California Drought, 5 Years Deep with Drastic Changes Between December 2015 and December 2016! (Credit: Meteorologist Jessica Olsen)
DISCUSSION: As 2016 quietly came to an end, we reflect on notable meteorological phenomenon that occurred throughout the year. Of recent observation has been some improvement in the drought monitor for the state of California.
We've attached two US Drought Monitor data sheets showcasing December 29th, 2015 and December 27th, 2016. The differences are quite staggering. California having spent the past 5 years in a significant drought have made conditions for residents challenging. From low-flow toilets, and shower heads to considerable increases in water prices, Californians are feeling the pull on their wallets, land, and agriculture. This goes without saying that reservoir levels have been dire in addition to increased tree death, greater unforeseen fire impacts and decreased snowpack in the Sierra Nevada range.
Reviewing just monthly data we've extrapolated statements of drought intensity. December 29th, 2015 (2015) had clearly been more drought stricken than the month of December 27th, 2016 (2016). In 2015 for D4 classified drought intensity as Exceptional Drought, D4 qualified 44.84% of the California area, whereas 2016 D4 qualified 18.31% of the California area. A drop of nearly 41% in D4 drought intensity compared to that of a year ago.
Of note is author Brad Rippey of the US Department of Agriculture indicating;
"Despite heavy autumn and/or early-winter precipitation nearly region-wide, this season's snowpack remains below average in many California and Southwestern basins, owing to several "warm" storms that have produced more rain than snow. For example, California's Department of Water Resources noted that the average water content of the Sierra Nevada snowpack stood at 6 inches, about 70% of the late-December average but less than one-quarter of the typical April 1 seasonal peak. Still, Western precipitation has been heavy enough in nearly all areas to warrant some improvement in recent weeks, and further improvement could be dictated if strong storms continue to occur and if the USDA's Natural Resources Conservation Service issues and optimistic Western water supply outlook in early January."
As winter has only begun, the National Drought Summary is seemingly more optimistic than traditional forecasts, yet January will remain a month for monitoring. As we anticipate a La Niña pattern it is suspected that precipitation may increase in Northern California while Southern California would experience decreased precipitation. This years' weak La Niña is following one of the strongest El Niño seasons on record, despite normal precipitation in Northern California and below-normal in Southern California.
~Meteorologist Jessica Olsen