Great Bakersfield Dust Storm of 1977
Encyclopedia
The Great Bakersfield Dust Storm of 1977 (also known as the Southern San Joaquin Valley Dust Storm) was a severe dust storm
Dust storm
A dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...

 in the Southern San Joaquin Valley
San Joaquin Valley
The San Joaquin Valley is the area of the Central Valley of California that lies south of the Sacramento – San Joaquin River Delta in Stockton...

, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. It started in the late evening on December 19, 1977 and ended in the afternoon of December 21. It resulted in 3 deaths and $40 million in damages (does not include subsequent agricultural losses).

The Great Dust Storm

December 19 started like most cold winter days. At 11:00 pm, temperature was 44 °F (6.7 °C) with a light northwestern wind. By 11:30 pm, the weather had started to change. The temperature began to warm up and the wind had shifted direction. It also started to grow in strength and dust started to restrict visibility. In the very early morning, the next day, power was sporadic throughout the city. The wind was stronger, but people went to work and school was still in session. However, by 9:00 am, school was cancelled. Parents were requested to pick up their children because of the concern that high-profile buses could blow over.

By late morning, the wind was blowing hard, and sounded like a loud roar. Enough dust was in the air that it blocked out the sun. Roads into and out of the southern valley were closed. Only one TV station and two or three AM radio stations continued to have power and were able to broadcast. Also, since Bakersfield did not have a direct feed to national news broadcast, no one outside of the area knew the severity of the situation.

Wind continued to blow throughout the afternoon and evening. Swamp cooler
Swamp cooler
An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling differs from typical air conditioning systems which use vapor-compression or absorption refrigeration cycles. Evaporative cooling works by employing water's large enthalpy of vaporization...

s on the roof of buildings blew off. Windows were shattering and store signs were blowing in the wind. It was described as if a twister was unrolled and blew up the valley in a sheet. Farther north in the valley, Fresno
Fresno, California
Fresno is a city in central California, United States, the county seat of Fresno County. As of the 2010 census, the city's population was 510,365, making it the fifth largest city in California, the largest inland city in California, and the 34th largest in the nation...

 was having a typical December rain. When the dust reached the rain, it turned into mud. It fell in sheets from the sky.

People awoke the next morning to a dark sky. The wind had blown throughout the night and was continuing in the morning. Schools remained closed that day. By the afternoon, the wind began to subside, and the air started to clear.

The Aftermath

By the afternoon of December 21, people began to see the damage from the dust storm. The result was devastating. Trees, fences, and swamp coolers had blown down throughout the region. Below grade freeways, canals, and creeks were buried. Dirt had piled up on the south side of the buildings. Dust had seeped into to cracks and crevices of buildings, filling the interior with a layer of dust. After several of days, the roads were reopened and news reports started leaving the valley. People also started digging out and cleaning up. By spring, not all of the canals and creeks were cleared. As a result, the rain caused them to flood.

In total, 3 people died and $40 million in damages. Over 25 million cubic feet of top soil from grazing land alone was moved. Wind was measured at 192 miles per hour (85.8 m/s) in Arvin
Arvin, California
Arvin is a city in Kern County, in the United States. Arvin is located southeast of Bakersfield, at an elevation of 449 feet . As of the 2010 census, the population was 19,304, up from 12,956 at the 2000 census....

 (southeast of Bakersfield). In the foothills, the wind was measured at 189 miles per hour (84.5 m/s). In the mountain passes, it was 199 miles per hour (89 m/s).

The Cause

The great dust storm was caused by many different events. There had been a drought in the region for several years, which caused the ground to be dry. Cotton had recently been plowed under (end of the season) but the winter crop had not taken root yet. This caused the soil to be loose.

The high winds were also caused by a series of events. Over the Great Basin
Great Basin
The Great Basin is the largest area of contiguous endorheic watersheds in North America and is noted for its arid conditions and Basin and Range topography that varies from the North American low point at Badwater Basin to the highest point of the contiguous United States, less than away at the...

, which is located in Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

 and Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

, was very cold and heavy air (high pressure). A very strong low pressure system was approaching the northwest coast of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. A mercury reading of 0.10 inches of pressure gradient force (difference of pressure between two points) is typically needed for a 10 to 12 miles per hour (16 to 19 km/h) northwestern wind. That day, the reading was 0.60 inches.
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