California-Nevada Drought Status Update

Recent Series of Atmospheric Rivers Alleviate—But Don’t Eliminate—Drought

Key Points

The series of nine atmospheric rivers in December and January helped to alleviate drought in the region. Currently the region is free from exceptional drought (D4), and only 3% of the region is in extreme drought (D3).
The precipitation deficits accumulated over the past 3 years were undone in areas of coastal southern California, central California, and the eastern Sierras in Nevada by the storms of January 2023.
The impacts of the rain and snowfall from December and January were varied throughout the region. Northern and southeastern California and large parts of Nevada didn't get as much precipitation as the central Sierras and central/southern California coasts. Groundwater levels and how much of the snow will run off into reservoirs remain to be determined, leaving the full impact on the drought recovery from these storms still an open question.
The Colorado Basin 24-month study by the Bureau of Reclamation no longer indicates Lake Powell dropping below the power pool, but Lake Mead could drop below 1,000 feet in the summer of 2024 in the minimum probable inflow scenario.

U.S. Drought Monitor Conditions | February 14, 2023

U.S. Drought Monitor

The U.S. Drought Monitor (USDM) is updated each Thursday to show the location and intensity of drought across the country. Drought categories show experts’ assessments of conditions related to dryness and drought including observations of how much water is available in streams, lakes, and soils compared to usual for the same time of year.

California/Nevada conditions as of February 14, 2023:

84.6% of California is experiencing Moderate (D1) to Exceptional (D4) Drought (0% in D3, 0% in D4)
California population in drought: 33,411,791
87.4% of Nevada is experiencing Moderate (D1) to Exceptional (D4) Drought (6.13% in D3, 0% in D4)
Nevada population in drought: 2,602,413

Source(s): NDMC, NOAA, USDA

U.S. Drought Monitor Categories

Last Updated: 02/14/23

85.75%

of California and Nevada are in drought

6.13%

of Nevada is in extreme (D3) drought

of the region is in exceptional (D4) drought

Current Conditions

According to the U.S. Drought Monitor, the series of 9 atmospheric rivers alleviated the drought throughout much of the region with 1–3 class improvements throughout much of California and Nevada. The largest improvements are in Central California and in the Reno/Carson City area.
The impacts of the rain and snowfall from December and January were varied throughout the region. Northern and southeastern California and large parts of Nevada didn't get as much precipitation as the central Sierras and central/southern California coasts. Groundwater levels and how much of the snow will run off into reservoirs remains to be determined, leaving the full impact on the drought recovery from these storms still an open question.
Since the family of atmospheric rivers ended in January, there has been little precipitation throughout the region.
A cooler than average water year has helped to preserve the snowpack and minimize evaporative demand (the “thirst” of the atmosphere).
Snowpack remains well above normal for this time of year—over 200% of normal in many parts of the region.
Western Sierra reservoirs’ reservoir storage plus snowpack is above normal for this time of year. The Northern Sierra reservoir storage + snowpack is near normal while the Southern Sierra reservoir storage + snowpack is ~50% above normal.
In Nevada, reservoirs are at 29% of capacity, which is 80% of the median. Lake Tahoe is above the rim and at 22% of capacity. However, the reservoir storage + snowpack is above normal for this time of year and near the April 1st peak.
Soil moisture in Nevada is near the record maximum, in the 93rd percentile.
The most recent 24-month study for the Colorado River under the minimal probable inflow scenario shows Lake Powellno longer dropping below the power pool, but Lake Mead could drop below 1,000 feet by summer of 2024.
In the Upper Colorado, the combined snowpack and storage of the 20 upstream reservoirs of Lake Powell are slightly above normal for this time of year.
For more information, check out Living with Drought in Nevada and the California Water Watch.

How is drought affecting your neighborhood? Click to see drought indicators, outlooks, and historical conditions by city, county, and state, as well as sign up for alerts.

View local drought information

U.S. Drought Monitor 6-Month Change Map

From August 30, 2022 to February 14, 2023, much of California and Nevada have seen 1 to 3 category improvements on the U.S. Drought Monitor. — U.S. Drought Monitor 24-week (6-month) change map, showing where drought has improved, degraded, or remained the same from August 30, 2022 to February 14, 2023. Source: National Drought Mitigation Center.

Percent of Normal Precipitation: Water Year and Last 30 Days

Since the start of Water Year 2023, precipitation is over 100% of normal for most of California and Nevada, except for the lower southeast corner of the region.

From January 17 to February 15, precipitation has been below normal for most of the region. — Top: Percent of normal precipitation since the start of Water Year 2023 (October 1–February 15). Bottom: Percent of normal precipitation for the past 30 days (January 17–February 15). Source: High Plains Regional Climate Center.

Departure from Normal Temperature: Water Year and Last 30 Days

Since the start of the water year, much of the region is 0 to 4 degrees cooler than normal, with some regions scattered throughout California slightly above normal.

From January 17 to February 15, most of the region has experienced temperatures between 0 and 6 degrees below normal, with the Tahoe region showing even cooler temperatures. — Top: Departure from normal temperature since the start of Water Year 2023 (October 1–February 15). Bottom: Departure from normal temperature for the past 30 days (January 17–February 15). Source: High Plains Regional Climate Center.

Snow Water Equivalent (SWE)

Throughout much of Central and Southern California and Nevada, SWE is still over 200% of normal. In the more northerly regions, SWE is between 175-125%. — Snow water equivalent (SWE) as a percent of the 1991–2020 median recorded by the USDA Natural Resources Conservation Service (NRCS). View an interactive map via NRCS.

Accumulated Precipitation Deficits

For October 2019 to December 2022, the central and coastal southern California precipitation deficits were between <0.5 water year's to >1 water year's worth of precipitation. By February 1, 2023, those deficits had been reduced to zero. Thus, the precipitation deficits over the past three years were undone in this region in January. — Top left: Accumulated precipitation deficits from October 2019 through December 2022 shown in normal water years' worth of precipitation. Top right: Accumulated precipitation in January 2023, represented in normal water years' worth of precipitation. Bottom: Accumulated precipitation deficits from October 2019 through January 2023. Figure provided by M. Dettinger.

Snow Water Equivalent in Nevada and the Eastern Sierra

Current snow water equivalent for Nevada and the Eastern Sierra is in the 93rd percentile, at 182% of the median peak. — Snow water equivalent (inches) for the state of Nevada and the Eastern Sierra. The graph shows the current water year (*black line*) alongside the median (*green line*), minimum (*red line)*, and maximum (*purple line*). Source: USDA Natural Resources Conservation Service.

Water Storage + Snowpack

Water storage (reservoir + snowpack) is near normal reservoir level for this time of year in the Northern Sierra, and increases to almost 50% above normal in the Southern Sierra.

In the Lake Tahoe Basin, snowpack plus reservoir is slightly above normal, although the reservoir remains about two-thirds of normal. — Water storage, a combination of snowpack and reservoir storage, as of February 13, 2023, compared to the 2000–2015 normal for northern California (*top*), central Sierra (*second from top*), and southern Sierra (*third from top*) and compared to 1981–2010 normal for Lake Tahoe (*bottom*). Source: CNAP Water Storage Tracking.

Upper Colorado River Basin Water Storage

Water storage tracking for the Upper Colorado River Basin, upstream of Lake Powell. The reservoir and reservoir+snowpack are about 75% of the April/May peak, and currently just slightly above normal. — Water storage for the Upper Colorado, a combination of snowpack and 20 upstream reservoirs, compared to 1989–2018 normal as of February 13, 2023. Green lines show current (*thick line*) and normal (*thin line*) Lake Powell plus 20 upstream reservoir storage. Red lines show current storage for 20 upstream reservoirs (*thick line*) and reservoirs + snowpack (*thin line*). Source: CNAP Water Storage Tracking.

Drought & Climate Outlook

El Niño–Southern Oscillation (ENSO)

NOAA’s ENSO alert system status is currently a La Niña Advisory. La Niña is expected to transition to ENSO-neutral conditions in the next couple of months. In February–April 2023, there is an 83% chance of ENSO-neutral. For more information, check out the NOAA ENSO blog or current status presentation and how La Niña impacts the Western U.S.

Subseasonal to Seasonal Drought, Temperature, and Precipitation Outlooks

The next 1–3 month forecast shows drought improving or even being removed in northern parts of the region, with drought persisting in central and southern parts of the region. The March outlook from the National Weather Service's Climate Prediction Center predicts below-normal temperatures in the northern part of the region, with equal chances of above- to below-normal temperatures for the southern part of the region. The March precipitation outlook shows a greater likelihood of above-normal precipitation in the northern part of the region. Week three forecasts valid in early March currently do not agree on the sign of atmospheric river activity for the region. More information can be found at the latest CW3E Subseasonal to Seasonal Outlook

Seasonal (3-Month) Drought Outlook

From February 16 to May 31, drought is predicted to persist in southern California and Nevada and either improve or be removed in northern parts of the region. — U.S. seasonal drought outlook, showing where drought is forecasted to persist, improve, be removed, or develop from February 16 to May 31, 2023. Source: NOAA's Climate Prediction Center.

March 2023 Temperature and Precipitation Outlooks

In March 2023, odds favor below-normal temperatures in all but the southernmost parts of California and Nevada.

In March 2023, odds slightly favor above-normal precipitation in northern parts of the region. — Monthly temperature (*top*) and precipitation (*bottom*) outlooks, showing the likelihood of above- or below-normal conditions for March 2023. Source: NOAA's Climate Prediction Center.

Drought Early Warning Resources

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California-Nevada DEWS

Prepared By

Julie Kalansky
Program Manager, California-Nevada Adaptation Program (A NOAA CAP/RISA team)

Special Thanks

This drought status update is issued in partnership between the National Oceanic and Atmospheric Administration (NOAA), the California-Nevada Adaptation Program (a NOAA CAP/RISA team), and the Western Regional Climate Center at the Desert Research Institute to communicate the current state of drought conditions in California-Nevada based on recent conditions and the upcoming forecast. NIDIS and its partners will issue future drought status updates as conditions evolve.