Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 25, NWS Salt Lake City, UT

July 22, 2021Iron County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 22, 2021, 4:28 PM MDT for Iron County, Utah. It was in force for 32 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 22, 2021, 4:28 PM MDT (22:28 UTC)
Expired
Jul 22, 2021, 5:00 PM MDT
In force
32 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Iron County, UT

The radar

The Cedar City radar (KICX), 60 km from the middle of the area, began a volume at 22:31 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, 10.5 hours before the alert went out and 238 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 2021-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 112 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 2021-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
112 J/kg
Mixed-layer CIN
-243 J/kg
Mixed-layer LCL
2637 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
-4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

581 
WUUS55 KSLC 222228
SVRSLC
UTC021-222300-
/O.NEW.KSLC.SV.W.0025.210722T2228Z-210722T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
428 PM MDT Thu Jul 22 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Western Iron County in southern Utah...

* Until 500 PM MDT

* At 426 PM MDT, a severe thunderstorm was located 26 miles west of
  Enoch, or 27 miles northwest of Cedar City, moving northeast at 20
  mph.

  HAZARD...Quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Damage to vehicles is expected. 

* Locations impacted include...
  Newcastle.

This includes the following highways...
 Utah Route 18 between mile markers 50 and 51.
 Utah Route 56 between mile markers 22 and 36.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

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

&&

LAT...LON 3762 11353 3772 11373 3805 11355 3786 11320
TIME...MOT...LOC 2226Z 211DEG 16KT 3787 11350 

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

ND
2 follow-up statements
586 
WWUS55 KSLC 222245
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
445 PM MDT Thu Jul 22 2021

UTC021-222300-
/O.CON.KSLC.SV.W.0025.000000T0000Z-210722T2300Z/
Iron UT-
445 PM MDT Thu Jul 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM MDT
FOR WESTERN IRON COUNTY...

At 444 PM MDT, a severe thunderstorm was located 25 miles northwest
of Enoch, or 27 miles northwest of Cedar City.

HAZARD...Quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Damage to vehicles is expected. 

Locations impacted include...
Newcastle.

This includes the following highways...
 Utah Route 18 between mile markers 50 and 51.
 Utah Route 56 between mile markers 22 and 36.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 3762 11353 3772 11373 3805 11355 3786 11320
TIME...MOT...LOC 2244Z 211DEG 16KT 3794 11345 

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

ND
560 
WWUS55 KSLC 222256
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
456 PM MDT Thu Jul 22 2021

UTC021-222305-
/O.EXP.KSLC.SV.W.0025.000000T0000Z-210722T2300Z/
Iron UT-
456 PM MDT Thu Jul 22 2021

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN IRON COUNTY WILL
EXPIRE AT 500 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However small hail
is still possible with this thunderstorm.

LAT...LON 3762 11353 3772 11373 3805 11355 3786 11320
TIME...MOT...LOC 2255Z 211DEG 16KT 3797 11343 

$$

ND

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 8:41 PM MDTFlash Flood Warning Considerable damage threatSLCKane6 hr
Jul 22, 2:43 AM MDTFlash Flood WatchSLCEmery, Garfield, Kane, Sevier, Washington, Wayne20 hr
Jul 22, 11:16 AM MDTSpecial Weather StatementSLCPiute29 min
Jul 22, 11:41 AM MDTSpecial Weather StatementSLC49 min
Jul 22, 11:54 AM MDTFlood WatchSLCBeaver, Garfield, Iron, Kane, Piute, Washington and 1 more11 hr
Jul 22, 1:02 PM MDTSpecial Weather StatementSLCIron43 min
Jul 22, 1:13 PM MDTSpecial Weather StatementSLCGarfield32 min
Jul 22, 1:18 PM MDTAreal Flood AdvisorySLCIron117 min
Jul 22, 1:20 PM MDTSevere Thunderstorm WarningSLCGarfield25 min
Jul 22, 1:45 PM MDTSpecial Weather StatementSLCKane45 min
Jul 22, 2:00 PM MDTSpecial Weather StatementSLCBeaver30 min
Jul 22, 2:13 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane3 hr
Jul 22, 2:13 PM MDTSevere Thunderstorm WarningSLCBeaver32 min
Jul 22, 2:34 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Jul 22, 2:42 PM MDTAreal Flood AdvisorySLCBeaver2 hr
Jul 22, 2:58 PM MDTSevere Thunderstorm WarningSLCWashington32 min
Jul 22, 3:08 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne3 hr
Jul 22, 3:14 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane5 hr
Jul 22, 3:14 PM MDTSpecial Weather StatementSLCWashington46 min
Jul 22, 3:30 PM MDTSevere Thunderstorm WarningSLCGarfield
Jul 22, 3:46 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane7 hr
Jul 22, 4:02 PM MDTSevere Thunderstorm WarningSLCIron28 min
Jul 22, 4:15 PM MDTSpecial Weather StatementSLCBox Elder30 min
Jul 22, 4:48 PM MDTSpecial Weather StatementSLCWashington27 min
Jul 22, 5:51 PM MDTSpecial Weather StatementSLC39 min
Jul 22, 5:58 PM MDTFlash Flood Warning Considerable damage threatSLCUtah3 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.