A month of below-normal rainfall brought abnormally dry conditions and moderate drought conditions back to Southern California, and the Santa Clarita Valley, this December.
A recent report from the National Weather Service (NWS) Climate Prediction Center indicates that the “wet season has gotten off to a slow start in Southern California” with little rainfall reported for the water year, which began Oct. 1.
“Below-normal precipitation is favored from southern California through the southern Plains, which would promote additional drought expansion and intensification, especially given the recent dryness,” Forecaster Adam Allgood wrote in the report.
The Climate Prediction Center also noted that the drought persists in areas of Los Angeles County and is likely to develop throughout all of Southern California during the following three months.
The latest report from the United States Drought Monitor indicates that 44.30 percent of the state is abnormally dry and another 12.69 percent is in moderate drought, including an area spanning across the SCV.
Despite these results, the conditions are better than they were one year ago when 84.91 percent of California was abnormally dry, 70.11 percent was in moderate drought, 59.09 percent was in exceptional drought, 41.55 percent was in extreme drought and 19.75 percent was in severe drought.
Some forecasters said the dry conditions are not abnormal for the region during this year because the country is currently in a La Niña year when the Pacific is cooler and drier.
“We are in La Niña which historically can be dry for southern California; however, we have had some years where we had a lot of rain,” NWS Weather Specialist Bonnie Bartling said. “The Climate Prediction Center thinks it’s going to go from La Niña into neutral.”
Bartling said the NWS usually sees more rainfall in the area during the early months of the new year.
“It’s December and the rainfall year starts in October. January and February are usually our rainiest months,” she said. “It’s really early to say because we’re not in the rainiest months yet.”
SCV Water Agency
Despite the potential for additional rainfall this water year, the valley’s water resource manager, the Santa Clarita Valley Water Agency which includes Castaic Lake Water Agency and Newhall County Water District, is still preparing for a dry season with a scarce amount of water resources.
In early December, the agency told The Signal that water is still limited in the area, despite last year’s strong storms that brought the state out of its five-year drought.
“We’re continuing to see dry conditions throughout December,” said Dirk Marks, water resource manager for the Castaic Lake Water Agency. “We started off the year kind of decent, but December has been very dry due to the great pressure bridge hanging over the basin.”
The dry conditions have also impacted the agency’s watershed by three sub-basins that are all below normal, according to Marks.
These conditions also impacted the amount of water the agency will receive from Northern California as part of the State Water Project. Recently, the agency was given an allocation of 10 percent from the state.
“All of December has been pretty much very dry conditions throughout the state and, if you look at all the historic hydrology that’s occurred, it’s likely that that state water allocation will increase,” Marks said. “But there’s always the possibility that the dry conditions could persist and we’ll have that 10 percent allocation.”
If this allocation remains in place, the SCV Water Agency may look to use water banked for times when water is scarce.
“If conditions remain dry we would look to exercise some of our water banking programs in the San Joaquin Valley,” Marks said. “The two main ones are the Rosedale Banking Program and then we have the banking program with Semitropic Water Storage District.”
A lot of the state, including the SCV, receives some of its water from the snowpack in the Sierra Nevada Mountains.
According to the NWS Climate Prediction Center, “beneficial” snowfall fell across the northern and central Sierra Mountains.
However, the snowfall is still below normal for the southern, central and northern Sierras, which are reportedly at 28 percent of normal for Dec. 27, 2017.
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