Monsoonal showers and thunderstorms brought gusty winds and flash flooding to much of Utah.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SLC wrote it up.
Monsoonal showers and thunderstorms brought gusty winds and flash flooding to much of Utah.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Salt Lake City, UT wrote its last area forecast discussion before the first event at Aug 8, 2:34 PM MST, 3 hours 56 minutes earlier.
Area Forecast Discussion National Weather Service Salt Lake City UT 334 PM MDT Thu Aug 8 2024 .SYNOPSIS...A monsoon surge will bring the threat of heavy rain to central and southern Utah into the weekend. More isolated thunderstorms are expected across northern Utah. && .SHORT TERM (Through 12Z Saturday)...An elongated mid level ridge axis stretches roughly along the Utah/Arizona border this afternoon, as boundary layer moisture has spread into southern and portions of central Utah. Although not particularly rich, ample boundary layer moisture characterized by dew points in the low to mid 50s, along with slow storm motions in proximity to the upper ridge, are supporting convection with occasional deep cores capable of producing heavy rainfall. Given the somewhat limited moisture, this convection is becoming somewhat outflow dominant as it slowly grows upscale and builds off the terrain. Model guidance is in fairly good agreement propagating this activity south- southwest toward Iron/Washington/western Kane counties over the next few hours. Heavy rain/isolated flash flooding as well as the potential for outflow winds in the 40-50 mph range will be the main threats with this activity. This moisture remains in place through Friday, creeping a bit further northward with time. This will bring a chance for afternoon convection up to roughly I-80 during the afternoon/evening. Although moisture content will increase a bit across southern Utah with lower LCLs and slightly higher dew points, the overall flash flood threat will be dependent on lingering overnight/early morning convection and the ability of the airmass to recover. Have maintained "Probable" Flash Flood Potential across most of southern Utah for now, with the potential for greater coverage should the airmass sufficiently destabilize. .LONG TERM (After 12Z Saturday), Issued 440 AM MDT... The period will mainly consist of zonal flow as the jet stream stays positioned across the northern CONUS. High pressure across the southwest and southern CONUS will keep moisture in place for the entire CWA through the weekend and early next week before a drier air mass begins to filter in by the middle of next week. Saturday will be the hottest day of the period, particularly across northern Utah (~5 degrees above normal), before higher moisture advects further north early next week. Saturday and Sunday will pose a flash flood risk across central and southern Utah as PWATs will be near the 90th-95th percentile with ensemble means near 1.3". PWATs will remain elevated across southern Utah, but gradually taper through midweek closer to normal values for this time of year. As such, the flash flood threat will also start to taper. Across northern Utah/SW Wyoming, PWATs peak on Monday with ensemble means ~0.9", which would coincide with the 90th percentile for this time of year. Additionally, an approaching shortwave will lead to more widespread convection. Modest instability on Monday could result in strong to severe convection across northern Utah/SW Wyoming. PWATs lower by midweek closer to climatological normals resulting in less of a flash flood risk. Guidance has started to trend away from a deeper PNW trough for early next week. Instead, ~49% of guidance has a modest trough moving into the Great Basin that could lead to some shortwave ridging ahead of the main passage of the trough by midweek. However, 51% of the members keep more of a zonal pattern with the potential for embedded shortwaves to bring more convection. && .AVIATION...KSLC...Light northwest winds will transition to southeast around 03Z with scattered to broken clouds. Northwest winds are likely by around 19Z. Showers and thunderstorms will likely be to the south, with around a 15% chance for a shower or thunderstorm capable of gusty, erratic outflow winds after 19Z. .REST OF UTAH AND SOUTHWEST WYOMING...Showers and thunderstorms capable of heavy rain, lightning, and gusty, erratic winds will last through around 06Z in southern Utah. Elsewhere, there will be dry conditions with light winds. Scattered showers and thunderstorms capable of heavy rain, lightning, and gusty, erratic winds are likely south of KSLC after 19Z. && .FIRE WEATHER...Monsoon moisture will remain across central and southern Utah through the remainder of the week. This will fuel mainly afternoon and evening showers and thunderstorms capable of producing heavy rainfall. With this moisture in place, daytime RH will remain elevated with good to excellent overnight recovery. Meanwhile, a warmer and drier airmass remains across northern and west central Utah where RH values are in the 10-15% range this afternoon. This warmer and drier airmass will largely remain in place through Friday, with a slight upward trend in RH as moisture to the south begins to creep northward into the area. This will introduce a slight chance for afternoon and evening showers and thunderstorms mainly over the terrain. By Saturday this moisture will have spread across all but far northwest Utah, resulting in a continued upward trend of 5-10% in afternoon RH as well as a better chance for showers and thunderstorms. Southwesterly flow will spread across the region beginning early next week. This will result in a gradual drying trend from west to east as the monsoonal moisture is slowly pushed out of the region. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && Seaman/Wilson/Mahan For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity
Special Weather Statement
National Weather Service Salt Lake City UT
459 PM MDT Thu Aug 8 2024
UTZ122-125-082330-
Southwest Utah UT-Southern Mountains UT-
459 PM MDT Thu Aug 8 2024
...A strong thunderstorm will impact portions of south central Iron
County through 530 PM MDT
...
At 458 PM MDT, Doppler radar was tracking a strong thunderstorm 10
miles west of Cedar City, moving east at 20 mph.
HAZARD...Wind gusts up to 50 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Cedar City, Enoch, Kanarraville, and Hamilton Fort.
This includes the following highways...
Interstate 15 between mile markers 47 and 67.
Utah Route 56 between mile markers 48 and 61.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3756 11331 3777 11330 3778 11298 3753 11308
TIME...MOT...LOC 2258Z 273DEG 19KT 3769 11327
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH
GMSpecial Weather Statement
National Weather Service Salt Lake City UT
529 PM MDT Thu Aug 8 2024
UTZ122-125-090000-
Southwest Utah UT-Southern Mountains UT-
529 PM MDT Thu Aug 8 2024
...A strong thunderstorm will impact portions of south central Iron
County through 600 PM MDT
...
At 529 PM MDT, Doppler radar was tracking a strong thunderstorm 9
miles northeast of New Harmony, or 9 miles southwest of Cedar City,
moving east at 10 mph.
HAZARD...Wind gusts up to 50 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Cedar City, Kanarraville, and Hamilton Fort.
This includes the following highways...
Interstate 15 between mile markers 46 and 59.
Utah Route 56 between mile markers 48 and 54, and between mile
markers 60 and 61.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
&&
LAT...LON 3752 11329 3766 11330 3769 11302 3753 11308
TIME...MOT...LOC 2329Z 265DEG 7KT 3758 11321
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...50 MPH
GMThe Cedar City radar (KICX), 34 km away, was scanning. The volume nearest the first event began at 01:27 UTC.
18 thunderstorm wind, 5 flash flood, 1 strong wind. Local standard time, as filed.
Zion National Park dispatch reported widespread flash flooding within Zion Canyon, including in Behunin Canyon and along the North Fork of the Virgin River.
A roughly 700 cfs flash flood was recorded by the Paria River near Kanab gauge at 12:40 a.m. MDT.
A wind gust of 61 mph was recorded at the UU Portable Trailer 1 mesonet site.
A wind gust of 58 mph was recorded at the 2.5 SW West Point mesonet site.
A wind gust of 58 mph was recorded at the US-89 at MP 406 Weber River mesonet site.
Trees and large branches were downed from a thunderstorm in Woods Cross.
A wind gust of 59 mph was recorded at the I-15 at MP 144 mesonet site.
A wind gust of 59 mph was recorded at the I-80 @ Silver Ck Jct mesonet site.
A wind gust of 62 mph was recorded at the Central Wasatch Peaks - West mesonet site.
A wind gust of 72 mph was recorded at the I-80 at MP 68 West Delle mesonet site.
A wind gust of 65 mph was recorded at the I-80 at MP 71 East Delle mesonet site.
A wind gust of 68 mph was recorded at the Callao Gate mesonet site.
A wind gust of 65 mph was recorded at the Camel Back Mtn mesonet site.
The Emery County Emergency Manager reported around 2 feet of water was observed flowing through Bell Canyon. Time is estimated by archived radar and MRMS data. Exact location is estimated.
A wind gust of 59 mph was recorded at the Hansel Valley mesonet site.
A 38-year-old man drowned Saturday in the waters of the northwest portion of Willard Bay during stormy conditions. This individual attempted to rescue another who went into the water to rescue another who had a life jacket. Nearby wind gusts with an associated outflow boundary ranged from 28 mph (Willard POE RWIS, located just east of Willard Bay) to 32 mph (Great Salt Lake Minerals Site, located just SW of Willard Bay). Small showers with microbursts were also observed in the area, which may have also impacted Willard Bay, in addition to the more consolidated outflow boundary that was moving through the Northern Wasatch Front from south to north during the afternoon.
A wind gust of 61 mph was recorded at the East Bearlake mesonet site.
A wind gust of 64 mph was recorded at the Vernon Hill mesonet site.
A wind gust of 68 mph was recorded at the Cedar Mountain mesonet site.
A wind gust of 69 mph was recorded at the Central Wasatch Peaks - West mesonet site.
A wind gust of 58 mph was recorded at the Carbon County Regional Airport/Buck Davis Field ASOS.
Videos and data showed a flash flood of Wahweap Creek.
The Paria River near Kanab gauge recorded a crest of 830 cfs at 9 a.m. MDT as the peak of the flood wave passed by the gauge.
A wind gust of 59 mph was recorded at the Nephi West mesonet site.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Strong Wind, Eastern Box Elder County | 2024-10-28 | 38 | Male | In Water | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Utah in 2024Every state in 2024This day in weather historyWarnings in Utah, August 2024
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1212919, 1212923, 1214073, 1214074, 1214075, 1214076, 1214077, 1214078, 1214079, 1214081, 1214082, 1214084, 1214085, 1212937, 1214086, 1214170, 1214087, 1214088, 1214089, 1214091, 1214092, 1212951, 1212922, 1214093.