Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 27, NWS Salt Lake City, UT

July 22, 20214 counties in Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 22, 2021, 7:21 PM MDT for 4 counties in Utah. It was in force for 24 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, 7:21 PM MDT (01:21 UTC)
Expired
Jul 22, 2021, 7:45 PM MDT
In force
24 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Davis County, UT, Morgan County, UT, Salt Lake County, UT, Summit County, UT

The radar

The Salt Lake City radar (KMTX), 72 km from the middle of the area, began a volume at 01:19 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

Salt Lake City I, UT (KSLC), launched 00:00Z, 1.4 hours before the alert went out and 4 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, Salt Lake City I, UT at 00:00Z on 2021-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 775 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, Salt Lake City I, UT at 00:00Z on 2021-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 square meters per square second.193958Sfc1 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
775 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
2884 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

738 
WUUS55 KSLC 230121
SVRSLC
UTC011-029-035-043-230145-
/O.NEW.KSLC.SV.W.0027.210723T0121Z-210723T0145Z/

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

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northeastern Salt Lake County in northern Utah...
  Southeastern Davis County in northern Utah...
  South central Morgan County in northern Utah...
  Western Summit County in northern Utah...

* Until 745 PM MDT

* At 720 PM MDT, a severe thunderstorm was located near Salt Lake
  City, moving northeast at 15 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...
  Salt Lake City, Bountiful, North Salt Lake, Woods Cross, Summit
  Park, Emigration Canyon, Salt Lake City International Airport,
  University Of Utah and Sugarhouse.

This includes the following highways...
 Interstate 15 between mile markers 306 and 316.
 Interstate 80 in Utah between mile markers 114 and 119, and between
mile markers 131 and 138.

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 4074 11202 4088 11199 4087 11161 4072 11164
TIME...MOT...LOC 0120Z 227DEG 11KT 4076 11192 

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

ND
2 follow-up statements
772 
WWUS55 KSLC 230131
SVSSLC

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

UTC011-029-035-043-230145-
/O.CON.KSLC.SV.W.0027.000000T0000Z-210723T0145Z/
Salt Lake UT-Davis UT-Morgan UT-Summit UT-
731 PM MDT Thu Jul 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM MDT
FOR NORTHEASTERN SALT LAKE...SOUTHEASTERN DAVIS...SOUTH CENTRAL
MORGAN AND WESTERN SUMMIT COUNTIES...

At 731 PM MDT, a severe thunderstorm was located over Salt Lake City,
moving northeast at 15 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...
Salt Lake City, Bountiful, North Salt Lake, Woods Cross, Summit Park,
Emigration Canyon, Salt Lake City International Airport, University
Of Utah and Sugarhouse.

This includes the following highways...
 Interstate 15 between mile markers 306 and 316.
 Interstate 80 in Utah between mile markers 117 and 119, and between
mile markers 131 and 138.

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 4074 11196 4088 11193 4087 11161 4072 11164
TIME...MOT...LOC 0131Z 227DEG 11KT 4078 11189 

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

ND
493 
WWUS55 KSLC 230143
SVSSLC

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

UTC011-029-035-043-230153-
/O.EXP.KSLC.SV.W.0027.000000T0000Z-210723T0145Z/
Salt Lake UT-Davis UT-Morgan UT-Summit UT-
743 PM MDT Thu Jul 22 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN SALT LAKE...
SOUTHEASTERN DAVIS...SOUTH CENTRAL MORGAN AND WESTERN SUMMIT COUNTIES
WILL EXPIRE AT 745 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 gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 4074 11196 4088 11193 4087 11161 4072 11164
TIME...MOT...LOC 0143Z 227DEG 11KT 4080 11186 

$$

ND

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 6:01 PM MDTSpecial Weather StatementSLCTooele44 min
Jul 22, 6:47 PM MDTSpecial Weather StatementSLCUtah43 min
Jul 22, 6:53 PM MDTAreal Flood AdvisorySLCSalt Lake112 min
Jul 22, 7:03 PM MDTSpecial Weather StatementSLCDavis42 min
Jul 22, 7:07 PM MDTSevere Thunderstorm WarningSLCSalt Lake, Utah23 min
Jul 22, 7:23 PM MDTFlash Flood Warning Considerable damage threatSLCUtah82 min
Jul 22, 7:30 PM MDTSpecial Weather StatementSLCSalt Lake30 min
Jul 22, 7:37 PM MDTAreal Flood AdvisorySLCUtah105 min
Jul 22, 7:44 PM MDTSpecial Weather StatementSLCSalt Lake46 min
Jul 22, 7:52 PM MDTAreal Flood AdvisorySLCSalt Lake86 min
Jul 22, 8:01 PM MDTSpecial Weather StatementSLCMorgan29 min
Jul 22, 8:11 PM MDTSpecial Weather StatementSLCDavis49 min
Jul 22, 8:29 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake, Tooele31 min
Jul 22, 8:56 PM MDTSpecial Weather StatementSLCMorgan, Salt Lake, Weber49 min
Jul 23, 3:20 AM MDTFlash Flood WatchSLCBeaver, Garfield, Iron, Kane, Piute, Washington and 1 more21 hr
Jul 23, 2:34 PM MDTFlash Flood Warning Considerable damage threatSLCKane3 hr
Jul 23, 3:14 PM MDTSpecial Weather StatementSLCIron46 min
Jul 23, 3:27 PM MDTSpecial Weather StatementSLCBox Elder33 min
Jul 23, 4:04 PM MDTSpecial Weather StatementSLCCache26 min
Jul 23, 4:35 PM MDTSpecial Weather StatementSLCCache25 min
Jul 23, 5:03 PM MDTSpecial Weather StatementSLCCache27 min

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.