California's drought and recovery defying climate odds

During California's four-year drought between 2011 and 2015, lakes shrunk to historic lows. Photo by California Department of Water Resources/Florence Low

April 11 (UPI) -- New research suggests California's weather is defying the odds.

Meteorologists expected precipitation debts accrued during California's historic drought to last decades, but a new analysis suggests the debts could be erased this year.

Between October 2011 and September 2015, California experienced its driest four-year spell since scientists began tracking precipitation totals in 1895. Multiyear droughts are rare, two-year recoveries are even rarer. The effects were supposed to be long-lasting.

"The odds of the state completely recovering from its extreme dryness within two years are estimated at less than 1 percent," Eugene R. Wahl, a paleoclimatologist at the NOAA's National Centers for Environmental Information, said in a news release. "But, that may be what's happening right now if very wet conditions continue into spring."

Extreme El Niño conditions have buoyed rainfall totals during the last two years. As a result, the state's drought recovery has been faster than 80 percent of the bounce backs from similar dry spells.

Though official precipitation records only date back to 1895, researchers can use paleoclimatic data from soil cores, rock samples and other geochemical signatures to track historic precipitation totals and droughts.

Research suggests the drought between 2011 and 2015 was especially historic for two of California's climate regions, the San Joaquin Drainage and the South Coast Drainage. Scientists estimate the two climate divisions hadn't experienced a comparable four-year dry spell since at least 1571.

Models estimated the chance of the two regions recovering from such a spell in less than two years was effectively 0 percent.

The finings, detailed in the Journal of Climate, may force climate scientists to recalibrate prediction models as climate change increases the likelihood of both megadroughts and extreme precipitation.