2014-15 rain year ends today in Menlo Park with somewhat surprising results

Those who regularly read InMenlo weather watcher Bill Russ’s rainfall reports, will not be surprised that his back yard gauges recorded 18.1″ for the 2014-15 rain year which began July 1 and ends today (June 30).

Emails Bill: “This compares to 9.55″ in 2013-14; 16.5″ in 2012-13; and 11.95″ for for 2011-12. This, then, was the best of the four years.”

In other weather-related news, Menlo Park-based U.S. Geological Survey recently released a study showing that although record low precipitation has been the main driver of one of the worst droughts in California history, abnormally high temperatures have also played an important role in amplifying its adverse effects.

Experiments with a hydrologic model for the period Oct. 2013-Sept. 2014 showed that if the air temperatures had been cooler, similar to the 1916-2012 average, there would have been an 86% chance that the winter snowpack would have been greater, the spring-summer runoff higher, and the spring-summer soil moisture deficits smaller.

High heat has multiple damaging effects during drought, according to the study, increasing the vulnerability of California’s water resources and agricultural industry. Not only does high heat intensify evaporative stress on soil, it has a powerful effect in reducing snowpack, a key to reliable water supply for the state. In addition to decreased snowpack, higher temperatures can cause the snowpack to melt earlier, dramatically decreasing the amount of water available for agriculture in summer when it is most needed.

Top photo: Rainbow over Menlo-Atherton High School taken in December 2014 by Betsy Sergeant Snow

Middle photo: Drought effects at Trinity Lake, a major California reservoir located about 60 miles NW of Redding, California. USGS photo, Tim Reed, Feb. 2014. Photo source: CA Water Science Center