Friday, April 1, 2016

California Drought: Things Are Better, But Not That Great

Last April 1, water managers tried to measure snow
in a high Sierra field, but came up empty. There should
be several feet of snow on the ground there
this time of year.  
Around the first of April last year, Frank Gehrke, chief of the California Cooperative Snow Surveys Program, strolled out into an alpine meadow in the Sierra Nevada mountains to measure the snowpack.

There was no snow to measure. Just green grass and dust. The moment encapsulated the dire water shortages California was facing in a record drought. The Sierra snowpack was just 5 percent of normal about a year ago.

This week, Gehrke strolled out into that same Sierra alpine meadow. This time he happily trudged through deep snow.

He poked a measuring stick into the slush and powder, and discovered the snow was 58 inches deep, says the Los Angeles Times.

The snow was packed down tight in that field. It held the equivalent of 26 inches of rain. That's just a wee bit below normal, 97 percent of normal to be exact.

The same Sierra meadow as above on March 30 this
year had a welcome snow cover of 58 inches.  
Which means, in terms of drought, things have vastly improved in California, but the state has a long way to go to recover to normal levels of moisture in the snow, in the ground, in the reservoirs, in the aquifers.

Thanks to El Nino, that periodic warming of the eastern Pacific Ocean, a number of wet storms slammed into California over the winter.

But compared to other big El Nino years the amount of precipitation in California over the past several months was "Meh." The state was counting on El Nino to deliver epic rains and snows.

El Nino only delivered something close to average for a winter. Not enough to get California out of the hole.

In fact, southern California in particular missed out on the storms. San Diego had the least amount of winter precipitation of any El Nino year on record. As noted, El Nino years in California are normally quite wet.

Last year, when Gehrke had no snow to measure, California Gov. Jerry Brown declared there would have to be a 25 percent reduction in California water use for the year, a goal the state largely met.

With this year's good but not spectacular snow and rain, the governor left the restrictions in place.

Here's how Gehrke describes the current situation, as reported in the Los Angeles Times:

"We're barely average. It stops the downward slide.....Now we're clearly looking at next year, and there are no reliable indicators of what next year will bring."

There's the rub. El Nino is fading, and we don't know what the weather patterns will be like next winter in California.

The Golden State gets next to no rain from late spring, through summer into the autumn. That's normal.

The question is, will the dry times return to California next winter? Will they get more welcome storms, or will the pattern flip back to dry?

Moreover, will temperatures continue to run well above normal, as they have in California for the past few years. High temperatures prematurely melt the Sierra snowpack and increase evaporation, hastening water losses.

These trends can have long term consequences. Farmers in California, especially in the south, are scaling back, because we are possibly in a "new normal" that features a drier California, notes Yale Climate Connection.

Maybe farms will just move north, and farming will be a thing of the past in southern California. Time will tell.

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