state in 1998 This day in weather history Warnings in California, February 1998

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: 5636771, 5636772, 5636913, 5636779, 5636776, 5636926, 5636778, 5636918, 5636932, 5636933, 5636921, 5636929, 5636775, 5636768, 5636769, 5636770, 5636777, 5636773, 5636774, 5636780, 5636919, 5636916, 5636781, 5636931, 5636915, 5636914, 5636912, 5636922, 5636920, 5636917, 5636924, 5636927, 5636925, 5636928, 5636930, 5636923.