A storm on March 31 provided much-needed rain for the San Francisco Bay Area and California, but despite this storm, California’s drought worsened.
Yesterday’s storm dropped .48 inches of rain on my home town of Los Altos, California, a third of the 1.48 inches we received in March (red bar above Mar-14). But the historic average rainfall (blue bar) for March is 2.49 inches, so our March rainfall is an inch below normal and our drought is getting worse.
The cumulative rainfall chart below shows the increasing gap between the historical average and the rainfall we’re receiving.
Notice how the blue line (historic average rainfall) flattens out after March. The dry summer of our Mediterranean climate is approaching, so the chances of significant rain is decreasing.
From this morning’s San Francisco Chronicle, the snowpack in our mountains has much less water than normal.
The best, most reliable measurement of California’s water supply is the Sierra snowpack, which is why surveyors with the California Department of Water Resources go out to calculate the water content.
The Sierra now has an average of only 8 inches of water in the snow, based on measurements from 99 electronic monitoring stations. That’s 29 percent of normal.
California’s reservoirs are already low, and this year’s snowpack will add much less water than in most years.
Our March temperatures were higher than normal, continuing the trend this year.
This warm weather is good news for our fruit trees, which have flowered and set fruit. This young apricot, still wet from last night’s rain, is the size of a small olive.
The State of California and regional water agencies have called for reduced water use. The data shows lower-than-normal rainfall and higher-than-normal temperatures — it seems this would lead to more irrigation, a significant part of our water use.