Explosion in extreme drought in California

By Jason Samenow
January 16, 2014
Washington Post

In just a week’s time, the percent of California in extreme drought skyrocketed from 28 to 63 percent, as the state deals with one of its driest stretches in recorded history.

The U.S. Drought Monitor reports a dismal state of affairs for much of the state:

Water-year precipitation in most of the [extreme drought] area was now less than 20 percent of normal, with locales from the southern San Joaquin Valley to the Pacific Coast reporting less than 10 percent of normal. Mountain snowpacks in the Sierra Nevada continued to dwindle as well, with [snow water equivalent] averaging between 10 and 30 percent of normal (10th percentile or lower, with many locations now in the bottom 5th percentile). Soil moisture across the northern two-thirds of California remained in very short supply…

Satellite view of snow cover over Sierra Nevada mountain range in January 2013 vs. January 2014 (NOAA)

The lack of rain and snow so far in 2014 follows California’s driest year on record.

The outlook for next 6-10 days is not encouraging.

“Little — if any — drought relief is expected from the Plains to the Pacific Coast states, with precipitation during the upcoming monitoring period mostly confined to the northeastern quarter of the nation,” the Drought Monitor says.

The Weather Channel notes many areas of California may have record dry Januarys:

According to the National Weather Service in Monterey, Calif., San Francisco has never seen a January with less than a quarter inch of rain. With just one-hundredth of an inch of rain so far this month, this record could be in jeopardy. In addition, San Francisco has only recorded five days with measurable rain since Nov. 1 compared to an average of 30 days during the period from Nov. 1 to Jan. 31.

January is one of the two wettest months of the year in Los Angeles with an average of 3.12 inches of rain. If the second half of the month finishes with no rain, January 2014 would join only four other Januarys in the last 100 years that no rain was recorded (2003, 1976, 1972, 1948).

A report in the LA Times says water restrictions are likely in the pipeline for the northern part of the state.

“As the winter progresses with no break from last year’s parched conditions, concern is mounting that California may be headed for a replay of the big drought of the late 1980s through the early 1990s, or even worse, 1977,” the Times piece notes.

California governor Jerry Brown says a state-wide drought declaration is “coming”, which could conceivably help officials maximize water resources by facilitating water transfers between agencies.

European weather model simulation for January 16 shows giant blocking ridge of high pressure blocking storms from hitting California (WeatherBell.com)

The drought is linked to a huge ridge of high pressure over the West Coast which has acted like a giant shield against incoming weather systems. The jet stream has steered weather systems up and over this ridge, also helping to direct cold air out of Canada towards the central and eastern U.S.

If there’s any glimmer of hope for California, it’s that the rainy season extends through March and the historic record shows instances where droughts like this ended quickly. Consider this excerpt from a piece in the San Jose Mercury News:

“In California, most of our water in the reservoirs comes from just a handful of big storms each winter,” said Daniel Swain, a Ph.D. candidate at Stanford University in the Department of Environmental Earth System Science who coined the term “Ridiculously Resilient Ridge” on his blog, weatherwest.com.

“If we do manage to get a few decent storms, we could definitely get enough water to stave off the worst consequences of a really extreme water shortage,” he said.

Adds the LA Times:

In early 2009, the state echoed with ominous drought warnings. Then a series of February storms fattened the snowpack and filled rain gauges. A “Miracle March” in 1991 brought triple the month’s normal precipitation.

NOAA’s long range outlook, however, doesn’t favor in a reversal in this dry pattern.

NOAA’s forecast through April is for drought to persist or intensify throughout California.

Jason Samenow is the Capital Weather Gang's chief meteorologist and serves as the Washington Post's Weather Editor. He earned BA and MS degrees in atmospheric science from the University of Virginia and University of Wisconsin-Madison.