Alert archive / Utah / Severe Thunderstorm Warnings in 2024

Severe Thunderstorm Warning 81, NWS Salt Lake City, UT

August 19, 2024Juab County, Utah County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 19, 2024, 5:40 PM MDT for Juab County, Utah County, Utah. It was in force for 35 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 19, 2024, 5:40 PM MDT (23:40 UTC)
Expired
Aug 19, 2024, 6:15 PM MDT
In force
35 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Juab County, UT, Utah County, UT

The radar

The Salt Lake City radar (KMTX), 151 km from the middle of the area, began a volume at 23:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Grand Junction, CO (KGJT), launched 12:00Z, 11.7 hours before the alert went out and 331 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Grand Junction, CO at 12:00Z on 2024-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2024-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
13 J/kg
Mixed-layer CIN
-237 J/kg
Mixed-layer LCL
1747 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
117 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Aug 19, 3:54 PM MDT, 1 hour 46 minutes earlier.

Area forecast discussion, Aug 19, 3:54 PM MDT, 1 hour 46 minutes before
Area Forecast Discussion
National Weather Service Salt Lake City UT
354 PM MDT Mon Aug 19 2024

.SYNOPSIS...A drier airmass will gradually spread into the area
through Tuesday. Another monsoon surge is expected Wednesday into
the end of the week.

&&

.SHORT TERM (Through 12Z Wednesday)...The persistent upper level
ridge remains in place across the Four Corners region. Moist,
southwest flow continues across the western periphery, though
precipitable water values have fallen over yesterday's values, now
around 125-150% of normal, rather than 150-200% of normal.

With SBCAPE values near 1000-2000 J/kg per latest mesoanalysis
juxtaposed over deep layer shear near 35-40kts or so across much
of northern and central Utah...organized convection remains
possible into the evening. A few storms will be capable of strong
winds, small hail and of course heavy rain.

The ridge will flatten slightly Tuesday...bringing even drier air
into much of the state and suppressing the threat of heavy rain to
the far south. This will be temporary however...as PWs once again
surge to 125-150% of normal, mainly east of I-15, by 12Z Wednesday.

.LONG TERM (After 12Z Wednesday), Issued 428 AM MDT... At the
beginning on the long-term period, Utah will be in broad
southwesterly flow ahead of mean troughing over the northwestern
US, with a strengthening closed low moving southward along the BC
coast. This low is likely to move inland into the northern Great
Basin, bringing a transition to cooler, drier weather this weekend
as it slides just to our northwest.

But for now, persistent monsoonal moisture is expected through at
least Friday, mainly across southern and eastern Utah. Thus, a
heightened flash flood risk is expected for prone areas near slot
canyons and areas near recent burn scars. Areas north of roughly
Beaver County and west of I-15 may see isolated thunderstorms at
best.

As the closed low pushes inland late in the work week, southwesterly
winds will increase, especially across western Utah where ensemble
mean wind gusts are currently around 40-50mph on Friday. Combined
with low RH across western valleys, we will need to keep a close eye
on the possibility of critical fire weather conditions. Across
eastern areas, showers and thunderstorms may become a bit more
organized on Thursday and Friday as shear increases ahead of the
low, but details are still unclear.

Uncertainties still remain in the exact timing and track of the low,
however model guidance suggests a quick transition to cooler and
much drier weather on Saturday...especially across northern areas.
Current ensemble means for 700-mb temperatures are more akin to mid
to late September climatologically...though plenty of spread
remains, ultimately depending on the track of that low pressure
system.

&&

.AVIATION...KSLC...There is a roughly 20% chance for showers and
thunderstorms capable of gusty, erratic outflow winds, and locally
heavy rain through 03Z. Gusty southeast winds will prevail
through 03Z, but outflow winds could alter speed and direction.
Clouds will clear with light southeast winds through the night.

.REST OF UTAH AND SOUTHWEST WYOMING...There is roughly a 20% chance
for showers and thunderstorms capable of gusty, erratic outflow
winds and locally heavy rain through 03Z for southwest Wyoming and
northern Utah. Largely dry conditions are likely throughout southern
Utah. Clouds will diminish throughout southwest Wyoming and Utah for
overnight, with isolated showers and thunderstorms for southwest
Wyoming and eastern Utah by around 19Z.

&&

.FIRE WEATHER...The current monsoon surge will wane
Tuesday...with less coverage of showers and thunderstorms. Dry
southwesterly flow will bring localized critical fire weather
conditions west of I-15 Wednesday through Friday, with another
monsoon surge for areas east of I-15.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

Kruse/Cunningham/Wilson

For more information from NOAA's National Weather Service visit...
http://weather.gov/saltlakecity

In the hours before

Special weather statement, Aug 19, 4:14 PM MDT, 1 hour 26 minutes before
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Special weather statement, Aug 19, 4:31 PM MDT, 1 hour 9 minutes before
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Special weather statement, Aug 19, 4:49 PM MDT, 51 minutes before
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Special weather statement, Aug 19, 4:59 PM MDT, 41 minutes before
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Special weather statement, Aug 19, 5:31 PM MDT, 9 minutes before
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The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 18, 6:07 PM MDTSpecial Weather StatementSLCRich38 min
Aug 18, 6:16 PM MDTSevere Thunderstorm WarningSLCBox Elder44 min
Aug 18, 6:28 PM MDTSevere Thunderstorm WarningSLCBox Elder47 min
Aug 18, 7:00 PM MDTSevere Thunderstorm WarningSLCBox Elder45 min
Aug 18, 7:14 PM MDTSpecial Weather StatementSLCBox Elder31 min
Aug 18, 7:50 PM MDTSpecial Weather StatementSLCBox Elder40 min
Aug 19, 2:14 PM MDTSpecial Weather StatementSLCDavis31 min
Aug 19, 2:45 PM MDTSpecial Weather StatementSLCDavis30 min
Aug 19, 3:44 PM MDTSpecial Weather StatementSLCEmery31 min
Aug 19, 3:59 PM MDTFlash Flood Warning Considerable damage threatSLCWayne3 hr
Aug 19, 4:14 PM MDTSpecial Weather StatementSLCEmery31 min
Aug 19, 4:19 PM MDTSpecial Weather StatementSLCEmery26 min
Aug 19, 4:31 PM MDTSpecial Weather StatementSLCWayne29 min
Aug 19, 4:49 PM MDTSpecial Weather StatementSLCEmery26 min
Aug 19, 4:59 PM MDTSpecial Weather StatementSLCCarbon31 min
Aug 19, 5:31 PM MDTSpecial Weather StatementSLCSanpete29 min

Nearby

Severe Thunderstorm Warnings in Utah, 2024Every severe thunderstorm warning in 2024

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.