After summer temperatures in the 90s across norther Utah last week, this week’s weather is expected to be around 10 degrees cooler, the National Weather Service predicts.
Monsoon season is here, meteorologists say, bringing not only temperatures closer to autumn levels but heavy clouds, afternoon showers and possible thunderstorms.
“We’ve seen a push of monsoon moisture, thunderstorms over the past few afternoons, increased cloud cover, and that increased moisture has been moderating our temperatures over the past few days,” meteorologist Brittany Whitlam with the National Weather Service’s Salt Lake City office said Monday.
Some recreation areas around Utah might see flash floods over the next few days, according to the weather service. Flood watches are not in effect yet, but several of Utah’s national parks — Arches, Bryce and Canyonlands — are “expected to experience flash floodings,” Monday and Tuesday, based on the Southern Utah Flash Flood Potential Rating list, which the service’s Salt Lake City office published Monday.
Monsoon season affects the southern parts of Utah from July to September, based on a map published by the federal government’s National Integrated Drought Information System, which monitors rainfall throughout from the Intermountain West through Nevada to California.
The shift in winds caused by the monsoon season in the Pacific, with frequent thunderstorms, and high pressure over the Four Corners area are expected to push moisture north toward southern Utah.
The weather service was expecting thunderstorms on Monday afternoon in some areas, continuing Tuesday and Wednesday, Whitlam said.
“We are looking at thunderstorms this afternoon, tomorrow afternoon and then Wednesday afternoon as well, those all look pretty widespread through that period,” Whitlam said.
In St. George, the chance of rain was set at 30% Monday, rising to 60% by nightfall — and up to a 90% chance of rain by Tuesday. The weather service predicted winds of 6 mph in southwestern Utah on Tuesday, and a high in St. George of 88 degrees (compared with a high of 95 on Monday).
The chance of rain Tuesday in Salt Lake City is at 80%, and could stay there into midweek, the weather service predicted. Low temperatures could drop to 64 degrees in the next two days with calm winds, between 3 and 6 mph.
In North Ogden, the weather service predicted an 80% chance of rain Tuesday and Wednesday, with low temperatures between 61 and 64 degrees.
Forecasters are concerned about a risk of flash floods in areas affected by wildfires — such as the Willard Peak fire that started last week near Ben Lomond. In fire-scarred areas, rocks and land no longer have vegetation that can hold water, so the possibility of flash floods is greater.
“If people live in flood front areas or if they have any outdoor recreational plans, [they should] watch the forecast,” Whitlam said. “If there are any flash flood warnings issued make sure to get to higher ground and never drive through any flood.”
The NWS also offers flood safety tips and resources on their website.