Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 53, NWS Salt Lake City, UT

July 31, 2021Iron County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 31, 2021, 4:00 PM MDT for Iron County, Utah. It was in force for 30 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 31, 2021, 4:00 PM MDT (22:00 UTC)
Expired
Jul 31, 2021, 4:30 PM MDT
In force
30 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Iron County, UT

The radar

The Cedar City radar (KICX), 47 km from the middle of the area, began a volume at 21:59 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, 10.0 hours before the alert went out and 252 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 2021-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 134 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 2021-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
134 J/kg
Mixed-layer CIN
-129 J/kg
Mixed-layer LCL
2161 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

535 
WUUS55 KSLC 312200
SVRSLC
UTC021-312230-
/O.NEW.KSLC.SV.W.0053.210731T2200Z-210731T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
400 PM MDT Sat Jul 31 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 430 PM MDT

* At 359 PM MDT, a severe thunderstorm was located 14 miles west of
  Enoch, or 15 miles northwest of Cedar City, moving northwest at 5
  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. 

* This severe thunderstorm will remain over mainly rural areas of
  central Iron County.

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 3780 11323 3770 11329 3776 11351 3794 11335
TIME...MOT...LOC 2159Z 126DEG 4KT 3778 11332 

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

ND
2 follow-up statements
932 
WWUS55 KSLC 312215
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
415 PM MDT Sat Jul 31 2021

UTC021-312230-
/O.CON.KSLC.SV.W.0053.000000T0000Z-210731T2230Z/
Iron UT-
415 PM MDT Sat Jul 31 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR CENTRAL IRON COUNTY...

At 415 PM MDT, a severe thunderstorm was located 16 miles west of
Enoch, or 16 miles northwest of Cedar City, 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. 

This severe thunderstorm will remain over mainly rural areas of
central Iron County.

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 3781 11327 3774 11334 3779 11347 3794 11335
TIME...MOT...LOC 2215Z 126DEG 4KT 3779 11334 

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

ND
402 
WWUS55 KSLC 312221
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
421 PM MDT Sat Jul 31 2021

UTC021-312231-
/O.EXP.KSLC.SV.W.0053.000000T0000Z-210731T2230Z/
Iron UT-
421 PM MDT Sat Jul 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL IRON COUNTY WILL
EXPIRE AT 430 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.

LAT...LON 3781 11327 3774 11334 3779 11347 3794 11335
TIME...MOT...LOC 2221Z 126DEG 4KT 3779 11334 

$$

ND

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 7:17 PM MDTSpecial Weather StatementSLCBeaver43 min
Jul 30, 7:31 PM MDTSpecial Weather StatementSLC44 min
Jul 31, 12:31 PM MDTSpecial Weather StatementSLCSummit44 min
Jul 31, 1:12 PM MDTSpecial Weather StatementSLCIron33 min
Jul 31, 1:23 PM MDTFlash Flood Warning Considerable damage threatSLCDuchesne, Wasatch3 hr
Jul 31, 1:30 PM MDTSevere Thunderstorm WarningSLCIron, Washington30 min
Jul 31, 1:39 PM MDTSpecial Weather StatementSLCMorgan36 min
Jul 31, 2:10 PM MDTSpecial Weather StatementSLCMorgan50 min
Jul 31, 2:38 PM MDTSpecial Weather StatementSLCMorgan37 min
Jul 31, 2:47 PM MDTSevere Thunderstorm WarningSLCMorgan, Rich, Summit28 min
Jul 31, 2:52 PM MDTSpecial Weather StatementSLCRich23 min
Jul 31, 3:00 PM MDTAreal Flood AdvisorySLCIron107 min
Jul 31, 3:10 PM MDTSpecial Weather StatementSLCMorgan20 min
Jul 31, 3:16 PM MDTSevere Thunderstorm WarningSLCBox Elder, Cache, Weber29 min
Jul 31, 3:35 PM MDTFlash Flood Warning Considerable damage threatSLCIron3 hr
Jul 31, 3:41 PM MDTSpecial Weather StatementSLCCache19 min
Jul 31, 4:06 PM MDTSpecial Weather StatementSLCBeaver24 min
Jul 31, 4:10 PM MDTFlash Flood Warning Considerable damage threatSLCUtah3 hr
Jul 31, 4:19 PM MDTFlash Flood Warning Considerable damage threatSLCDuchesne3 hr
Jul 31, 4:39 PM MDTSpecial Weather StatementSLCRich66 min
Jul 31, 5:01 PM MDTSpecial Weather StatementSLC29 min
Jul 31, 5:11 PM MDTFlash Flood Warning Considerable damage threatSLCWashington3 hr
Jul 31, 5:25 PM MDTSpecial Weather StatementSLCJuab35 min
Jul 31, 5:37 PM MDTSpecial Weather StatementSLCWashington38 min
Jul 31, 5:39 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington5 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.