Utah’s water year begins in October.
Utah Snow Survey Data Collection Officer Jordan Clayton said starting in the fall better encapsulates when the state receives water and when it flows into reservoirs.
“We obviously get most of our water from our snowpack, which accumulates more or less starting in October, and then we see all that runoff into the spring,” he said on KPCW’s “Local News Hour” Oct. 22. “Of course the summer monsoon is useful as well.”
Most of Utah’s water comes from the snowpack, so in low snow years, water officials expect a low water year. This past winter, snowpack peaked nearly a month early and at record poor levels.
Clayton said that is despite some high precipitation months.
“We did have excellent precipitation, particularly in the summer monsoon. Also, last October was pretty wet,” he said. “So we ended the water year strong from a precipitation perspective.”
The rains help with soil moisture, which allows for snow runoff to flow into Utah’s reservoirs and reduces wildfire risks.
Clayton said monsoonal storms increase soil moisture if precipitation continues after the initial storms.
“That's one of the problems that we had last season: we got really nice precipitation in October, and then things started to dry out before the snow really started to accumulate in November and December,” he said.
Now, soil moisture in the mountain is well above normal in many areas. Clayton said the October rain is important and officials expect soil moisture to be normal or above normal going into winter.
The Climate Prediction Center is forecasting a Super El Niño season, and Clayton said the models for Utah are encouraging starting in January.
“The three month prediction windows that you can get from the Climate Prediction Center show elevated chances of above-normal precipitation for Utah during those kind of midwinter to early spring months, so that's encouraging.”
Clayton said Super El Niño patterns can be a hit or miss for Utah. In 1983 Utah recorded a historically high snowpack. He said 2016 was also a Super El Niño which brought snow to some areas and below normal for others.
