Photo: The California Department of Water Resources’ Frank Gehrke (left) talking with reporters while measuring the depth and water content of the snow on February 1, 2018.

 

“Hoping for a March Miracle to bail out California’s dry winter? It’s not likely,” says today’s issue of the San Jose Mercury News. They analyzed more than 100 years of rainfall records of the major cities in California, including San Diego, and the data showed, “That none have ever finished the rainy season with normal rainfall totals after ending January with the amount of rain they’ve had so far this winter.”

The good news is that most of California’s reservoirs are full — of last year’s record-breaking statewide precipitation.  One exception, however, is Lake Oroville, which is at just 41 percent of capacity. Lake Oroville is the water supply for the State Water Project, which transports water from the northern Sierra to Southern California. Note, too, that Lake Cuyamaca, Helix’s reservoir in our local mountains, is nearly empty.

61%

Snowpack
Upper Colorado River Basin
(% of avg. for this date)

22%

Snowpack
Northern Sierra
(% of avg. for this date)

5.36"

Precipitation
Lake Cuyamaca
(Dec 2017 – Jan 2018)

41%

Reservoir Level
Lake Mead
(% Full)

41%

Reservoir Level
Lake Oroville
State Water Project
(% Full)

7%

Reservoir Level
Lake Cuyamaca
(% Full)

What’s causing warm, dry weather across the state? The Ridiculously Resilient Ridge — that high pressure ridge that forms over the eastern Pacific Ocean and western U.S. and remains in place for weeks, or months (see image below). The ridge was the primary cause of California’s five year drought. Stanford University’s Daniel Swain wrote on February 1 that the ridge will “probably stick around for the foreseeable future (certainly for the next 10 days, and plausibly for the next 2-3 weeks).”

Below: The Ridiculously Resilient Ridge (Feb 1 2018)

Take a look at the U.S. Drought Monitor map below. Moderate to severe drought conditions are pervasive across central and southern California, and across the Colorado River Basin.