Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 31, NWS Salt Lake City, UT

July 24, 2021Iron County, Washington County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 24, 2021, 3:40 PM MDT for Iron County, Washington 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 outline as issued.

The facts

Issued
Jul 24, 2021, 3:40 PM MDT (21:40 UTC)
Expired
Jul 24, 2021, 4:15 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 Iron County, UT, Washington County, UT

The radar

The Cedar City radar (KICX), 60 km from the middle of the area, began a volume at 21:44 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, 9.7 hours before the alert went out and 215 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.

548 
WUUS55 KSLC 242140
SVRSLC
UTC021-053-242215-
/O.NEW.KSLC.SV.W.0031.210724T2140Z-210724T2215Z/

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

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  North central Washington County in southwestern Utah...
  South central Iron County in southern Utah...

* Until 415 PM MDT

* At 339 PM MDT, a severe thunderstorm was located 10 miles northeast
  of Dameron Valley, or 31 miles east of Beaver Dam, moving northwest
  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...
  Pine Valley, Pinto and Veyo. 

This includes Utah Route 18 between mile markers 23 and 32.
 
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 3736 11335 3726 11354 3743 11375 3758 11347
TIME...MOT...LOC 2139Z 146DEG 8KT 3737 11350 

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

ND
2 follow-up statements
860 
WWUS55 KSLC 242159
SVSSLC

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

UTC021-242208-
/O.CAN.KSLC.SV.W.0031.000000T0000Z-210724T2215Z/
Iron UT-
359 PM MDT Sat Jul 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL IRON COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, this warning has been cancelled.

LAT...LON 3734 11340 3726 11354 3743 11375 3753 11357
TIME...MOT...LOC 2158Z 146DEG 8KT 3741 11353 

$$

UTC053-242215-
/O.CON.KSLC.SV.W.0031.000000T0000Z-210724T2215Z/
Washington UT-
359 PM MDT Sat Jul 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 415 PM MDT
FOR CENTRAL WASHINGTON COUNTY...

At 358 PM MDT, a severe thunderstorm was located 10 miles northeast
of Dameron Valley, or 29 miles east of Beaver Dam, moving northwest
at 10 mph.

HAZARD...70 mph wind gusts and ping pong ball size hail. 

SOURCE...Radar indicated. 

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings. 

Locations impacted include...
Pine Valley and Veyo. 

This includes Utah Route 18 between mile markers 23 and 32.
 
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 3734 11340 3726 11354 3743 11375 3753 11357
TIME...MOT...LOC 2158Z 146DEG 8KT 3741 11353 

HAIL...1.50IN
WIND...70MPH
 
$$

ND
290 
WWUS55 KSLC 242212
SVSSLC

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

UTC053-242222-
/O.EXP.KSLC.SV.W.0031.000000T0000Z-210724T2215Z/
Washington UT-
412 PM MDT Sat Jul 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL WASHINGTON COUNTY WILL
EXPIRE AT 415 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

LAT...LON 3734 11340 3726 11354 3743 11375 3753 11357
TIME...MOT...LOC 2212Z 146DEG 8KT 3743 11355 

$$

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, 3:16 PM MDTSevere Thunderstorm WarningSLCWashington29 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.