Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 30, NWS Salt Lake City, UT

July 24, 2021Washington County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 24, 2021, 3:16 PM MDT for Washington County, Utah. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 24, 2021, 3:16 PM MDT (21:16 UTC)
Expired
Jul 24, 2021, 3:45 PM MDT
In force
29 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Washington County, UT

The radar

The Cedar City radar (KICX), 60 km from the middle of the area, began a volume at 21:20 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

Las Vegas, NV (KVEF), launched 12:00Z, 9.3 hours before the alert went out and 213 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, Las Vegas, NV at 12:00Z on 2021-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 335 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2021-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.1939Sfc1 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
335 J/kg
Mixed-layer CIN
-191 J/kg
Mixed-layer LCL
2063 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

840 
WUUS55 KSLC 242116
SVRSLC
UTC053-242145-
/O.NEW.KSLC.SV.W.0030.210724T2116Z-210724T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
316 PM MDT Sat Jul 24 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Central Washington County in southwestern Utah...

* Until 345 PM MDT

* At 315 PM MDT, a severe thunderstorm was located 11 miles 
  southwest of New Harmony, or 28 miles west of Zion National Park, 
  and is nearly stationary.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Washington, Hurricane, New Harmony, Quail Creek State Park, Ivins,
  Toquerville, Leeds, Pine Valley and Snow Canyon State Park.

This includes the following highways...
 Interstate 15 between mile markers 18 and 25.
 Utah Route 18 between mile markers 9 and 15.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3717 11335 3719 11367 3752 11360 3750 11326
TIME...MOT...LOC 2115Z 183DEG 7KT 3736 11345 

HAIL...1.00IN
WIND...60MPH
 
$$

ND
1 follow-up statement
088 
WWUS55 KSLC 242131
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
331 PM MDT Sat Jul 24 2021

UTC053-242145-
/O.CON.KSLC.SV.W.0030.000000T0000Z-210724T2145Z/
Washington UT-
331 PM MDT Sat Jul 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM MDT
FOR CENTRAL WASHINGTON COUNTY...

At 331 PM MDT, a severe thunderstorm was located 9 miles southwest of
New Harmony, or 28 miles southwest of Cedar City, moving north at 10
mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Washington, Hurricane, New Harmony, Quail Creek State Park, Ivins,
Toquerville, Leeds, Pine Valley and Snow Canyon State Park.

This includes the following highways...
 Interstate 15 between mile markers 18 and 25.
 Utah Route 18 between mile markers 9 and 15.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3717 11335 3719 11367 3752 11360 3750 11326
TIME...MOT...LOC 2131Z 183DEG 7KT 3739 11345 

HAIL...1.00IN
WIND...60MPH
 
$$

ND

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 6:14 PM MDTAreal Flood AdvisorySLCWashington61 min
Jul 24, 3:23 AM MDTFlash Flood WatchSLCBeaver, Garfield, Iron, Kane, Piute, Washington and 1 more42 hr
Jul 24, 12:56 PM MDTFlash Flood Warning Considerable damage threatSLCKane3 hr
Jul 24, 12:58 PM MDTSpecial Weather StatementSLCKane32 min
Jul 24, 1:34 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane4 hr
Jul 24, 2:13 PM MDTFlash Flood Warning Considerable damage threatSLCWashington3 hr
Jul 24, 2:24 PM MDTSevere Thunderstorm WarningSLCWashington21 min
Jul 24, 3:40 PM MDTSevere Thunderstorm WarningSLCIron, Washington35 min
Jul 24, 4:04 PM MDTSevere Thunderstorm WarningSLCWashington26 min
Jul 24, 4:07 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Jul 24, 4:12 PM MDTFlash Flood Warning Considerable damage threatSLCIron, Washington3 hr
Jul 24, 4:30 PM MDTSevere Thunderstorm WarningSLCWashington30 min
Jul 24, 5:24 PM MDTFlash Flood Warning Considerable damage threatSLCWashington3 hr

Nearby

Severe Thunderstorm Warnings in Utah, 2021Every severe thunderstorm warning in 2021

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.