Already serious drought conditions across California and the American West are expected to worsen this spring into early summer, with hotter-than-normal temperatures, reduced chances of rain, and increased fire risk likely, federal forecasters said Thursday.
The next three months through the end of June show little to no drought relief, according to the National Oceanic and Atmospheric Administration, the parent agency of the National Weather Service.
“Concern is quite high as we go into the spring and early summer,” said Brad Pugh, operational drought lead for NOAA’s Climate Prediction Center in College Park, Maryland.
“The snowpack is below average for much of California, and there’s really very little time now to make up any precipitation deficits as we move into April.”
After two years of record-dry conditions, California had appeared to be coming out of its drought with heavy rains and snow in October and December. But January and February provided a complete reversal: They were the driest first two months in any year back to 1921, when records first began, in the Northern Sierra, the source of many of the watersheds that feed the some of the state’s biggest reservoirs.
March has continued that dry pattern, and winter is nearly over.
Meanwhile Thursday, the US Drought Monitor, a weekly report from NOAA, the U.S. Department of Agriculture and the University of Nebraska, reported that 93% of California is now in a severe drought — up from 87% a week ago — and 35% is in extreme drought, up from 13% last week.
All nine Bay Area counties are in severe drought, and the areas in extreme drought include much of the North Coast, including northern Sonoma and Mendocino counties, and the San Joaquin Valley, where farmers are already running short of water.
The winter rains that California did receive helped to temporarily reduce the amount of the state that is in extreme drought. In early December before several big atmospheric river storms arrived, 80% of the state was in extreme drought.
But the trends, once headed in the right direction, now show a worsening of conditions again. And with seven months of hot, dry weather likely until the winter rainy season begins again next November, soils and vegetation will be drying out to dangerous levels, bringing an increased risk of wildfires for the third year in a row.
Scientists say climate change is making droughts worse across California, the West and other parts of the world. For many young people in California, drought has persisted for most of their lives.
The 10 hottest years since 1880 on earth all have occurred since 2005, according to NASA and NOAA. When droughts do occur, as they have in the past, they are more severe now, scientists say.
“Warmer temperatures lead to increased evaporation, and decreased moisture in soils and reservoirs,” said Chris Field, director of Stanford University’s Woods Institute for the Environment.
On Friday, officials at the state Department of Water Resources are expected to reduce water allocations to cities and farms from the State Water Project, a massive system of dams, canals and pumps that stretches more than 600 miles from Oroville reservoir in Butte County to Lake Perris in Riverside County.
After the December rains, state officials said that most areas would receive 15% of their contracted water from the project. But given the dismal January, February and March conditions so far, that number is certain to fall. Roughly 25 million people in California, including residents of Santa Clara County, southern Alameda County, Los Angeles and San Diego, receive State Water Project water.
Reductions in that water mean more local water restrictions, such as limits on lawn watering and higher rates for excessive use, are likely in cities across California this summer, along with increased incentives to conserve, such as rebates for water-efficient appliances and subsidies for residents who voluntary replace lawns with drought-tolerant landscaping.
If it seems like water shortages and low reservoirs are becoming more common in California and much of the West, that’s because they are, at least in the past 20 years.
“You have to think in the context of changing climate, and since the beginning of the 21st century about 3 out of 4 years in California have been drought years,” said Brad Rippey, a meteorologist with the US Department of Agriculture.
Not only people in cities, but farmers are having to adapt to those changing conditions, he added.
“The new normal is drought more often than not,” Rippey said.
This week Lake Powell on the Colorado River in Arizona and Utah fell to its lowest level in history. Lake Mead, downstream near Las Vegas, has fallen to similarly low levels. The two reservoirs, the largest in the West, provide electricity and water to millions of people in Arizona, Nevada and Southern California.
“There is a human contribution to the ongoing drought,” said Russell Vose, chief of NOAA’s climatic analysis branch. “It’s not a little bit. It’s definitely making a contribution. Temperatures are going up, and with below-normal precipitation you’ve got a pretty good recipe for drought.
“Regional drought severity and fire risk will probably worsen in the decades ahead,” he said.
Source: www.mercurynews.com