March this year came is very quietly, if not a bit breezy in the mountains. The high and low temperatures in Bakersfield on March 1st were a few degrees below normal. In Kern County, we have benefited from several weekend storm systems, since the St. Patrick's Day storm, and will end the month a touch above normal for rainfall. That is the first time since October that more than our average monthly tally has fallen. It appears a fast moving storm system will hit the state, with its greatest effect just north of Kern County. No doubt winds will gusts to 70 MPH in the mountains. But then comes April Fools' Day on Sunday, a dramatically cooler day. This will be like going from one season to another, rather than only months.
April Fools' Day originated with an historic change of calendars in the 16th century. The long observed Julian calendar bequeaths the first day of the year as March 25th, in association with the first day of spring. A celebration was held that lasted one week until April 1st. But the Gregorian calendar (which we all use today) was instituted by Pope Gregory XIII in 1582. Not all countries subscribed to it initially. In fact, Britain and all their colonies didn't adopt it until 1752, 170 years later.
As everyone knows, New Year's Day is January 1st. But for all those dolts that still recognized their old fashioned custom of marking March 25-April 1 as the start of a New Year- well, they were worthy of a little derision, especially in France. People used the occasion to play pranks and generally cause mischief aimed at those not willing to progress into the future, either by not recognizing the "modern" Gregorian calendar or simply by not moving to the next year on January 1st.
This Sunday is also a benchmark of things other than mischief for us in California. It is that moment when important measurements are made high in the Sierra. Climatologically, April 1st is considered the time at which snowpacks in the high mountains are as great as they are going to be. Pacific storms hit the high country from late October until early May. But with rising sun angles and rising temperatures, additional heavy snow rapidly becomes less likely after this date.
In years past, such as last winter, the bounty of water content stored in the Sierra snowpack was good news for agriculture, hydrology and the public at large. It meant the coming hot and dry summer (which is a guarantee in California) would have a reliable source of melt water that could carry citizens and growers through until the next rainy season. This year, however, the news is not nearly as rosy. As of this writing, the state average snowpack water content is only 51% of the climatological value. Specifically, the northern Sierra is running at 68% of average, the central Sierra 48% and the southern Sierra only 39%. Even more specifically, those values are 19" (north), 14" (central) and 10" (south), respectively, such that if all were to melt instantly it would be as if that much rain had just fallen in those areas. But, as usually takes place, moisture is released slowly through gradual melting.
This measurement on Sunday will be the basis for rationing water allotments to users of the aqueduct system for irrigation. The amount of runoff from the snowpack affects not only farmers but also recreational enthusiasts who enjoy riding the rapids. There is also the potential danger of flooding in rivers and streams when a heat wave arises during the spring. Runoff affects the vitality of our ecosystem. This year, unfortunately, we will be on the short end of expectations. Hydrologists in Kern County say that it's a good thing we had such a bumper year in 2010-11. Today, we are all still benefiting from all that rain. December 2010 was the wettest year in Bakersfield weather history. It should help take us through this summer, together with the half portion of mountain water we get this year. But if our next rainy season is stingy, we may be in real trouble.