- Southern Utah faces resurgent drought and triple-digit temperatures, but relief looms.
- NOAA predicts above-average temperatures and a potentially early, active monsoon season.
- Monsoon storms may bring flash flooding; residents urged to stay informed and prepared.
ST. GEORGE — As southern Utah continues to experience resurgent drought conditions and temperatures reaching up into the triple digits, relief may be on the way, according to weather agencies.
While a recent seasonal outlook from the National Oceanic and Atmospheric Administration predicts that the region will experience above-average temperatures over the summer, it also shows a slightly above-average chance for an early start to an active monsoon season in the St. George area.
"There's more (heat) coming next week, 105 to 110 degrees, across Washington County at the lower elevations, but there is good news in our outlooks, and we are looking for increased monsoonal moisture as we head toward the Fourth of July," said Glen Merrill, a hydrologist for the National Weather Service in Salt Lake City.
Temperatures are predicted to be "near normal" for southern Utah between July 2-8, according to the National Weather Service Climate Prediction Center.
The monsoon season typically runs from mid-to-late July into September in southern Utah. Thanks to a number of factors, the monsoon season may come earlier and bring relief from scorching temperatures, drought conditions or brush fires.
One of the factors that can drive a strong monsoon season is a dry winter. This creates parched soils and can contribute to faster warming of the land, which may stimulate early and vigorous monsoon storms.
"When we have low snowpack years like we experienced this year, and we melt that snow earlier than normal, the landscape is able to warm up faster than normal ... that's one of the factors that goes into monsoonal onset," Merrill said. "The heating of the landscape is what drives the engine of the monsoonal circulation of high pressure. It draws up that moisture from the Baja regions and Gulf of California into the Desert Southwest and eventually into the state of Utah, especially southern Utah."
The heating of the land is just one of many factors that play into the creation of a potentially active monsoon season. Because of those varying factors, predicting how a monsoon season plays out can be tricky.
One of the factors that put an early onset of the monsoon season into question was the ocean temperatures not warming. However, that has changed, and conditions are now aligning with seasonal norms.
Merrill said these temperature changes mean that they will likely "start seeing that moisture come up from the south and into the region."
Long-term weather models are also suggesting the potential for an above-average precipitation season. Several climate models have indicated an above-normal precipitation period for the peak summer months, from late June through August and into early September, Merrill added.
When a monsoon storm does form, it will likely do so in the higher elevations and then move down into the valleys if conditions are right.
"Those storms can actually track from northeast to southwest across Washington County," Merrill said. "We see that a lot ... the heaviest thunderstorms are usually later in the day or in the evening hours in the St. George area."
Monsoonal storms can also be very localized. For example, Hurricane could be hit with a massive storm while St. George only sees a trickle.
"Like 2021, if I'm remembering correctly, the Enoch and Cedar City area just day after day after day, just getting pounded on," Merrill said. "Whereas last year ... areas around that region got pounded on, but they didn't."
While localized storms are a defining trait of monsoon season, there's also the aftermath that Merrill warned about — flash flooding.
"Monsoonal thunderstorms are the type of precipitation events that are the main contributors to flash flooding," he said. "Check the forecast. Educate yourself as much as possible on the potential for heavy rain and have a plan from there."
Flash flooding can be a particular danger in both wilderness and urbanized areas. This is why Zion National Park will close popular hikes like The Narrows following rainstorms.
One of the region's most tragic periods involving flash floods was September 2015, when flooding killed 21 people. This included Hildale residents, hikers in Zion National Park and a Hurricane man who was swept away while on a desert road.
"We certainly never want to repeat that," Merrill said.
