Is Valley drought back? 2018 ends as a drier-than-normal year

See where Millerton Lake’s water levels are at in this drone video

Although the seven-year drought was declared over in 2017, 2018 was a dry year and some are worried the lack of rainfall may put California back into a drought.
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Although the seven-year drought was declared over in 2017, 2018 was a dry year and some are worried the lack of rainfall may put California back into a drought.

In a state where dead trees in the Sierra Nevada still stand as a testament to a severe seven-year stretch of dry weather that ended in 2017, some nervously wonder whether the state may slide back into a drought.

In the eastern Pacific Ocean near the equator, ocean temperatures are pretty stable. That means there’s no El Niño or La Niña sitting out there to help drive a chain of storms to dump rainfall on the Valley and snow in the Sierra Nevada as the calendar closes on 2018.

“We suffered through a long, hot, dry summer and fall,” said Kevin Lynott, a meteorologist with the National Weather Service in Hanford. “We caught up a little bit in November and December, but not enough to bring us to normal precipitation for the year.”

As of Friday, Fresno had received 8.65 inches of rainfall – more than 2 1/2 inches less than the normal yearly precipitation of 11.22 inches, Lynott said. Merced got about 1.5 inches of rain for the month, about a quarter-inch more than a normal year.

And things aren’t looking to get much better anytime soon. “We’re expecting a drier pattern at least through the first half of January. … We think the pattern might change in late January or February, and we’re looking for more near-normal or slightly above normal in February and into March.”

“But it’s very safe to say the next few weeks we’re going to be pretty dry. It doesn’t look like we’re going to have a banner year like we did two years ago,” Lynott added.

In the hills east of Fresno, Pine Flat Reservoir is at only about 29 percent of its million-acre-foot capacity, while Millerton Lake is just over half full. A little further north, east of Merced, Lake McClure is about 55 percent full, while Don Pedro Reservoir is at 69 percent of its capacity of more than 2 million acre-feet.

And in northern California, the state’s two largest reservoirs are less than half full.

dead tree static chart (2)
The number of dead trees in the mountains of Fresno, Madera, Mariposa and Tulare counties climbed dramatically during the region’s five-year drought before the wet winter of 2016-17. Tim Sheehan tsheehan@fresnobee.com

It’s not so much the current storage in the lakes that’s an issue so much as the relative lack of snowfall in the Sierra Nevada to replenish those lakes next spring and summer. The snowpack is about 20 to 25 percent below normal for this time of year.

It’s a little too early, however, to push the panic button over another drought. While the 2018 calendar year is coming to a close, we’re only a few months into the official “water year” that starts in October and runs through next September.

So while December has been relatively dry in much of California, private weather forecaster Jan Null said January and February can easily make up for the slow start to the rainy season.

“I never panic; it’s way too early,” said Null, who runs a Bay Area consulting firm called Golden Gate Weather Services. “I’ve seen too many miracle Marches. But I’ve also seen it where it goes flat.”

Although Gov. Jerry Brown declared the state’s historic drought officially over in April 2017, dry conditions persist in much of the state. The weekly U.S. Drought Monitor, which is assembled by various federal agencies, says 75 percent of California is in moderate to extreme drought.

Fresno’s most recent rainfall was 0.06 inches on Christmas Eve, and the entire month of December brought only a little over a half inch of rain – nearly an inch less than normal for the month, according to National Weather Service data.

November was a good rainfall month in both Fresno and Merced. Fresno got almost 1.7 inches in the month, beating the November average by six-tenths of an inch, while Merced’s total of 2.36 inches was almost 1.2 inches more than a normal November.

But those months weren’t enough to raise 2018 as a whole to a normal year.

The Fresno River in Oakhurst swells following a storm that dumped heavy rainfall in eastern Madera County in this 2017 file video.

There is also concern for the condition of California’s two most important reservoirs, where much of the water for the state’s two big federal and state water projects is stored. Shasta Lake, the linchpin of the federal Central Valley Project, is just half full, and at 80 percent of historical average for late December. Lake Oroville, which serves the State Water Project, is 29 percent full, and at 47 percent of historical average.

Complicating matters is that the Department of Water Resources plans to run Oroville emptier than usual this winter so it can complete the last of the repairs to Oroville Dam’s flood control spillways. DWR announced in October it plans to keep water levels 13 feet lower than normal to finish the work that’s been under way since 2017, when the two spillways suffered near-disastrous failures.

That 13 feet difference could translate into at least 100,000 acre-feet of water that can’t be stored this winter, possibly reducing supplies available to the State Water Project during the summer and fall. An acre-foot is 326,000 gallons, enough to supply an average California household for one to two years.

The snowpack, which will be surveyed on Jan. 3, plays a crucial role in California’s water health. As it melts during the hot, dry months, water flows into the massive network of reservoirs that ring California’s Central Valley.

They store the water and release it to cities and farms throughout the year. While currently below average, the Sierra snow is better than where it was at the start of this year, when it stood at just 53 percent of average. California’s snow season ended in April at 52 percent of average.

What happens the rest of this season remains unclear. “Right now, I would say the season is in the low normal stage,” Null said.

The Sacramento Bee contributed to this report.

After several dry winters, Fresno and California's San Joaquin Valley hoped for above-average rain and snowfall from an El Niño ocean pattern in the eastern Pacific Ocean in the winter of 2015-16. But that's no guarantee of a wet winter.

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