NASA researchers have developed new satellite-based, weekly global maps of soil moisture and groundwater wetness conditions and one to three-month U.S. forecasts of each product. While maps of current dry/wet conditions for the United States have been available since 2012, this is the first time they have been available globally.
Snow has finally diminished a bit after California’s Sierra Nevada picked up several feet of snow, part of a “Miracle March” weather pattern helping to replenish vital, water-providing snowpack after a record-dry February.
Heavy snow began in the Sierra last Saturday and continued through Monday night leading to major travel headaches.
Monday night, a section of Interstate 80 westbound near the California-Nevada state line was closed due to multiple spinouts.
The most recent U.S. Drought Monitor data, released Thursday, show that about 48% of California is in moderate drought. That’s up from 34% a week ago.
An additional 30% of the state is abnormally dry, according to the data.
The data were compiled Tuesday, so the figures do not reflect moisture from Southern California’s most recent storm.
As California approaches what could be another drought, water utilities are eager to find new ways of curbing water demand. Stanford researchers have developed a machine learning model that detects unexpected water-use consumption patterns – data water utilities can use to inform resource planning and water conservation campaigns.
February has been amazingly dry in California, if anyone hasn’t noticed. No precipitation at all in February, a dry forecast, about 51% of seasonal Sacramento Valley precipitation (a bit less for the San Joaquin and Tulare basins), and only about half (45-57%) of normal snowpack for this time of year. Unless March is wet, this dry year seems likely to advance the onset of the fire season and threaten forest health this year.
Reservoir levels are still not bad for this time of year. Many are fuller than average, perhaps reflecting some snowpack loss. Some other reservoirs are a bit low. This is inherent in the first year of a drought, low precipitation and snowpack, but mostly ok reservoirs.
Groundwater has recovered somewhat from the previous 2012-2016 drought, better in the north, but less in the state’s more overdraft-prone areas in the San Joaquin and Tulare basins.
Some communities in California just experienced the driest February ever, and there’s around an 80 percent chance the state will enter a full-blown drought this year.
If that happens, it could be the third-driest year in over a century, according to modeling by the Center for Watershed Sciences at UC Davis.
But even though around a quarter of California is undergoing moderate drought conditions experts say it’s too early to panic — they say a second year of drought is where things get dicey.
“The first year of a drought is really mostly a wake-up call,” said Jay Lund, the center’s director. “It will be prudent, if this turns out to be a dry year, for us to prepare for it to be a longer drought.”
After a wet and snowy start, California’s winter has gone bust. The 2019-2020 water year started off with robust precipitation after a series of storms in November and early December 2019.
But the new year has not been as bountiful. Dry conditions in January and February added little to the Sierra Nevada snowpack.
Left: 2019, Right: 2020. Sierra Nevada snowpack is below normal for this time of year, at about 58% statewide. Graphic: NASA/National Weather Service via NWS Sacramento
Due to California’s climatological variability, including periods of drought, the Water Authority and its 24 member agencies have diversified water supply sources. Those successful efforts ensure supply reliability for the region’s 3.3 million residents and its $245 billion regional economy.
“Based on current supply levels, the Water Authority and its 24 member agencies will meet anticipated demands through a combination of drought-resilient local and regional water resources,” said Goldy Herbon, Water Authority senior water resources specialist.
Herbon said the Claude “Bud” Lewis Carlsbad Desalination Plant, conserved agricultural water transfers, savings from canal lining projects and continued water-use efficiency measures are among the reasons the region’s water supply will meet demand.
The multi-decade water supply diversification plan, along with major infrastructure improvements and forward-thinking policies, also promote fiscal and environmental responsibility.
“A comparison of the snowpack across the Sierra-Cascade range over the past 6 years shows the true variability of a California wet season. While numbers are similar to the 2017-2018 winter, snow did extend into somewhat lower elevations back then.” NWS Sacramento, February 26, 2020
While rainfall totals have been closer to average in most of Northern California, downtown Sacramento and downtown San Francisco did not receive any precipitation in February, according to the National Weather Service. The last time San Francisco saw a dry February was in 1864, according to the NWS.
February 2020 was the driest on record for the northern Sierra (8-station index)! Observed precip was 0.2 inches compared to the average of 8.2 inches. Data courtesy of @CA_DWR #cawx #cawater pic.twitter.com/PJMD7u2Uuu
— NWS California-Nevada RFC (@NWSCNRFC) March 1, 2020
Southern California is faring better, with rainfall at 125% of the historical average at Lindbergh Field in San Diego.
Most major California reservoirs are at or above the historical averages for late-February.
The state’s largest six reservoirs currently hold between 92% (Oroville) and 132% (Melones) of their historical averages for February 26. Lake Shasta, California’s largest surface reservoir, is 107% of its historical average and sits at 78% of capacity, according to the California Department of Water Resources.
California’s largest six reservoirs hold between 92% and 132% of their historical averages for Feb. 27. Lake Shasta, California’s largest surface reservoir, is at 107% of its historical average and is at 78% of capacity. Graphic: California Department of Water Resources
The Department of Water Resources February 27 conducted the third manual snow survey of 2020 at Phillips Station. The manual survey recorded 29 inches of snow depth and a snow water equivalent of 11.5 inches, which is 47% of the March average for this location, according to a DWR news release. The snow water equivalent measures the amount of water contained in the snowpack, which provides a more accurate forecast of spring runoff.
“Right now, 2020 is on track to be a below-average year but we could still see large storms in March and April that will improve the current snowpack,” said Sean de Guzman, chief of DWR’s Snow Surveys and Water Supply Forecasting Section. “While periods of dry conditions are expected in California, climate change has made them more unpredictable and extreme which is why we must always use the water we have wisely.”
The seasonal outlook for March, April, and May sees below-normal chances for a wet period across California and the Southwest U.S. while most areas are favored to be warmer than usual. Graphic: National Weather Service Climate Prediction Center
Looking ahead, the National Weather Service Climate Prediction Center forecast favors above-normal temperatures and below-normal precipitation through May for most of California.
The National Weather Service Climate Prediction Center forecast favors above-normal temperatures and below normal precipitation through May for most of California. Graphic: National Weather Service Climate Prediction Center
A winter with little precipitation has left most of California abnormally dry and officials are bracing for the possibility of an early and more intense wildfire season amid record-breaking temperatures.
Drought has expanded to nearly a quarter of the state, mainly in central California, the heart of the state’s agricultural sector, according to a U.S. Drought Monitor map mad public Thursday. The map shows 70 percent of the state is abnormally dry.
The latest U.S. Drought Monitor map released Thursday shows that 9.5% of California is considered to be in moderate drought. The abnormally dry area, which includes the drought area, has expanded from about 34% to 46%.
The dry area on the new map has spread southward to include most of Los Angeles County, much of Kern and San Luis Obispo counties and all of Santa Barbara and Ventura counties.
This rain-year has brought an alarmingly dry winter in California so far, according to climate change experts.
Now, there’s a new tool to help Californians navigate your water supply. It’s an online toll that allows a person to see the groundwater levels in their area. The tool then gives a representation of what could be at risk or impacted if a drought hits.
