USA – Over 520mm of Rain in 48 Hours, Evacuations as Rivers Rise in Northern California

by in News, USA

Heavy rain brought by an atmospheric river caused river levels to increase dramatically in Northern California from 26 February, 2019.

Russian River at Guerneville, California, is predicted to reach 46 feet later today. Evacuations orders have been issued. Photo: Sonoma County Sheriff’s Office

NWS Bay Area said that Venado in Sonoma County has recorded “an incredible 20.48 inches” (520.19 mm) of rain in 48 hours to 27 February, 2019.

NWS forecast that the Russian River at Guerneville in Sonoma County would reach 46 feet by Wednesday 27 February, which is 14 feet above its flood stage. The Russian River’s record flood level is 49.5 feet set in February 1986.

Mandatory evacuation orders were issued on 26 February for thousands of people living in over 20 communities along the river. Some schools and roads have been closed and there is a high risk of mudslides according to County of Sonoma Emergency.

Sonoma County Sheriff’s Office said via Social Media that “Guerneville is land locked. You cannot get into or out of town. All roads leading to the community are flooded.”

The communities under evacuation orders are: Asti, Bailhache, Chianti, Guerneville, Guernewood, Guernewood Park, Hacienda, Jenner, Jimtown, Korbel, Lytton, Northwood, Northwood Lodge, Rolands, Sheridan, Duncans Mills, El Bonita, Mirabel Heights, Mirabel Park, Monte Rio, Montesano, Summerhome Park, Vacation Beach and Wilson Grove. An interactive flood map of the area is available here.

Levels of the Napa River near Napa and near St Helena were also rising and by 27 February had reached moderate flood stage.

Levels of the Russian River at Guerneville. Image: NWS

Social Media

Flood Summary

Last updated: March 8, 2019
Event
California, February to March 2019
Date
February 26, 2019
Type
River flood
Cause
Extreme rainfall
Heavy rain brought by an atmospheric river, caused rivers to overflow in Northern California from 26 February, 2019. NWS forecast the Russian River at Guerneville in Sonoma County would reach 46 feet by Wednesday 27 February, which is 14 feet above its flood stage. Mandatory evacuation orders were issued on 26 February for thousands of people living in over 20 communities along the river. Roads have been closed and there is a high risk of mudslides The evacuated communities are: Asti, Bailhache, Chianti, Guerneville, Guernewood, Guernewood Park, Hacienda, Jenner, Jimtown, Korbel, Lytton, Northwood, Northwood Lodge, Rolands, Sheridan, Duncans Mills, El Bonita, Mirabel Heights, Mirabel Park, Monte Rio, Montesano, Summerhome Park, Vacation Beach and Wilson Grove. As of 28 February, Associated Press reported that around 2,000 homes had been inundated in the Guerneville area. Another Pacific storm brought more severe weather and heavy rains to California from 06 March, 2019. Severe flooding was reported in Sonora. NWS Sacramento said that 0.92 inches / 23.37 mm of rain fell in 1 hour in Sonora on 06 March, 2019.

Locations

A - Sonoma County
B - Butte County
C - Fernbridge, Loleta, Humboldt County
D - Sonora
E - Russian River at Guerneville - River level 13.83 metres
F - Venado - Rainfall level 520.19 mm in 48 hours
G - Santa Rosa - Rainfall level 141.22 mm in 24 hours
H - Eel River at Fernbridge - River level 7.82 metres

Magnitude

River level
13.83 metres
Russian River at Guerneville - February 27 to February 27, 2019
On 27 February jumped from 38.74 feet and crested at 45.38 feet (13.83 metres) . Major flood stage is 40 feet. Record is 49.5 feet.
Rainfall level
520.19 mm in 48 hours
Venado - February 25 to February 27, 2019
NWS Bay Area figures (only available for 48 hour period)
Rainfall level
141.22 mm in 24 hours
Santa Rosa - February 26 to February 26, 2019
NWS Bay Area said this is the wettest day on record for Santa Rosa.
River level
7.82 metres
Eel River at Fernbridge - February 27 to February 27, 2019
Eel River at Fernbridge crested at 25.67 feet on 27 February, the fifth highest crest on record. Major flood stage for that point in the river is 25 feet.

Damages

Evacuated
3,500
Sonoma County - February 26, 2019
Estimated figure: Authorities issued a mandatory evacuation notice for over 20 communities. As of 27 February, exact numbers of evacuees were not available and some reports suggested that not all residents had heeded evacuation advice.
Buildings damaged
2000 buildings
Sonoma County - February 26 to February 28, 2019
As of 28 February most of the damaged homes were in the Guerneville area.
Fatalities
1 person
Fernbridge, Loleta, Humboldt County - March 27 to March 27, 2019

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