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SALT LAKE CITY — This week just so happens to be monsoon awareness week for the National Weather Service.
It's a week meteorologists use to remind people of how beneficial rains from summer monsoonal storms — prominent in the Southwest — can also result in dangerous situations, including flash, areal or river flooding in slot canyons and in communities. Utahns experienced plenty of this last year when the traditional monsoons returned, resulting in millions of dollars of damage throughout the state.
This year's awareness week will be a little different only because it's forecast to end with some monsoonal moisture a few weeks before these types of patterns typically emerge from the south.
"This is actually a bit early for Utah to this type of moisture," said Christine Kruse, a lead meteorologist with the National Weather Service's Salt Lake City office. "Typically, it's more like the Fourth of July, maybe a little bit later. But this definitely earlier than we've seen the last couple of years."
The storm system moving into the state this weekend is a possible sneak preview of the season to come, which offers good news for the drought-stricken region that's now dealing with raging wildfires.
What to expect this weekend
Hot weather — above 90 degrees across most of the state's communities, including near triple-digit temperatures along the Wasatch Front and mid-100s in St. George — returned Thursday. That's expected to continue through Friday before temperatures slightly cool down the rest of the weekend.
The weather service's Flagstaff, Arizona, office issued an excessive heat warning for the Lake Powell area Thursday, where temperatures may reach up to 105 degrees.
Potential for rain, thunderstorms and microbursts
There are a pair of dueling patterns at play in the West right now that will result in early monsoonal moisture, especially for the eastern half of the state, KSL meteorologist Matt Johnson explains.
Utah is currently in the middle of a low-pressure system in the Pacific Northwest and a hot-pressure system in Texas. As the high-pressure system moves slightly to the east, it's allowing storms to pop up around New Mexico Thursday. Those are expected to expand into Colorado, as well as parts of eastern Utah as early as Friday, Johnson said.
As the low-pressure system moves east, the airflow from the south will continue and the moisture will expand, resulting in more storms in the eastern half of Utah Saturday and Sunday. He added that some of those may even impact Utah's mountain areas during the weekend.
It's not exactly clear how much rain it will produce or if it will result in as much rain as a system that passed through the state a few days ago; however, it does carry the potential for pockets of strong rainfall, according to Kruse.
"There is some potential, if a storm is strong enough, that you could see heavy rainfall — and if it's in the right location Saturday — there could be some concern for flash flooding," she said. "The people who live near recent (wildfire) burn scars should continue to monitor the weather and people who are in slot canyons, dry washes, slick rock areas ... should also pay attention to the forecast."
Thunderstorms are possible across the forecast area Friday and Saturday, bringing the potential for dry microbursts with collapsing storms on Friday, and isolated flash flood potential on Saturday. This is where much of the uncertainty in the forecast remains. (4/4) #utwxpic.twitter.com/800grToBxq— NWS Salt Lake City (@NWSSaltLakeCity) June 15, 2022
She added that lightning and microbursts are also concerns statewide, especially on Friday and Saturday. The moisture is forecast to clear out by the end of Sunday.
Meanwhile, strong winds from the south are also expected as a result of these patterns to either side of Utah, prompting the weather service to issue high wind watches for most of the western parts of Utah that go into effect on Friday. Sustained winds of 35 to 45 mph with gusts in excess of 60 mph are forecast from Wendover to St. George.
"High winds may move loose debris, damage property and cause power outages," the alert states. "Travel could be difficult, especially for high-profile vehicles. Blowing dust may reduce visibility."
Strong winds are expected Saturday and possibly Sunday, too, Kruse added. She said the strong winds are likely what most people will notice more than rain.
This mixture of wind, heat and relative dry humidity before the moisture arrives is why most of the southwest parts of Utah are also listed within another red flag warning. The mixture of the three components makes the region prone to new wildfire starts.
"Critical fire weather conditions" are expected Friday, Saturday and Sunday across central and
Full seven-day forecasts for areas across Utah can be found online at the KSL Weather Center.
A sign for more monsoon rain to come?
This weekend's storm, even if it ends up resulting in not a lot of moisture, could be a sign that the regular summer monsoon patterns will return this year. The first long-range forecasts of the summer months left most of Utah's precipitation outlook in "equal chances," meaning it could be wetter or drier than the seasonal average.
The outlook is improving since that May 19 projection. The weather service's Climate Prediction Center now lists parts of southern Utah within a 33-40% probability of above-normal precipitation totals in July, while the rest of the state is listed in equal chances. The three-month outlook essentially follows this pattern, too.
That's on top of a growing probability for more monsoonal moisture to close out this month.
"It looks like we're starting to see more of a monsoonal pattern develop," Kruse said. "Utah is always on the periphery of the monsoons. It doesn't mean it's going to rain every day or see tons of precipitation, but we are seeing that pattern develop."
She explains that past data indicate that La Nina springs, such was the case this year, lead to normal to below-normal snowpack but it does tend to produce an earlier and "perhaps stronger" monsoon response.
"When we look at these long-range models, you're seeing potentially some of that coming to fruition," she said.
That's good news for Utah, where about 83% of the state remains in either extreme or exceptional drought, according to the U.S. Drought Monitor's latest update Thursday.
The drought has worsened as the result of a dry start to 2022; National Centers for Environmental Information data show that Utah is on pace for its third-driest year since 1895, at least based on the first five months of the year.
About 44% of the entire West is also experiencing those conditions, which is especially true of Arizona, California Nevada and New Mexico. The monsoon forecast stands to drastically help out Arizona and New Mexico, which are where the largest fires are in the region right now.
When it comes to monsoons, experts advise anyone who plans to head outdoors to monitor forecasts this summer, especially if they plan on heading to places with slot canyons and dry washes that are prone to flash flooding. These are common features in and around Utah's national parks and monuments.
Kruse said it's always a good idea to come up with a "Plan B" recreation option on days when a storm is in possibility just to avoid the potential of being caught up in a flood. Flash flooding of 6 inches of water is enough to sweep a person off their feet, weather service officials point out.
Motorists should never drive through flooded roadways, either. The agency says a flood of 2 feet can wash away most cars.
Meanwhile, Kruse recommends that homeowners also monitor forecasts this summer, especially if their properties are near poor drainage areas, dry washes or recent fire burn scars. More tips and flood safety information can be found here.