Following a dry, warm February and moderate precipitation since last October, the statewide snowpack - source of much of the state’s water supply - is only 83% of the March 1 average, the Calfiornia Department of Water Resources (DWR) reported.
“Mother Nature is not living up to predictions by some that a ‘Godzilla’ El Niño would produce much more precipitation than usual this winter,” said DWR Director Mark Cowin. “We need conservation as much as ever.”
DWR recently conducted its third media-oriented snowpack survey of the season 90 miles east of Sacramento just off Highway 50 in the Sierra Nevada. Phillips Station is one of about 250 snow courses measured manually several times each winter.
Frank Gehrke, chief of the California Cooperative Snow Surveys Program, and his survey team measured snow that was 58.3 inches deep at Phillips with a water content of 27.1 inches. The Phillips readings are the best for early March since 2011, but individual snow courses are not generally representative of the entire mountain snowpack.
The statewide readings suggest this may not be a drought-busting year unless California receives heavy rain this month as it did during the “March Miracles” of 1991 and 1995.
“Right now, we’re obviously better than last year but still way below what would be considered adequate for any reasonable level of recovery at this point,” Gehrke said.
Wednesday forecasts from the National Weather Service office in Hanford showed a series of storm ready to hit the Central Valley as well as the Mountain Area, beginning tonight with most rain continuing through the weekend.
By tonight, the NWS forecast showed a 20% chance of rain in Oakhurst around midnight, followed by a slight chance of showers Thursday, with a 50% chance of rain Friday afternoon.
Showers will continue through Saturday into Sunday, meteorologists said, followed by a 70% chance of precipitation Sunday night.
Temperatures will also drop during these storms, from highs of 69 to 75 Wednesday afternoon to highs in the 50s over the weekend.
Outside any oncoming storms or their impacts on snowpack levels, the DWR’s electronic readings of northern Sierra Nevada snow conditions found 23.1 inches of water content 83% of normal for March 1), 212.7 inches in the central region (85% of normal) and 16.6 inches in the southern region (73% of normal).
The snow measurements at Phillips were markedly improved compared to March 2015, when the depth was only 6.5 inches and the water content just 1 inch. Dry conditions persisted in March, and Governor Edmund G. Brown Jr. stood on bare ground on April 1 when he mandated a 25% reduction in water use throughout California.
Traditionally, half of the state’s annual water falls as rain or snow during December, January and February. Precipitation in December and January measured at weather stations monitored electronically by DWR was 170% of the two-month average, but October, November and February rainfall was far below normal. Snowfall since December 1 has mirrored that pattern.
In normal years, the snowpack supplies about 30% of California’s water needs as it melts in the spring and early summer. The greater the snowpack water content, the greater the likelihood California’s reservoirs will receive ample runoff as the snowpack melts to meet the state’s water demand in the summer and fall.
Electronic snowpack readings can be found at cdec.water.ca.gov/cdecapp/snowapp/sweq.action.
Water Year 2016 precipitation is found at cdec.water.ca.gov/snow_rain.html. Look in the right-hand column for the Northern Sierra 8-station index for updated rainfall readings in the critical northern portion of the state, as well as the San Joaquin 5-station and Tulare Basin 6-station links.