California's Wet Season Hasn't Brought Much Drought Relief and the Outlook Isn't Promising

 Linda Lam

Published: February 22, 2021

California's wet season has not brought much relief so far and the outlook is not promising.

The water year, which runs from October through April, started off slowly. October was the second driest on record for California. Later, strong systems – including an atmospheric river in late January that caused flooding, debris flows and feet of snow in the Sierra – brought needed moisture to the Golden State.

(MORE: California Atmospheric River Triggered Flooding, Feet of Snow)

The small areas of green on the map below show where the atmospheric river stalled and resulted in above average precipitation from Oct. 1, 2020 through Feb. 18, 2021. But most of the state is much drier than average for the wet season so far.

Areas in brown have seen less precipitation than average since October 2020.

San Francisco, Sacramento, Los Angeles and San Diego are among the many cities that have seen less than half of their average precipitation since Oct. 1.

Drought expanded and worsened across California late last year. The improvement has come since the beginning of the year, according to the U.S. Drought Monitor.

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Just under 58% of the state was in severe drought Feb. 16 compared to just over 74% on Jan. 5.

However, 99% of California is still at least abnormally dry. Just a small corner in the far northwestern part of the state is not because of stormy pattern there.

Drought changes from Jan. 5, 2021 to Feb. 16, 2021.

The late January storm also helped the snowpack in the Sierra Nevada mountains. But since then, snowfall has not been as abundant. This has caused the percent to average for snow water equivalents in the Sierra to decrease, according to the California Department of Water Resources.

The central Sierra is closest to where it should be for this time of year for water content in the snowpack at 75% of average. The southern Sierra is just about half of average for mid-February and the Sierra Nevada snowpack across the state is about two-thirds of average.

Mountain snow is important in the West. Snowmelt is crucial to California's water supply because it recharges reservoirs and rivers downstream during the dry summer and early fall.

Numbers indicate the percent to average for Feb. 18 for how much water is contained in the snowpack.

Any Help Ahead?

California receives most of its precipitation during the winter and early spring. If this doesn't happen it raises risks for wildfires and water availability in the summer and fall.

Last year, California saw its largest wildfire on record in August and wildfires burned more than twice the state's previous record.

This time last year, less than 10% of the state was in drought. So a much wetter pattern needs to emerge soon to put the state in better shape heading into the dry season.

Unfortunately, the outlook is not promising. Little to no precipitation is expected through the end of February.

(MAPS: 7-Day Forecast)

California, with the exception of far northern areas, will likely experience drier than average conditions during the March through May period, according to NOAA. Above-average temperatures are also anticipated for the southern half of the state this spring.

This outlook is driven in large part by the La Niña event that will transition into ENSO-neutral conditions into the spring. La Niña typically results in drier than average conditions across the southern tier of the U.S., including Southern California.

Drought conditions are expected to persist through the end of May and possibly intensify in some locations, according to the latest outlook from NOAA.

Areas in brown are expected to remain in drought through the spring.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.