There were gusty winds for different parts of Utah and flash flooding in southern 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.
There were gusty winds for different parts of Utah and flash flooding in southern 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 22, 2:50 AM MST, 3 hours 10 minutes earlier.
Area Forecast Discussion
National Weather Service Salt Lake City UT
350 AM MDT Thu Aug 22 2024
.SYNOPSIS...Almost continuous thunderstorm development across
southern Utah is forecast through Friday resulting from deep
moisture. An area of low pressure from the northwest will
gradually track toward the region, allowing for showers and
thunderstorms across central and northern Utah as well as stronger
winds for Friday. Cooler temperatures will arrive for many
following the passage of a cold front over the weekend.
&&
.SHORT TERM (Through 12Z/6AM Saturday)...
Today into tomorrow is setting up to a little different from the
typical diurnally initiated thunderstorms we might see. That is
not to say thunderstorms won't fire during the afternoon/evening
hours today and Friday, because they certainly will. However,
scattered showers and thunderstorms are expected to almost be
continuously initializing in the south from now through Friday
night. And that does include nighttime convection.
Already in the overnight hours, a few thunderstorms have tracked
across Zion NP and across southwest Utah. An MCV is tracking
through northern Arizona at this hour and is forecast to generally
track northward this morning toward Utah. With an unstable
atmosphere in southwest Utah and potent moisture in place (PW
values of 1.2 to 1.4), continued development of thunderstorms in
southwest and southern Utah is forecast this morning. Some of
these thunderstorms will be capable of producing heavy rain and
localizing flash flooding.
As 1.0+ PW values race their way northward this morning, we'd
only expected additional thunderstorm development to expand in
coverage into central and northern Utah. The moisture in southern
Utah will not go anywhere and as a result, with such potent
moisture in place, a flood watch seems like the right call for
risk of flash flooding in vulnerable areas like slot canyons,
normally dry washes, creeks and streams, recent burn scars, and
other low- lying and flood- prone locations.
All-the-while, an area of low pressure centered to the northwest
will continue to influence our weather headed into Friday. A very
strong pressure gradient will result in strong southerly winds for
the western half of the state, starting very early in the morning
and persisting well into the evening. It may even be tough to get
winds to decrease headed into the overnight hours with winds
still forecast between 25 and 30 mph in the critical layer, ahead
of a cold frontal passage. Winds across the west desert and
southwest Utah, especially along and south of I-80 have a near
100% chance of exceeding 40 mph wind gusts with isolated areas
where 50+mph winds are forecast. As a result, wind advisory
criteria has been considered this forecast package but will let
the day crew make the final decision for tomorrows headlines.
.LONG TERM (After 12Z/6AM Saturday)...An anomalously deep trough
will be moving into the Great Basin on Saturday. Our area will be
ahead of this trough on Saturday with strong southwesterly flow
encompassing the entire area with surface winds gusting 30-40 mph
across most locations Saturday afternoon. Wind gusts 50+ mph will be
possible across higher exposed terrain. This approaching trough will
also help to shift our monsoon moisture further east. High
temperatures on Saturday will be a few degrees below normal as
heights start to fall ahead of the frontal passage. This mostly dry
frontal passage will occur overnight Saturday resulting in
temperatures dropping another ~10 degrees compared to Saturday.
Highs on Sunday will have it feeling like the end of September,
rather than the end of August. Even though drier air will accompany
this trough, any lingering moisture could result in some light
precipitation. There is ~15% chance that the highest terrain of the
Wasatch and Uintas could see their first snowflakes of the season,
but limited moisture will prevent accumulating snow.
This trough will shift east leaving a dry westerly flow in its wake
with temperatures slowly climbing back to near normal by Tuesday.
Guidance starts to diverge by the middle of next week. 53% of
members suggest another trough could graze us to the north and bring
reinforcing cooler than normal air and some precipitation chances.
The other 47% of solutions keep this trough well to the north with
near normal temperatures and dry conditions persisting.
&&
.AVIATION...KSLC...VFR conditions will persist for the KSLC terminal
through the period. Southerly winds will increase through the day
with gusts >20kts during the day. Moisture in place will result in
convection developing near the terminal after ~17Z that could result
in brief MVFR conditions as heavy rain could lead to reduced VIS.
Additionally, outflow boundaries nearby may create brief wind shifts
across the terminal.
.REST OF UTAH AND SOUTHWEST WYOMING...Morning convection
across the far southern airspace will continue through sunrise
resulting in intermittent MVFR conditions from reduced VIS due to
heavy rain. During the day this convection will spread into the
rest of the airspace as monsoon moisture leads to scattered storms
areawide. Strong southerly flow will lead to gusty southerly
winds during the day along with erratic wind gusts and direction
from convective outflow boundaries.
&&
.FIRE WEATHER...Monsoon moisture remains in place for Thursday
with storms along and east of I-15 as a wave moves into southern
Utah from Arizona Thursday morning. Drier conditions will exist
near the Nevada border, but critical RH values will be isolated
and short lived along with southwesterly wind gusts 30-40 mph.
By Friday, this moisture shifts even further east as high
pressure to the southeast shifts further east resulting in a drier
southwesterly flow dominating. Additionally, approaching low
pressure across the PNW will enhance southwesterly winds during
the day on Friday with widespread gusts 30-40 mph along and west
of I-15 with isolated 40-50 mph gusts across more exposed
high terrain. Relative humidity will be near critical along the
Utah/Nevada border with higher RH as you approach the I-15
corridor.
The PNW low will continue to move towards the Great Basin with
winds staying elevated on Saturday and drier air shifting further
east towards the I-15 corridor that could result in isolated areas
of critical fire weather. A cold front will move through late
Saturday into Sunday with temperatures much cooler than normal and
winds relaxing behind the front as they shift to a northerly
direction. RH recoveries will benefit from the cooler conditions.
These improved winds and RH will last into early next week.
&&
.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Fire Weather Watch from Friday afternoon through Friday evening
for UTZ478-492-495.
Flood Watch through this evening for UTZ121-123-124-128>131.
WY...None.
&&
NDeSmet/Mahan
For more information from NOAA's National Weather Service visit...
http://weather.gov/saltlakecityPreliminary Local Storm Report
National Weather Service Salt Lake City UT
608 AM MDT Thu Aug 22 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0552 AM Flood 2 ENE Santa Clara 37.14N 113.62W
08/22/2024 Washington UT Dept of Highways
Street flooding on Snow Canyon Pkwy at Dixie
Downs Road as evidenced on webcam.
&&
NDPreliminary Local Storm Report
National Weather Service Salt Lake City UT
639 AM MDT Thu Aug 22 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0615 AM Rain 1 SSE Ivins 37.16N 113.67W
08/22/2024 M1.50 Inch Washington UT Trained Spotter
&&
NDThe Cedar City radar (KICX), 82 km away, was scanning. The volume nearest the first event began at 12:59 UTC.
7 thunderstorm wind, 4 flash flood, 1 strong wind, 1 hail, 1 flood. Local standard time, as filed.
Snow Canyon State Park reported flash flooding. Campers were displaced from the campsite, multiple waterfalls were observed, and employees had to wait on water to recede at a low water crossing as the flowing water was up to car door handles.
Zion National Park officials reported multiple waterfalls and high flows in multiple slot canyons in Zion Canyon. The North Fork Virgin River near Springdale gauge indicated a spike from 58 cfs to 251 cfs in five minutes, peaking at 264 cfs. Around this time, Zion National Park rangers reported elevated flows and waterfalls in canyons continued. The East Fork Virgin near Glendale gauge peaked at 357 cfs, after starting at 47 cfs.
A wind gust of 61 mph was recorded at the SR-7 at MP 19.5 Sand Hollow mesonet site.
A wind gust of 62 mph was recorded at the Marina mesonet site.
A wind gust of 62 mph was recorded at the I-15 at Willard POE mesonet site.
Six inch diameter limbs were downed from strong winds in Smithfield.
A wind gust of 74 mph was recorded at the Crow Mountain mesonet site.
A wind gust of 60 mph was recorded at the Logan-Cache Airport ASOS.
A wind gust of 63 mph was recorded at the Peter Sinks Rim mesonet site.
Around 430 p.m., three paddleboarders were near the dock at Quail Creek Reservoir when gusty winds pushed them away from the dock. They were not wearing life vests. Two of the people were able to swim back and reach the shore, but a third person was later found unconscious and unresponsive by Quail Creek State Park rangers. The individual, a 50-year-old male, was pronounced dead on the scene. The closest observation, from the White Reef RAWS, indicated southwest winds sustained at 26 mph, gusting to 41 mph at 5 p.m. Note that RAWS report the highest gusts for the previous hour.
A trained spotter reported a large flash flood with water lapping the bottom of the U.S. Highway 89 bridge over the Paria River.
The Dirty Devil Above Poison Springs Near Hanksville gauge peaked at 1052 cfs, likely indicative of flash flooding through most of the slot canyons to the north.
A thunderstorm brought golf ball-sized hail to Helper. The hail covered roads, and plows were used to clear the roads.
The Utah Department of Transportation reported a mud flow up to 2 feet deep across U.S. Highway 191 near milepost 288.
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, Lower Washington County | 2024-08-23 | 50 | 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: 1213535, 1213540, 1214151, 1214152, 1214153, 1214154, 1214155, 1214156, 1214157, 1214327, 1213576, 1213550, 1213556, 1214336.