SALT LAKE CITY (ABC 4) – With mountain snow and frigid temperatures popping up with early-season autumn storms, it’s not uncommon to have winter on your mind in Utah.
We know we struggled through historic drought and we celebrate measurable moisture any given chance here in the Beehive State, and now, our second year La Nina has materialized. The Climate Prediction Center of the National Oceanic and Atmospheric Administration, or NOAA, made the announcement Thursday, October 14th. Forecasters confirm La Nina has developed and will extend through our second winter in a row, as indicated by the ocean and atmospheric conditions over and in the tropical Pacific.
La Nina, translated from Spanish as “little girl,” is one part of the El Nino Southern Oscillation, or ENSO, cycle and is characterized by cooler than average sea surface temperatures near the equator, across the central and eastern Pacific Ocean. Trade winds in the Pacific Ocean bow warmer waters at the surface from South America West toward Indonesia. When this happens, colder water from below the surface rises near the coast of South America. The variable Pacific jet stream typically will stay further North, and the Polar jet stream dips farther east. What does this mean for North America? Well, La Nina is a big driver of what happens in our country and around the world during the late Fall, Winter, and Spring months. It can greatly impact temperature and precipitation.
La Nina winters tend to be drier and warmer across the southern third of the United States, and cooler in the Northern U.S. and Canada. parts of the Midwest, the Ohio/Tennessee Valleys, and the Pacific Northwest tend to see more rain and snow than average. As a result, in Utah, this means Southern Utah has the chance of seeing a drier winter with below-average precipitation chances. The rest of the state has an equal chance to see wetter or drier conditions.
Last year, La Nina brought in below-average precipitation, but there have been years where the top third of the state sees above-average moisture. The other most recent La Nina years in Utah include the seasons of 2008-2009, 2010-2011 and 2016-17, and during those years while most valley locations saw below-normal snowfall, many of our mountain ranges saw the opposite with above-average snowfall years. The Wasatch Mountains also saw one its biggest seasons in 2010-2011 of the last decade, with Alta recording 553″ of snow. After the historic drought, we welcome measurable moisture into Utah. Snowpack helps fill our reservoirs.
This will be our second consecutive La Nina winter, and while that may sound strange, it’s actually not uncommon for forecasters to refer to these conditions as a “double-dip.” You may remember, La Nina developed for the Winter 2020-2021, and held on until April when ENO-neutral conditions returned. On October 21st, NOAA’s Climate Prediction Center will release its temperature and precipitation outlook for the winter. Stay tuned to learn more about the patterns expected.