Harbinger of things to come?

California drought: Scientists puzzled by persistence of blocking 'ridge'
Many states have seen an easing of drought conditions, but not California, mired in its worst in more than a century. The culprit, a high pressure ridge parked offshore that is blocking winter storms.
By Gloria Goodale – Tue, Jan 21, 2014

While much of the United States has experienced a weather year with fewer extremes and an easing drought, the record-breaking California drought – the worst since 1895 – is not leaving the region anytime soon, according to climatologists.

The unseasonal balmy but dry weather is the result of an equally unprecedented high pressure ridge lurking offshore and blocking the typical winter storms needed to drop precipitation all along the West Coast.

This ridge has persisted for 13 months and the longer it lingers, the less likely it is to leave, points out climatologist Brian Fuchs, from the National Drought Mitigation Center in Lincoln, Nebraska. This high pressure ridge system is feeding on itself, “creating a sort of perfect environment for perpetuating the dry conditions” it creates, he says.

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High-pressure systems are not uncommon, but it is abnormal for them to hang around uninterrupted for so long. “This makes it even harder as winter storms approach for them to break through and change that pattern,” he adds.

This recent dry spell accentuates a continuing background condition of prevailing drought across much of the Southwestern US, notes Christopher Williams, a specialist in US drought conditions and an assistant professor at Clark University’s Graduate School of Geography in Worcester, Mass.

Precipitation is below 20 percent of normal and signs of the drought impact run across the region, including low river flows, low snow packs, low reservoir levels, and out-of-season wildfires.

“Wintertime shortages are particularly worrisome,” adds Mr. Williams via e-mail, “because winter is a key time of year for building up water supplies that carry the West through the rest of the year.” What is worse, he says, “shortfalls extend well beyond the state of California itself, reaching nearly all of the remote regions on which the California water supply network relies, particularly the Colorado River Basin.”

Scientists are uncertain as to why the ridge has stubbornly refused to break down and allow incoming storms to hit land. Climate change may be one of many factors, suggests Mr. Fuchs.

“It’s always difficult to know if a specific disaster or storm is tied to climate change,” he says, but over the course of decades it is possible to see large trends moving in a certain direction. “You can’t really pinpoint one thing, but you can say that over a period of decades there is less snow accumulation and warmer temperatures, and climate change is playing a part in that,” he adds.

On Friday, California Gov. Jerry Brown declared a drought emergency, calling for a 20-percent voluntary conservation effort state-wide.

This is just the beginning, says Doug Parker, director of the California Institute for Water Resources. “We have seen essentially no rain or snowfall this year and short- and long-term forecasts are bleak for California,” says Mr. Parker via e-mail, adding that this means that California will have very low water deliveries to much of its agricultural sector.

This agriculture is an important part of the state’s economy, points out Parker. “This will lead to fallowing of farmland which will reduce output and reduce employment,” he suggests, adding that could drive up the prices of certain commodities. In addition, the dairy and meat sectors will be particularly hard hit, he notes, as those sectors will have to import feed.

The drought throughout the West will impact other states similarly, points out Parker.

The drought will increase pressure on already over-used groundwater supplies, says Parker. “We have seen dropping groundwater levels in many parts of the state. We expect growers to increase use of groundwater, especially for tree and vine crops. This will accelerate the decline in groundwater,” he adds.

Little currently on the horizon offers much hope for change, says California climatologist Mike Anderson, with the Department of Water Resources.

This offshore ridge is very stable, he says, adding, “this is good news if you want nice weather, but if you want precipitation it is not.”

Driest California in 500 Years?
By Kate Galbraith | The Daily Beast – 9 hrs ago



SAN FRANCISCO—Weird things are happening in California. Bears, normally hibernating at this time of year, have climbed out of their caves to search for food. Some visitors to Tahoe are renting bikes, not skis.

As the East Coast digs out from its latest snow dump, Californians can only look on enviously. Here, the snowpack in the Sierra Nevada Mountains, the state’s great water-supply source, stands at a scary 13 percent of normal. California suffered its driest year on record in 2013, but what’s yet to come is even more terrifying. Federal forecasters predict that the drought will continue or intensify through at least April—by which time, the “rainy” season will be over.


The Golden State should probably be panicking more than it is. Reservoir levels are falling, but only a few cities, including Sacramento and the Sonoma County town of Healdsburg, have mandated water-use reductions. Both have instituted cuts on the order of 20 percent for every household. Governor Jerry Brown has asked everyone to make voluntary cuts, but as drought-stricken Midland, Texas, learned a few years ago, voluntary never quite does it. (An only-in-California water-saving tip I’ve seen: go around in the buff, to save on the need to wash clothes.)

The problem is a huge atmospheric ridge of high-pressure that’s been hovering off the coast for an unprecedented 13 months. Storms can’t break through, so they go around and over it. The really worrying part, as the Christian Science Monitor explained this week, is that the longer the ridge hangs around, the sturdier it gets. Nobody knows when it will disband. (And no, we also don’t yet know if all this is linked to climate change, but California will doubtless be glad to trumpet a connection.)

“This could potentially be the driest water year in 500 years,” says B. Lynn Ingram, a University of California at Berkeley paleoclimatologist.

Assuming the drought continues, it’s going to have huge and complex effects. Among them:


* Farmers are going to fallow land or pump lots of groundwater, depleting the aquifers for future years. (And water-stealing illegal pot-growers may get pursued more vigorously.) * Some towns may run out out of water; the small community of Willits in Mendocino, has only a 100-day supply left. * Summer wildfires were bad last year (remember the huge Yosemite blaze?)—but with the state even crisper, things may now get worse. * Some rivers will go dry. (Fish always seem to have the last dibs on water in times of drought.) * Air pollution will continue to be a problem. The unusually hot, stagnant air has made it the worst pollution season ever in the San Joaquin Valley. It’s triggered purple alert days in Bakersfield, worse than the usual red—and that’s may continue for awhile. Bay Area winter pollution is also nearing a record.

Then there’s politics. Water was already bound to be a big topic this year in California, what with the state’s $25 billion proposal to fix the Delta, the confluence of two rivers where much Sierra Nevada water flows through. It’s an incredible sum—far more than, say, the $2 billion in extra spending that Texas agonized over last year. But voters may be more open after a few dry years.


It bears emphasizing that the drought is not solely a California problem. It’s a long-term Western problem and a big one. Some Oregon towns also recorded their driest year on record in 2013. If you look at a drought map, you’ll see that rainfall is below average for a huge swathe of the West. The New York Times ran a depressing piece recently on the shrinking of the Colorado River, a key source of water for California and other Western states.

Another state worth watching in the context of drought is Texas. That state had its lowest rainfall (and its second-hottest weather) in recorded history in 2011. The rains have returned to much of the state, but some reservoir levels are still worryingly low. The lakes that supply Austin, for instance, are just 38 percent full, far below normal for this time of year. Unless big storms hit, summer evaporation and lawn-watering is going to push things back into the critical mode. West Texas is in worse shape, with its big remaining reservoir less than 14 percent full.


At some point, what with population growth and climate change, the western United States will face a water reckoning. That time may be now.