Some folks have remarked in California that this year was the year of the “No Nino” instead of what was expected to be a strong El Nino in California this year. However, this is only partly true as El Nino did have a big impact on California this winter.
As is sometimes the case, perception ends up as reality, especially if large population centers do not receive the weather they expected. In this case, Southern California did not receive the heavy rains that were expected, although rainfall was much closer to normal than in previous years.
The winter snowpack buildup is critical to California’s water needs. There are three key areas to watch. The chart below shows the southern Sierra Nevada’s snowpack conditions relative to normal as well as to other record years.
As you can see, the Tulare Basin (southern Sierras) is at 94% of normal. This year is far better than the winter of 2014/15 and well ahead of the driest on record in 1976/77. Conversely, this past year has fallen far short of the record El Nino precipitation of 1997/98. Many were expecting amounts this year to be similar to the precipitation that fell in 1997/98. From that standpoint, this past year was quite disappointing for precipitation if compared to 1997/98.
However, as you go further north into central and northern areas of California, El Nino has had a much bigger impact. Some of the largest reservoirs in California are in the northern and central Sierras.
Below is a chart representing snowpack conditions in the Central Sierra Nevada. Snowpack levels are running at 104% of normal (with the chance to add to that this week). Therefore, the central Sierra Nevada has done much better this year, but also far short of 1997/98.
The snowpack story is even better in the northern Sierra Nevada. Some of the biggest water shortage areas reside here and snowpack conditions stood at 120% of normal.
While average precipitation in California will naturally drop in the coming months, there is still a chance that early May could bring California some additional rains and mountain snows.