Deep snowpack + forecast hot weather could = flooding in northern Utah

(Trent Nelson | The Salt Lake Tribune) Cyclists along the Jordan River Parkway in South Salt Lake on Thursday May 30, 2019. Remaining snowpack and expected high temperatures in the 80s next week could spell flooding.

Utah rivers are expected to swell dangerously in the coming weeks as warm weather melts snow into fast flowing, frigid runoff.

Major flooding is not anticipated, but the rise in water levels will be steeper than past years because of an unusually wet and cold spring, according to the National Weather Service. Utahns recreating or working near rivers, especially those fed by high elevation snowmelt, should exercise extra caution in the coming weeks.

This year is the second wettest recorded spring on record in Salt Lake City with 11 inches of precipitation so far, according to the weather service.

Although Salt Lake City had more snowpack volume in 2011, the wettest spring on record, weather remained cool later into the summer causing causing the snowmelt to “peter out” slowly, National Weather Service hydrologist Brian McInerney said in a video released Wednesday. Temperatures in 2019 have remained low through May, preserving much of the snowpack, but are expected to rise into the 80s next week. With a jump in temperatures will come a rapid rise in Utah waterways including the Big and Little Cottonwood canyon rivers, the Provo River and the Weber River.

(Christopher Cherrington | The Salt Lake Tribune)

In an interview with the Tribune, McInerney said the weather service can only forecast daily weather seven days in advance, but current trends suggest the rivers will swell each day for the first two weeks of June, or as long as snow is melting. He expects rivers to begin to decrease in size around the third week of June as Utah runs out of snowmelt.

On Thursday, the Bureau of Reclamation sent out a news release stating that it will increase flows from the Flaming Gorge Dam on the Green River starting on June 3. The Bureau said the decision to increase flows was made based on a number of factors including river and reservoir conditions, projected snowmelt and current weather forecasts. The news release advised caution to anyone working or recreating on the Green River near the dam because the river will be swift and cold.

Rivers flush with snowmelt are especially frigid and can send people into hypothermia within minutes, said McInerney. When this happens, people’s ability to use their limbs to swim or pull themselves out is diminished and they become helpless in the strong river currents.

Those enjoying the mountains in the coming weeks should avoid rivers and pay extra attention to pets and children to prevent them from falling in, advised McInerney. He said dogs will sometimes jump into rivers chasing balls or sticks and become caught in the strong currents. If this happens, dog owners should not attempt to enter the river to help their pet as such a rescue attempt can end tragically, said McInerney.

Children are particularly at risk since they do not understand the dangers of rivers and are attracted to water, said Unified Fire Authority spokesman Matthew McFarland. Small children can be swept away in a matter of seconds.

“We implore people to watch pets and children,” said McFarland, who cautioned that just 4 inches of fast-moving water can be enough to sweep a person away.

Should a person or animal fall into the water, onlookers should not jump in after them as would-be rescuers often become secondary victims, McFarland said. Instead, one person should try to keep pace with the victim from the riverbank while someone else calls 911.

For anyone being swept away by a river, the best thing to do is to attempt to keep one’s feet pointed downstream and above water to avoid getting caught on underwater debris, McFarland said. A person should then attempt to use their arms to guide themselves into shallow water.

The bright side? After experiencing record-breaking dry weather last year, Utah is currently drought free, McInerney said, and should have a good supply of water for the next year.