An unusual lack of snow and rain in comparison to past winter seasons has caused concern for western states. The weather from the Sierra Nevada Mountains in California to the Wasatch range in Utah has been warmer and dryer than past years.
According to the BYU Physics and Astronomy Weather Station, the precipitation for December 2011 amounted to 0.03 inches, a far cry from the December 2010 rainfall measured at 5.51 inches.
Bryan Peterson, a professor in the Physics and Astronomy Department, said La Niña is the possible cause of the strange weather.
“Pressure in the Pacific Ocean causes the winds to change and this affects many places in the U.S.,” Peterson said. The reverse of El Niño, La Niña causes months of dry weather and changes how storms move.
Brett Benson, chief meteorologist for KSTU Fox 13, gave another suggestion for the weather in Utah. A ridge of high pressure in the western U.S. changed its location this year. The ridge has been located mainly over the Great Basin causing storms to slide over to the other side of the Rockies.
The effects of the dry conditions are evident throughout the West. According to the National Resource Conservation Service the amount of snowpack in Idaho has not been lower since 1988. The Weather Channel website reported Yosemite National Park opened Tioga Pass on Jan. 4 for the first time since 1933 because of the minimal amount of snow.
California home, farm and business water supply depends on the snowpack from the Sierra Nevada Mountains. Dave Kradz, spokesman for the California Farm Federation, said the state depends on snow melt to fill reservoirs. The water is then directed throughout the state.
“We would like to see some rain and snow,” Kradz said. “We’d all feel better if it storms.”
The greatest concern is for the livestock and cattle owners Kradz said. These ranchers depend on ponds and grasses for their animals. Crop farmers are also in need of water.
“They are already asking for water from irrigation districts,” Kradz said in regard to orchard owners.
Residents may not need to be concerned because of previous winter snowfall. Kradz said the good snow and rainfall from the previous two winters has provided California with enough water in storage.
Over two months of the wet season remains, providing time for storms to increase.
“Strong ridges … can last a few weeks to over a month … but usually don’t last an entire season,” Benson said. He added that a possible change could occur around Jan. 20.