Despite lackluster numbers so far in January, the Tuolumne River Watershed received more than enough rainfall in December for the Turlock Irrigation District to feel optimistic that precipitation numbers could end up above average by the month’s end.
December storms proved to be incredibly productive within the watershed, according to TID hydrologist Olivia Cramer, dumping 11.4 inches of rainfall throughout the course of 31 days. Cramer informed the TID Board of Directors during their Tuesday meeting that 11.4 inches is well above the month’s average of 5.86 inches, nearly doubling the amount of rainfall the area has seen historically.
This month, however, has been far below average when it comes to precipitation. Though the month is halfway over, January has received just 0.04 inches of rainfall compared to the 6.5-inch average. Despite this, the ample amount of rainfall in December still puts the watershed at 129.5% of the historical average through Jan. 11 with a total of 18.76 inches since Sept. 1.
Historically, the watershed has received an average of 19.1 inches by the end of January.
“Moving forward, if we do not receive precipitation from now to the beginning of February, we will end up back to below average conditions,” Cramer said.
Looking optimistically at things, Cramer added, should TID’s “average” rainfall projections play out by the end of the month, the scenario would then be above the historical average.
“Which is a good sign,” she said. “Once we see that dropping below that value, we start to have some concern over the overall precipitation year accumulations.”
The 2021-2022 water year has already surpassed last year in terms of precipitation and substantially boosted the snowpack, which now sits at 125.8% of average for the date. There’s still a way to go, Cramer noted, as the snowpack numbers are just 55% of what they should be by April 1, when peak snowpack levels are reached.
The storms also benefited soil moisture, which helps all of that snow stay in the mountains longer. The current soil moisture sits at about 550,000-acre feet, which is about a 20% exceedance and well above average for this time of year. The snow water equivalent of the snowpack is around 580,000-acre feet, also above average.
The large snowpack has helped California dodge the worst of its drought conditions according to information released by the U.S. Drought Monitor on Thursday, which showed the state is officially out of the “exceptional drought” category.
Three months ago, nearly 46% of California was classified as the exceptional drought category, or D4, which is the most extreme level of drought on the monitor. Last week that number had improved 0.84%, and now there are no places in the state experiencing exceptional drought.
The state isn’t out of the woods yet, though. Only about 1.4% of the state is now considered the D3 category, extreme drought, compared to 16.6% last week and about 87% three months ago. However, 100% of the state is still experiencing some sort of drought with 64.99% in the D2, or severe drought, category.
To view the U.S. Drought Monitor, visit https://droughtmonitor.unl.edu/