Drought Continues to Hammer California; Little Relief in Sight
John Steinbeck and Sonora Babb painted vivid pictures of the Dust Bowl in their novels The Grapes of Wrath and Whose Names Are Unknown. The stories showed the migration of impoverished farmers west from the Great Plains to California, where some found work and others found more pain in the orchards and fields of the Golden State.
Now, eight decades later, Mother Nature has flipped the script and has sharply depleted the water supply of the nation's top agriculture state just like she did in Oklahoma, Texas, Kansas, and other Plains states in the 1930s. Now, California's agriculture and population in general is in danger of massive losses because of a years-long drought. The drought is yet to cause a human exodus like it did in the Plains during the Dust Bowl, but it is already causing massive cuts in crop and livestock production in the nation's largest agriculture state.
California's agriculture is the most diverse in the U.S. in terms of the number of crops grown. With dramatic cuts in production because of the drought, many expect prices for many products to skyrocket as supplies dwindle. As of midsummer, NOAA data showed 100% of the state's hay, cattle, and winter wheat crops, for example, were seeing production cutbacks because of the drought; almost 60% of the state's winter wheat was under "exceptional" drought, and 58% of the state's area where cattle are raised was in the same category. That's expected to cause major cuts in the state's cattle herd, which has been around 5.3 million head in the last 2 years. Total crop area in the state has already been sharply reduced; in 2012, just shy of 4.4 million acres were planted to "principal crops," according to USDA-NASS. This year, NASS shows 3.58 million acres planted.
While the dryness that gripped the nation's center two years ago has largely abated, the drought has only intensified in California and neighboring states; Nevada is, according to the U.S. Drought Monitor, 100% under some form of drought, while 99.8% of California is in the same condition. Of the latter state, 23% is in the worst category -- "exceptional" -- of drought, according to a report from the California-Nevada Climate Applications Program (CNAP) administered by the National Oceanic and Atmospheric Administration (NOAA) and National Integrated Drought Information System (NIDIS).
Graphic courtesy U.S. Drought Monitor
Drought is nothing new to California, though. A CNAP report shows there's a water shortage -- though not as severe as the one underway right now -- in the state about three times a decade. And, research shows there have even been "megadroughts," or those that last as long as 100 years, in the past. More research is being conducted right now to determine what conditions could trigger another of these massive dry spells in the future.
"The year 1977 is often used as a model of extreme dryness in California. Statewide accumulation in water years 1974-77 was 45 inches statewide, compared to an average of 70 inches," according to a CNAP report. "The three-water year period of 2011-14 has less accumulated precipitation than the period 1974-77, and so sets a new record for low three-year statewide precipitation accumulation totals in the historical record."
Precipitation is surprisingly just one piece of the California drought puzzle. On top of consecutive years with sharply below-normal rainfall, there's been an atmospheric angle, one in which the adjacent Pacific Ocean has played a role.
"The immediate cause of California’s 2014 drought can be traced to the altered route of atmospheric water vapor, which is necessary for strong winter precipitation in the state. Ordinarily, water evaporates from the ocean in the warm Tropical Pacific Ocean and winds carry that water vapor to the U.S. West Coast," according to a CNAP report. "However, in 2014 the water vapor transport split into two branches and ended up going either north or south of California. Why did the water vapor diverge from its usual route across the Pacific? One reason was the presence of a 'ridge' of high atmospheric pressures off the northwest coast of North America. This ridge steered water vapor away from California."
Last spring, climatologists reached agreement that El Niño was making a comeback. When the Southern Oscillation Index swings away from La Niña and toward El Niño, that typically means more moisture for the West Coast of the U.S. So, will that do much to ease the Golden State drought if El Niño does return? The short answer is: It depends.
"El Niño typically brings wetter-than-normal conditions to much of the southern half of California and the interior Southwestern U.S. As the summer of 2014 progressed, it looked likely that any El Niño that formed would be relatively mild," according to a CNAP report. "There is a severe deficit, which manifests in low reservoir levels and dry soil, with attendant hardships on farmers and other users. The heavy precipitation needed to erase the current drought has historically only been seen during particularly strong El Niños, but even then it is not guaranteed; some strong events have near-normal precipitation. Precipitation in the northern parts of the state are less affected by El Niño than the South Coast drainage. Overall, records suggest that if an El Niño develops, only a strong event is likely to have a chance of erasing the current drought."
A report by CNAP researcher Mike Dettinger outlines the likelihood that El Niño will alter current drought conditions, and the numbers aren't pretty.
"Any way you dice it, we are still going to end up about 10 inches short of where we should be as a state. Looking only at El Niño (presumably wet) years, [research] shows there is a 21% chance we won’t even get to fill in the hold from water year 2013/2014," according to a CNAP blog post outlining Dettinger's research. "And we see the 8% chance that we might fill in the hole and get back to normal."
Looking ahead through fall, the chances of the drought easing in California are slim. According to the NOAA Climate Prediction Center, an area stretching from the eastern half of Nevada to western Kansas, south to west Texas and north to the Canadian border has chances for "above-normal precipitation." On top of the Golden State's exclusion from that area, temperatures are expected to be above-normal as well, according to NOAA Climate Prediction Center meteorologist David Miskus. This adds up to the likelihood that the drought will "persist or intensify" through late fall and early winter.
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