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On This Day in 1982- Heavy Rain, Deadly Landslides End in Bay Area
January 5, 2021 at 04:00 AM EST
By WeatherBug's Christopher Smith
California gets most of its yearly precipitation in the winter months with January leading the pack as traditionally the wettest month of the year. Too much rain often triggers flooding and mudslides such as a storm system that walloped central California and the San Francisco Bay area and ended 39 years ago today.
The wettest California winters are usually as a result of a global climate pattern called an El Niño, which causes an active storm track to cut through the southern half of the state. However, the winter of 1982 was unique in which it was neither an El Niño, nor the opposite, a La Niña, but rather was neutral.
Troubling signs started in 1982 as a stubborn low pressure anchored itself across the Golden State and strong westerly wind up to jet stream level funneled tropical moisture thousands of miles from near Hawaii into the state. Called the “Pineapple Express,” these events often produce copious rain and damage property as well as disrupt travel. This storm was no different as it unleashed heavy rain across central California starting on January 3.
The rain intensified into early January 4, with rainfall rates approaching one inch per hour in the Santa Cruz Mountains south of San Francisco. Besides the downpours, the real problem occurred with the duration of the event.
For nearly 30 hours straight, moderate to heavy rain was falling on soil that was almost at full water capacity from previous storms. While San Francisco and Oakland Calif., recorded 4 to 6 inches of rain, the slopes near the San Lorenzo Valley south of the city registered almost two feet of rain!
As a result of the heavy rain, multiple landslides and mud and debris flows tore through the hills across the Bay Area. Around 7,800 homes and businesses were damaged with nearly 300 more destroyed. Parts of Route 101 were hit with mudslides, stranding hundreds of San Francisco residents on the road and more than 72,000 customers were in the dark as powerlines were wiped across the hillsides.
By the time the storm finished on January 5, 33 people lost their lives as a result of the flooding and landslides. The storm’s price tag was a whopping $765 million in damage (today’s currency).
The combination of this early-January storm and two separate rainfall events later in the month pushed monthly rainfall totals across central California to more than double their average. Areas such as San Francisco recorded 8.81 inches of rain for the month, compared to the January average of 4.19 inches.
Source: weather.gov
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Story Image: A house destroyed near Aptos Creek, south of San Francisco, as a result of the deluge on the early January 1982 deluge (usgs.gov).
The wettest California winters are usually as a result of a global climate pattern called an El Niño, which causes an active storm track to cut through the southern half of the state. However, the winter of 1982 was unique in which it was neither an El Niño, nor the opposite, a La Niña, but rather was neutral.
Troubling signs started in 1982 as a stubborn low pressure anchored itself across the Golden State and strong westerly wind up to jet stream level funneled tropical moisture thousands of miles from near Hawaii into the state. Called the “Pineapple Express,” these events often produce copious rain and damage property as well as disrupt travel. This storm was no different as it unleashed heavy rain across central California starting on January 3.
The rain intensified into early January 4, with rainfall rates approaching one inch per hour in the Santa Cruz Mountains south of San Francisco. Besides the downpours, the real problem occurred with the duration of the event.
For nearly 30 hours straight, moderate to heavy rain was falling on soil that was almost at full water capacity from previous storms. While San Francisco and Oakland Calif., recorded 4 to 6 inches of rain, the slopes near the San Lorenzo Valley south of the city registered almost two feet of rain!
As a result of the heavy rain, multiple landslides and mud and debris flows tore through the hills across the Bay Area. Around 7,800 homes and businesses were damaged with nearly 300 more destroyed. Parts of Route 101 were hit with mudslides, stranding hundreds of San Francisco residents on the road and more than 72,000 customers were in the dark as powerlines were wiped across the hillsides.
By the time the storm finished on January 5, 33 people lost their lives as a result of the flooding and landslides. The storm’s price tag was a whopping $765 million in damage (today’s currency).
The combination of this early-January storm and two separate rainfall events later in the month pushed monthly rainfall totals across central California to more than double their average. Areas such as San Francisco recorded 8.81 inches of rain for the month, compared to the January average of 4.19 inches.
Source: weather.gov
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Story Image: A house destroyed near Aptos Creek, south of San Francisco, as a result of the deluge on the early January 1982 deluge (usgs.gov).