Drought Worsens Across the North Bay. Miracle March in the Works?

By February of 2021, following a (so far) dry La Nina winter season, drought had reached moderate to severe conditions across large areas of the state. (Image 2) Moderate to severe drought covered the North Bay.

The numbers tell the story. Santa Rosa and other Northern California stations are far below their average rainfall for the date.

Santa Rosa Normal 24.29in Actual 9.79in Deficit -14.50in
San Francisco Normal 15.94in Actual 6.80in Deficit -9.14in
Oakland Normal 13.35in Actual 5.91 Deficit -7.44
San Jose Normal 9.54in Actual 4.05in Deficit -5.49in
Redding Normal 21.99in Actual 10.49in Deficit -11.50
Sacramento Normal 11.91in Actual 5.36in Deficit -6.55

Snowpack is trending below average as well. For the Sierra as a whole it is 68% of average for the date. (Image 3)

So, is there hope for a wet end to the winter season?

Although it would take a series of giant storms for us to return to normal rainfall, it has happened in past “Miracle March” seasons. In the 2015-2016 season, heavy rains in late February and March brought totals from 60% of normal to 100% in the Napa Valley. (Image 4)

As recently as March of last year, huge storms brought heavy rain and snow to Northern California, boosting rainfall totals and snowpack. (Image 5) Skiers remember this happening right after COVID-19 forced ski resorts to close for the season. (Image 6)

Will something similar happen this year? Perhaps, but the outlook remains uncertain. A few days ago, the well-respected European model issued an outlook for a wet March. (Image 7) So that’s a good sign.

But the CFS model wasn’t as rosy, keeping above normal rain to our north. (Image 8)

Still, the brand new European ensemble model (averaging more than 50 model runs) hedges its bets, keeping us in between wet and dry for most of March. (Images 9 and 10)

So, what does it all mean? Frankly, that forecasters and models alike are split. As the seasons change, big swings in the weather become more likely. And California has a history of wet springs coming after dry winters. But, will it happen this year? It looks 50-50.

Seasonal trends (weakening La Nina, Madden Julian Oscillation, Pacific North American Pattern) seem to suggest something good is brewing. But nailing down the timing and magnitude of rainfall for the North Bay and Northern California is impossible in the long range.

We’ll just have to wait to see how things pan out. And cross our fingers!