The projected median April-July (AJ) runoff ranges in the major Southern Cascades/Sacramento River basins from 36 percent of average for the Trinity River basin to 58 percent of average for the Pit River basin, in the major San Joaquin River basins from 30 percent of average for the Cosumnes River basin to 61 percent of average for the San Joaquin River basin, and in the major Tulare basins from 23 percent of average for the Tule River basin to 55 percent of average for the Kings River basin.
Since the March 1 B120 was issued, the AJ forecasts for all river basins have decreased significantly (between 6 percent and 10 percent) due to the continued dry conditions and pre-April melt, except for larger decreases on the Feather (14 percent), Yuba (13 percent), and American (19 percent). Since last week’s forecast update, forecasts have dropped between 3 percent and 6 percent, except for that of the American which was decreased by 9 percent.
Since approximately March 15, full natural flow rates have increased due to snowmelt. The increase is more pronounced in the central and southern Sierra. All rivers are running below half of their respective March average rate except the San Joaquin (56 percent). Five rivers (Trinity, Shasta Inflow, Sacramento at Bend Bridge, Cosumnes, and Tule) are flowing at a rate less than 25% of normal for the month.
March remains well below average with none of the three indices recording more than 1.1” of precipitation. After 24 days, the Northern California 8-Station and San Joaquin 5-Station Indices for March are 13% and 17% of an average March, respectively. With the forecast showing no significant precipitation, it is likely that March will conclude a three-month period of well below average precipitation.
Precipitation summary for Water Year 2022 as of March 24, 2022:
The statewide snow water equivalent (SWE) based on snow sensors is 13.3 inches which corresponds to 48 percent of normal for this date. Since March 1, the statewide snowpack has decreased by 2.5 inches, with 2.0 inches melting in the past 7 days.
The regional snowpack levels as of the morning of March 24, 2022 stand at the following (based on snow sensors):
No. of Stations
Percent of April 1
Percent of Normal
Weather and Climate Outlooks:
According to CNRFC 6-day forecast, precipitation is forecasted for Sunday and Monday and will impact the entire state. The central and southern Sierra may see up to one inch of precipitation. The southern Coastal region is forecast to receive the highest totals – most areas up to 1.5 inches and a few areas of the San Gabriel range to receive up to 2.5 inches. Currently freezing levels are between 11,000-12,000 feet in the Northern Basins and at least 12,000 feet farther south. As the front moves across the state on Sunday and Monday freezing levels will drop significantly to 5,000 to 7,000 feet in most areas before returning to between 9,000 and 12,000 feet on Tuesday.
The NWS Climate Prediction Center (CPC) one‐month outlook issued on March 17, 2022, suggests equal chances of above or below normal temperatures throughout the northern half of the state; it suggests above average chances for higher-than-normal temperatures in the southern half. The southern 2/3rds of the state has increased chances for below normal precipitation whereas the northern third has equal chances of above or below normal precipitation.
The CPC three-month (April-May-June) outlook, issued on March 17, 2022, suggests equal chances of above or below normal temperatures for the central coast and northern third of the state; for the rest of the state increased chances of above average temperatures are expected. The outlook also shows equal chances of above or below normal precipitation for the southern half of the state and increased chances of below normal precipitation for the northern half.
According to the latest El Niño/Southern Oscillation (ENSO) discussion issued by the Climate Prediction Center on March 21, 2022, La Niña conditions are present. Equatorial sea surface temperatures (SSTs) are below average across the east-central and eastern Pacific Ocean. The tropical Pacific atmosphere is consistent with La Niña. These conditions are favored to continue into the Northern Hemisphere summer (53 percent chance during June-August 2022), with a 40-50 percent chance of La Niña or ENSO-neutral thereafter.
A Bulletin 120 update forecast for conditions as of March 28, 2022, will be available on Wednesday, March 30th. If you have any questions regarding this forecast, please contact a member of the Snow Surveys and Water Supply Forecasting staff.