An upper level system with a strong cold front moved through the Bay Area at the turn of the month with precipitation beginning late the evening of the 28th. This system brought widespread rainfall causing localized roadway flooding, strong winds, lightning, and small hail. Gusts in the mountains reached 60 mph and hail was seen up to 1/2 an inch. The bulk of the precipitation and subsequent impacts were seen in early March.

Strong Wind in SAN FRANCISCO, CALIFORNIA
From 01-MAR-18 09:16:00 to 01-MAR-18 09:31:00 (PST-8)
Magnitude: 40.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

News report states roughly 1200 customers around the Bay Area are without power.

Flood in SANTA CLARA, CALIFORNIA
From 01-MAR-18 04:49:00 to 01-MAR-18 05:19:00 (PST-8)
Location: (SJC)SAN JOSE INTL A
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding at 2020 Junction Ave.

Flood in SONOMA, CALIFORNIA
From 01-MAR-18 09:09:00 to 01-MAR-18 09:39:00 (PST-8)
Location: SCHELLVILLE ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at SR 121 and Sears Point Dr.

Flood in MARIN, CALIFORNIA
From 01-MAR-18 09:31:00 to 01-MAR-18 10:01:00 (PST-8)
Location: CORTE MADERA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at 250 BonAir Road.

Flood in CONTRA COSTA, CALIFORNIA
From 01-MAR-18 09:55:00 to 01-MAR-18 10:25:00 (PST-8)
Location: SELBY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding at I80 E and Pomona Street on ramp.

Flood in MARIN, CALIFORNIA
From 01-MAR-18 02:26:00 to 01-MAR-18 02:56:00 (PST-8)
Location: GREEN BRAE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at US 101N and Lucky Drive off ramp.

Flood in SAN MATEO, CALIFORNIA
From 01-MAR-18 10:25:00 to 01-MAR-18 10:55:00 (PST-8)
Location: STERLING PARK
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at I 280N and SR 1.

Flood in CONTRA COSTA, CALIFORNIA
From 01-MAR-18 10:38:00 to 01-MAR-18 11:08:00 (PST-8)
Location: VINEHILL
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at Pacheco Blvd and Arthur Road.

Flood in SAN MATEO, CALIFORNIA
From 01-MAR-18 10:50:00 to 01-MAR-18 11:20:00 (PST-8)
Location: BAYSHORE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at US 101S and Oyster Point east off ramp.

Flood in SAN MATEO, CALIFORNIA
From 01-MAR-18 10:56:00 to 01-MAR-18 11:26:00 (PST-8)
Location: BADEN
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at I 280S and Hickey Blvd off ramp.

Flood in SANTA CLARA, CALIFORNIA
From 01-MAR-18 11:38:00 to 01-MAR-18 12:08:00 (PST-8)
Location: MILPITAS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding at I 680N and Scott Creek Road off ramp.

Flood in SAN FRANCISCO, CALIFORNIA
From 01-MAR-18 10:19:00 to 01-MAR-18 10:49:00 (PST-8)
Location: OCEAN VIEW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at I 280N and Cesar Chavez Street off ramp.

Flood in SANTA CLARA, CALIFORNIA
From 01-MAR-18 10:24:00 to 01-MAR-18 10:54:00 (PST-8)
Location: RANCHO RINCONADO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at I 280N and Stevens Creek Blvd on ramp.

Flood in MONTEREY, CALIFORNIA
From 01-MAR-18 13:30:00 to 01-MAR-18 14:00:00 (PST-8)
Location: SPRECKELS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at S Davis Road and Foster Road.

Flood in SAN FRANCISCO, CALIFORNIA
From 02-MAR-18 01:48:00 to 02-MAR-18 02:28:00 (PST-8)
Location: SAN FRANCISCO
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at 455 8th Street.

Flood in MARIN, CALIFORNIA
From 02-MAR-18 11:24:00 to 02-MAR-18 11:54:00 (PST-8)
Location: MARIN CITY
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Roadway flooding reported at Almonte Blvd and SR 1.

Strong Wind in COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE, CALIFORNIA
From 01-MAR-18 09:26:00 to 01-MAR-18 09:30:00 (PST-8)
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong Wind in SOUTHERN MONTEREY BAY AND BIG SUR COAST, CALIFORNIA
From 01-MAR-18 12:45:00 to 01-MAR-18 13:00:00 (PST-8)
Magnitude: 40.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Downed tree reported at Montecito Drive and English. Exact timing unknown.

Strong Wind in COASTAL NORTH BAY INCLUDING POINT REYES NATIONAL SEASHORE, CALIFORNIA
From 01-MAR-18 18:26:00 to 01-MAR-18 18:41:00 (PST-8)
Magnitude: 41.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotter reported 47 mph wind gusts at the docks.

Strong Wind in EAST BAY INTERIOR VALLEYS, CALIFORNIA
From 01-MAR-18 20:25:00 to 01-MAR-18 20:40:00 (PST-8)
Magnitude: 40.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Tree down on Crest Ave.

Hail in ALAMEDA, CALIFORNIA
From 02-MAR-18 07:25:00 to 02-MAR-18 07:30:00 (PST-8)
Location: OAKLAND
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Several reports of pea-sized hail in Oakland via social media.

Hail in MARIN, CALIFORNIA
From 02-MAR-18 08:17:00 to 02-MAR-18 08:22:00 (PST-8)
Location: BOLINAS
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in ALAMEDA, CALIFORNIA
From 02-MAR-18 08:40:00 to 02-MAR-18 08:45:00 (PST-8)
Location: BERKELEY
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Pea-sized hail reported in north Berkeley via social media.

Hail in SANTA CRUZ, CALIFORNIA
From 02-MAR-18 09:44:00 to 02-MAR-18 09:49:00 (PST-8)
Location: FELTON
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Small hail reported in Felton.

Lightning in SAN FRANCISCO, CALIFORNIA
From 02-MAR-18 09:46:00 to 02-MAR-18 09:50:00 (PST-8)
Location: CRISSY AAF
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Lightning detected over the San Francisco Bay.

Hail in SANTA CRUZ, CALIFORNIA
From 02-MAR-18 09:48:00 to 02-MAR-18 09:53:00 (PST-8)
Location: SCOTTS VLY
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Pea-sized hail reported in Scotts Valley.

Hail in ALAMEDA, CALIFORNIA
From 02-MAR-18 10:10:00 to 02-MAR-18 10:15:00 (PST-8)
Location: BERKELEY
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Social media reports of another round of hail this morning in Berkeley.

Hail in CONTRA COSTA, CALIFORNIA
From 02-MAR-18 10:22:00 to 02-MAR-18 10:27:00 (PST-8)
Location: KENSINGTON
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Accumulating hail reported in Kensington.

Hail in CONTRA COSTA, CALIFORNIA
From 02-MAR-18 12:34:00 to 02-MAR-18 12:39:00 (PST-8)
Location: EL CERRITO
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Small hail reported.

Hail in SANTA CLARA, CALIFORNIA
From 02-MAR-18 09:43:00 to 02-MAR-18 09:48:00 (PST-8)
Location: SAN JOSE
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Small hail reprted on I-87 in San Jose.

Heavy Rain in SANTA CRUZ, CALIFORNIA
From 02-MAR-18 17:54:00 to 02-MAR-18 18:24:00 (PST-8)
Location: BEN LOMOND
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Newspaper

Heavy rain triggered a domino effect of falling trees. A redwood came down onto smaller trees and one hit a house.

Debris Flow in MONTEREY, CALIFORNIA
From 02-MAR-18 18:53:00 to 02-MAR-18 19:23:00 (PST-8)
Location: GORDA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Highway 1 closed due to mudslide at Limekiln State Park.

Hail in MONTEREY, CALIFORNIA
From 03-MAR-18 09:58:00 to 03-MAR-18 10:03:00 (PST-8)
Location: DEL REY OAKS
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

Hail in MARIN, CALIFORNIA
From 03-MAR-18 09:58:00 to 03-MAR-18 10:03:00 (PST-8)
Location: SAN RAFAEL
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Hail in MARIN, CALIFORNIA
From 03-MAR-18 10:50:00 to 03-MAR-18 10:55:00 (PST-8)
Location: MILL VLY
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CONTRA COSTA, CALIFORNIA
From 03-MAR-18 11:55:00 to 03-MAR-18 12:00:00 (PST-8)
Location: MARTINEZ
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CONTRA COSTA, CALIFORNIA
From 03-MAR-18 12:24:00 to 03-MAR-18 12:29:00 (PST-8)
Location: CONCORD
Magnitude: 0.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CONTRA COSTA, CALIFORNIA
From 03-MAR-18 13:07:00 to 03-MAR-18 13:12:00 (PST-8)
Location: LAFAYETTE
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in CONTRA COSTA, CALIFORNIA
From 03-MAR-18 13:35:00 to 03-MAR-18 13:40:00 (PST-8)
Location: DANVILLE
Magnitude: 0.25 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong Wind in EAST BAY HILLS AND THE DIABLO RANGE, CALIFORNIA
From 01-MAR-18 09:18:00 to 01-MAR-18 10:18:00 (PST-8)
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Measured wind gust of 45 mph at the Calavares Road RAWS.

Strong Wind in EAST BAY HILLS AND THE DIABLO RANGE, CALIFORNIA
From 01-MAR-18 07:28:00 to 01-MAR-18 10:28:00 (PST-8)
Magnitude: 46.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Measured wind gusts between 45 and 53 mph observed during this time frame at Las Trampas RAWS.

High Wind in SANTA CRUZ MOUNTAINS, CALIFORNIA
From 01-MAR-18 03:32:00 to 01-MAR-18 10:32:00 (PST-8)
Magnitude: 53.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Measured wind gusts of at least 50 mph and peaking at 61 mph at Los Gatos RAWS.

Strong Wind in EAST BAY HILLS AND THE DIABLO RANGE, CALIFORNIA
From 01-MAR-18 10:45:00 to 01-MAR-18 11:45:00 (PST-8)
Magnitude: 43.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Sustained southerly winds of 35 mph gusting to 50 mph was observed at the Los Vaqueros RAWS.

Strong Wind in NORTH BAY MOUNTAINS, CALIFORNIA
From 01-MAR-18 08:51:00 to 01-MAR-18 09:51:00 (PST-8)
Magnitude: 40.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Wind gusts of 46 mph observed at Woodacre RAWS.

Strong Wind in SAN FRANCISCO PENINSULA COAST, CALIFORNIA
From 01-MAR-18 10:18:00 to 01-MAR-18 12:18:00 (PST-8)
Magnitude: 40.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Measured wind gusts over 45 mph observed at Spring Valley RAWS.

Strong Wind in NORTH BAY MOUNTAINS, CALIFORNIA
From 01-MAR-18 02:29:00 to 01-MAR-18 12:29:00 (PST-8)
Magnitude: 43.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Sustained winds around 30 mph gusting to between 45 and 49 mph were observed during this time period at Atlas Peak RAWS.