Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 29, NWS Salt Lake City, UT

July 24, 2021Washington County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 24, 2021, 2:24 PM MDT for Washington County, Utah. It was in force for 21 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 24, 2021, 2:24 PM MDT (20:24 UTC)
Expired
Jul 24, 2021, 2:45 PM MDT
In force
21 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Washington County, UT

The radar

The Cedar City radar (KICX), 65 km from the middle of the area, began a volume at 20:26 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.

What was reported inside it

TimeReportWhereRemark
Jul 24, 2:24 PM MDTTSTM WND DMGHildale, UTHILDALE DISPATCH REPORTED 10 POWERPOLES DOWN THROUGHOUT THE CITY ALONG WITH MULTIPLE DOWNED TREES. TIME ESTIMATED BY RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 8.4 hours before the alert went out and 230 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.

200 
WUUS55 KSLC 242024
SVRSLC
UTC053-242045-
/O.NEW.KSLC.SV.W.0029.210724T2024Z-210724T2045Z/

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

The National Weather Service in Salt Lake City has issued a

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

* Until 245 PM MDT

* At 222 PM MDT, a severe thunderstorm was located over Colorado
  City, moving southwest at 15 mph.

  HAZARD...Quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Damage to vehicles is expected. 

* Locations impacted include...
  Hildale.

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 3701 11321 3711 11306 3700 11289
TIME...MOT...LOC 2022Z 037DEG 12KT 3700 11304 

HAIL...1.00IN
WIND...<50MPH
 
$$

ND
2 follow-up statements
143 
WWUS55 KSLC 242035
SVSSLC

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

UTC053-242045-
/O.CON.KSLC.SV.W.0029.000000T0000Z-210724T2045Z/
Washington UT-
235 PM MDT Sat Jul 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM MDT
FOR SOUTHEASTERN WASHINGTON COUNTY...

At 234 PM MDT, a severe thunderstorm was located near Colorado City,
moving southwest at 15 mph.

HAZARD...Quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Damage to vehicles is expected. 

Locations impacted include...
Hildale.

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 3701 11314 3708 11305 3700 11289
TIME...MOT...LOC 2034Z 037DEG 12KT 3697 11307 

HAIL...1.00IN
WIND...<50MPH
 
$$

ND
722 
WWUS55 KSLC 242042
SVSSLC

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

UTC053-242051-
/O.EXP.KSLC.SV.W.0029.000000T0000Z-210724T2045Z/
Washington UT-
242 PM MDT Sat Jul 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN WASHINGTON COUNTY
WILL EXPIRE AT 245 PM MDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.

LAT...LON 3701 11314 3708 11305 3700 11289
TIME...MOT...LOC 2041Z 037DEG 12KT 3696 11308 

$$

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, 3:16 PM MDTSevere Thunderstorm WarningSLCWashington29 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.