California needs more than a 'miracle March' this time

The Fresno BeeJanuary 25, 2014 

The Snow Water Equivalents in the Sierra Nevada mountain range in California are abnormally low for this time of year, as seen in this image comparing 2013, left, to 2014, right.

NASA/NOAA

For four dry winters, a 200-mile-long blob of high pressure had haunted the atmosphere near California's coast, pushing away storm after storm until March 1991.

The high pressure suddenly moved, and a river of storms hammered the state. Fresno got 70% of an entire rainfall season in that one month, yet the winter fell short of average in Fresno and most of California.

Twenty-three years later, another freakish bump in the atmosphere has created a winter drier than any in the drought from 1987 to 1992.

A miracle March would help, but it would not prevent the third drought year in a row for California, meteorologists say. In addition to a miracle March, the state needs a fabulous February and an amazing April.

The odds are one in 200 that California will get that kind of rain and snow to reach average now, says the National Weather Service in Hanford. It's not welcome news this month, which probably will be Fresno's first rainless January since 1883.

"There's no doubt in my mind that it will rain again this season," said weather service meteorologist Paul Iniguez. "But it doesn't look likely that we will catch up."

California's capricious wet seasons are more volatile than most places in the United States, climatologists say. But even here, this dry winter is unprecedented in the meteorological records.

In fossil records, the winter might be the worst over the past five centuries, according to a paleoclimatologist at the University of California at Berkeley.

In the San Joaquin Valley, if it doesn't rain by the end of the month, Fresno's .73 of an inch of rain would be the driest July to January on record. The precipitation year runs from July 1 to the following June 30.

Rainfall totals in Paso Robles and Santa Maria are 8% of average. Like Fresno, Sacramento hasn't seen rain in seven weeks.

Rain and snow totals in the Northern and Southern Sierra are below the driest years on record — 1976-1977 and 1923-1924. The Sierra snowpack is a ghostly 13% of average.

State climatologist Mike Anderson adds perspective: California's biggest rain and snow months are December, January and February.

"We've already taken a pass on two of the three," he said. "February still could be a big month. But after that, there's a lot of variability in the precipitation in this state."

Another hurdle for meteorologists who are trying to make sense of the winter: It's tough to find comparable years that were this dry this far into the season.

The best comparison for Fresno is 1917-18. From July to January that year, Fresno had only .96 of an inch of rain. On average, Fresno would have more than five inches by Feb. 1.

But in 1918, the city had back-to-back monster rainfall months — 4.59 inches in February and 4.19 inches in March. Both rank among the 10 wettest ever for February and March.

At the same time, it is only one year in more than a century of record-keeping — interesting, but not enough to be part of any pattern.

Fresno-area meteorologist Steve Johnson said he looks at many different sets of data, including two broad indexes describing rain and snow in areas feeding water into California's two longest rivers — the Sacramento and the San Joaquin.

The San Joaquin River index brings together rain and snow totals from Yosemite Valley, Hetch Hetchy, Huntington Lake, North Fork and Calaveras Big Trees State Park north of Yosemite National Park.

With a total of 3 inches so far in the index, it too is tracking below the driest years on record. On average, the region would have more than 20 inches by now.

Johnson said it means the already dry mountains and foothills — following two drought years — are now very dry. Any precipitation that does fall will be absorbed into the landscape, which will cut down the runoff into depleted reservoirs, he said.

Johnson added that evaporation since December has probably taken more than 3 inches worth of rain from surrounding reservoirs. With the exception of a light mountain and foothill spritzing last week, most of Central California hasn't seen rain since Dec. 7.

"We're talking about a catastrophic year now," Johnson said. "There's a little snow above 11,000 feet, but there's nothing else going on. There's no recovering unless something very unusual happens."

What's going on here? Most meteorologists say the chaos of the Earth's weather does not give them many clues this year.

The Pacific Ocean is neither in a warm-water El Niño, which can mean a wet winter in California, nor a cool-water La Niña, which can mean dry. The ocean is neutral, said research meteorologist Dan Cayan of the Scripps Institution of Oceanography.

Cayan does not connect the unusual dry season with other cycles in the ocean or climate change. He said California has experienced extended drought in centuries past, and this year could be part of nature.

"Things are bound to turn around," he said. "I think the best thing we can do is keep our fingers crossed right now."

The reporter can be reached at (559) 441-6316, mgrossi@fresnobee.com or @markgrossi on Twitter.