The region has left the drought and its dry days in the past thanks to the above-average amount of rainfall consistently dropping into the Tuolumne River Watershed, and April was no different. The month’s total rainfall nearly doubled the historical average, marking the fifth time this year has exceeded expectations when it comes to recovering from the crippling drought.
During the 2017 precipitation year, which began in September, a total of five months have seen more rainfall than the average recorded in previous years, including October, December, January, February and now, April.
The watershed received 6.35 inches of rain this past month, almost twice the historical average of 3.22, thanks to several storms that rolled through the area on April 8 and 18. Last year, the entire month of April saw just 2.87 inches of rain, while the two stormy days this April yielded over three inches on their own.
In October, the Tuolumne River Watershed received 5.96 inches of precipitation, which was 4 inches more than the historical average. December surpassed its historical average of 5.94 inches as well with 7.62 inches, and both January and February more than doubled their averages.
The wetter months have led to a surplus of water, and to date the watershed has received 62.93 inches of rainfall – 187 percent of the region’s historical average of 33.60 inches for the period between September and April. Last year, the region had received 38.87 inches of rainfall at this point in the precipitation year.
In January, Turlock Irrigation District utility analyst Jason Carkeet cautioned that the extra rainfall could be short-lived, adding that just because the 2017 precipitation year had gotten off to a good start, it did not indicate the rest of the year would be as fortunate.
“In 1997 for example, the September-through-January total for precipitation was 44.55 inches. Nonetheless, the total precipitation for the remainder of the year was only 3.33 inches — nearly 14 inches less than the period mean of 17.05 inches,” said Carkeet at the time.
Now, the additional rainfall has continued to pour and is not only above average, but record breaking.
“This has been an anomalous year,” Carkeet said Tuesday. “Although total watershed precipitation is expected to be just under the highest value on record, watershed runoff is expected to set a new annual maximum with yield at or above 4.6 million acre-feet.”
Although the May weather has so far been warm and sunny, the trend of rainy weather is expected to continue this month as there is a 60 percent chance of rain this weekend.