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Record Driest Year in California, Parts of Oregon

By Jon Erdman
Published: January 2, 2014

California and parts of western Oregon witnessed their driest year on record in 2013, according to statistics from the National Weather Service (NWS).

Among the cities shattering their previous record dry year in 2013 were San Francisco, Los Angeles, Sacramento, Fresno, Medford, Ore., Salem, Ore. and Eugene, Ore.


In Downtown San Francisco, the single wettest day of 2013 was a mere 0.78" on November 20. Christmas 2012 was the last 1"+ rain day, there, according to the NWS office in Monterey, Calif.

Truly staggering was the fact that some locations picked up less than half the precipitation in 2013 of their previous record dry year, including Santa Cruz, Calif. (4.78" vs. old record of 11.85" in 1929) and the north San Francisco Bay suburb of Kentfield (7.80" vs. old record of 20.30" in 1939).

This is the meteorological equivalent of running a mile in less than two minutes! (The current world record for the mile is about 3 minutes 43 seconds).

Some of the precipitation deficits (compared to average) in 2013 were also truly remarkable:

  • Occidental, Calif.:  -41.54"
  • Big Sur, Calif.:  -37.62"
  • Crescent City, Calif.:  -35.11"
  • Ukiah, Calif.:  -29.85"
  • Eugene, Calif.:  -24.91"

Still not impressed? Even the nation's driest location, Death Valley, Calif. (2.17") picked up more rain this year than the following California locations:

  • Paso Robles, Calif. (1.92"...yearly average is 12.78")
  • King City, Calif. (1.98"...yearly average is 12.06")
  • Hanford, Calif. (1.99" at the airport site...yearly average is 10.10")

The paltry total in Los Angeles (3.60") was only slightly wetter than the nation's driest city, on average, Yuma, Ariz. (3.42") in 2013.

As a result, 85 percent of California was categorized in severe drought, according to the Dec. 24 Drought Monitor analysis, shown below. Much of the central valley as well as Kern, Santa Barbara, San Luis Obispo and Monterey Counties are considered in extreme drought, one drought category higher in the analysis.

Almost 60 percent of Oregon is in drought, primarily in the southern half of the state.

Western drought 2013

Drought status of the western U.S. as of Dec. 24, 2013. Areas of worse drought are indicated by the progressively more tan/brown contours. (NOAA/USDA/NDMC)

View of Lake Shasta on Jan. 1, 2014 showing the bathtub ring indicative of low lake levels. (Caltrans)

 

This has taken a toll on California's reservoir levels.

According to the California Department of Water Resources, many lakes and reservoirs are less than 40 percent capacity as of December 31, including Lake Shasta (37 percent), Folsom Lake (19 percent), Lake Oroville (36 percent) and San Luis Reservoir (30 percent).

Mandatory water conservation orders have been ordered for parts of California's Central Valley. According to a story in the Sacramento Bee, these water conservation orders could be the most severe in the area since the drought of 1976-77.

Critical to water supply in this part of the country is the buildup of winter snowpack in the mountains, whose meltwater in the spring replenishes reservoirs. 

According to the National Resources Conservation Service, snowpack (or more precisely, the estimated water content in the snow) is running only 23-34 percent of average in the Sierra, and a paltry 18-22 percent of average in the Oregon Cascades for the end of the year. 

Any Relief?

A critical season looms for the nation's most populous state, struggling through its third straight dry winter.

Background

Current West Coast Satellite

Current West Coast Satellite

Current West Coast Satellite

Current West Coast Satellite
San Francisco Average Rainfall

Average monthly rainfall (1981-2010) in San Francisco, Calif. (Data: NWS-Monterey, Calif.)

The culprit for this dearth of rain and mountain snow is a persistent ridge of high pressure aloft over the eastern north Pacific Ocean, which has diverted the jet stream, and hence, the storm track, well to the north into Canada. 

The few storm systems that have penetrated the West Coast recently have tended to drop south out of western Canada as relatively moisture-starved systems, rather than sweeping in ashore from west to east, tapping deeper moisture. 

Are there any signs of the pattern turning wetter? In a word, "no".

(WATCH: S.F. Forecast | L.A. Forecast)

The stubborn upper atmospheric high pressure we mentioned above appears poised to continue steering Pacific systems well north of California through the middle of January.

California has pronounced wet and dry seasons. San Francisco, for example, picks up 85 percent of their average yearly rainfall in a five-month period from November through March. Snowmelt provides up to three-quarters of the West's freshwater supply. In California, Sierra and to a lesser degree, Colorado River snowmelt, is crucial for reservoir replenishment.

In short, the Golden State needs a wet winter, with a combination of significant rain and mountain snow to replenish groundwater and reservoir levels. You could say California dreaming on such a winter's day for water resource managers includes a parade of Pacific storms. 

Unfortunately, using San Francisco as an example, one of the three wettest months has already passed. However, as you can see in the bar graph at right, average rainfall from January-April is roughly 12.5". 

It remains to be seen if the Pacific storm track will set up from later this winter through the spring to steer a parade of wet, Pacific storms to the thirsty Golden State.

  

 

MORE: California Wildfires May 2013

Camarillo, Calif.

Camarillo, Calif.

U.S. Forest Service firefighters walk a scorched ridge at the Springs fire on May 4, 2013 near Camarillo, California. (David McNew/Getty Images)

  • Camarillo, Calif.
  • Oxnard, Calif.
  • Camarillo, Calif.
  • Camarillo, Calif.
  • Hidden Valley, Calif.
  • Camarillo, Calif.
  • Point Mugu, Calif.
  • Point Mugu, Calif.
  • Camarillo, Calif.
  • Ventura County, Calif.
  • Glendale, Calif.
  • Camarillo, Calif.
  • Camarillo, Calif.
  • Newbury Park, Calif.
  • Newbury Park, Calif.
  • Southern California
  • Malibu, Calif.
  • Newbury Park, Calif.
  • Camarillo, Calif.
  • Ventura County, Calif.
  • Camarillo, Calif.
  • Ventura County, Calif.
  • Point Mugu, Calif.
  • Newbury Park, Calif.
  • Newbury Park, Calif.
  • Newbury Park, Calif.
  • Ventura County, Calif.
  • Newbury Park, Calif.
  • Point Mugu, Calif.

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