Rain is in the forecast this week for Merced County and much of the San Joaquin Valley, but whatever falls won’t come close to ending drought conditions, experts said.
The National Weather Service in Hanford is predicting a 30 percent chance of rain Wednesday night , increasing to 50 percent on Thursday, meteorologist Cindy Bean said. Overall, the storm system could bring between one- and two-tenths of an inch of rain, she said.
“They’ll get some snow above 7,000 feet, but here in the Valley we’re expecting lighter amounts of rain,” Bean said. “But it’s the first rain we’ve had in quite a while, so we’ll take it.”
The Merced area has seen no rain this month, and only 1.02 inches for the season. The normal amount for this time of year is 6.17 inches.
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On Jan. 17, Gov. Jerry Brown declared a drought in California and directed state officials to take all necessary action to prepare and assist farmers and communities that are economically affected by dry conditions.
Bean said it would take “a lot of systems and lot more rain” to make any noticeable dent in the drought.
The National Weather Service considers a drought to be two to three consecutive years of below-average rainfall. The weather service’s Climate Prediction Center is looking at a 40 percent chance of precipitation for most of the state between February and April.
“Any opportunity for rain would make us happy,” said David Robinson, agriculture commissioner for Merced County.
The lack of rain has begun to have an effect on the roughly 562,000 acres of range land in Merced County.
A sizable portion of the grass-growing season has passed, and Robinson said that means ranchers are having to buy more expensive feed for their animals. If rain comes next month, he said, the ranchers may be able to salvage some of the growing season. “That’s a crisis that’s ongoing at this point,” he said.
On the other side of the agriculture industry are growers who are dependent on the San Luis Reservoir. The reservoir near Los Banos is at the very low 340,000 acre-feet level. An acre-foot, which amounts to roughly 325,000 gallons of water, is the amount it would take to cover one acre 1 foot deep.
Lake McClure, which is east of Snelling, is filled to about one-quarter of its capacity at about 226,000 acre-feet of water.
Growers of almonds, walnuts, grapes and other permanent crops are turning to well water earlier than usual, Robinson said. Paying for the diesel fuel or electricity to pump water also costs growers.
So growers are hoping for a wet February and March. “You can always hope,” Robinson said.
Some rain in the Valley means snow in the mountains, where the lack thereof has hurt hydrology research.
The northern Sierra snowpack is 5 percent of normal, according to measurements by the California Department of Water Resources. The monthly snow survey is intended to measure snow depth and water content in a region crucial to statewide water supplies.
UC Merced’s Sierra Nevada Research Institute, which is funded by the National Science Foundation, is researching ways to better estimate and measure the snowpack and water supply. The institute studies how forest vegetation, soil and other factors change the water runoff.
“Is there more runoff? Is there more snow on the ground?” said Roger Bales, who heads the institute. “When it’s a really dry year, you have trouble separating the signal from the noise.”
The institute has been able to gather data on years with limited snowfall, Bales said, but it needs to be able to study heavy years as well. It’s research such as Bales’ that cities use to plan for their water supply.
The expected snowfall this week is a welcome sight, but Bales said forecasts can be unreliable. He said the average for the mountains is 3 feet of snow between October and April.
“Two-tenths is, as they say, a drop in the bucket,” Bales said, “or a drop in the water supply,” referring to the expected amount of rain.
The National Weather Service reminds drivers to be careful when the rain falls, because dirt and oils have built up and roads will become slick.