Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 28, NWS Salt Lake City, UT

July 22, 2021Davis County, Salt Lake County, Tooele County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 22, 2021, 8:29 PM MDT for Davis County, Salt Lake County, Tooele County, Utah. It was in force for 31 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, 8:29 PM MDT (02:29 UTC)
Expired
Jul 22, 2021, 9:00 PM MDT
In force
31 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
0.75 in
Wind
70.0 mph

Counties Davis County, UT, Salt Lake County, UT, Tooele County, UT

The radar

The Salt Lake City radar (KMTX), 58 km from the middle of the area, began a volume at 02:33 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, 2.5 hours before the alert went out and 20 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.

579 
WUUS55 KSLC 230229
SVRSLC
UTC011-035-045-230300-
/O.NEW.KSLC.SV.W.0028.210723T0229Z-210723T0300Z/

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

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northwestern Salt Lake County in northern Utah...
  Southern Davis County in northern Utah...
  East central Tooele County in northern Utah...

* Until 900 PM MDT

* At 828 PM MDT, a severe thunderstorm was located near Salt Lake
  City International Airport, or 8 miles west of Bountiful, moving 
  east at 20 mph. 70 mph winds have been reported in this 
  thunderstorm.

  HAZARD...70 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings. 

* Locations impacted include...
  Salt Lake City, West Valley City, Layton, Bountiful, Farmington,
  Kaysville, North Salt Lake, Centerville, Woods Cross, West
  Bountiful, Salt Lake City International Airport, Magna, Great Salt
  Lake South of the Causeway, Lake Point and Antelope Island State
  Park.

This includes the following highways...
 Interstate 15 between mile markers 308 and 322, and between mile
markers 325 and 329.
 Interstate 80 in Utah between mile markers 97 and 119.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near the Great Salt Lake, get away from the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4063 11226 4088 11241 4106 11194 4080 11181
TIME...MOT...LOC 0228Z 251DEG 15KT 4085 11203 

HAIL...<.75IN
WIND...70MPH
 
$$

ND
2 follow-up statements
447 
WWUS55 KSLC 230244
SVSSLC

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

UTC011-035-045-230300-
/O.CON.KSLC.SV.W.0028.000000T0000Z-210723T0300Z/
Salt Lake UT-Davis UT-Tooele UT-
844 PM MDT Thu Jul 22 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM MDT
FOR NORTHWESTERN SALT LAKE...SOUTHERN DAVIS AND EAST CENTRAL TOOELE
COUNTIES...

At 843 PM MDT, a severe thunderstorm was located over Woods Cross, or
near Bountiful, moving east at 15 mph.

HAZARD...70 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings. 

Locations impacted include...
Salt Lake City, West Valley City, Layton, Bountiful, Farmington,
Kaysville, North Salt Lake, Centerville, Woods Cross, West Bountiful,
Salt Lake City International Airport, Magna, Great Salt Lake South of
the Causeway, Lake Point and Antelope Island State Park.

This includes the following highways...
 Interstate 15 between mile markers 308 and 322, and between mile
markers 325 and 329.
 Interstate 80 in Utah between mile markers 97 and 119.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near the Great Salt Lake, get away from the water and move 
indoors or inside a vehicle. remember, lightning can strike out to 
15 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now!  Do not be caught on the water in a thunderstorm.

&&

LAT...LON 4063 11226 4088 11241 4106 11194 4080 11181
TIME...MOT...LOC 0243Z 251DEG 15KT 4087 11195 

HAIL...<.75IN
WIND...70MPH
 
$$

ND
559 
WWUS55 KSLC 230256
SVSSLC

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

UTC011-035-045-230306-
/O.EXP.KSLC.SV.W.0028.000000T0000Z-210723T0300Z/
Salt Lake UT-Davis UT-Tooele UT-
856 PM MDT Thu Jul 22 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SALT LAKE...
SOUTHERN DAVIS AND EAST CENTRAL TOOELE COUNTIES WILL EXPIRE AT 900 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 are still possible with this thunderstorm.

LAT...LON 4063 11226 4088 11241 4106 11194 4080 11181
TIME...MOT...LOC 0256Z 251DEG 15KT 4089 11189 

$$

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, 7:21 PM MDTSevere Thunderstorm WarningSLCDavis, Morgan, Salt Lake, Summit24 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, 8:56 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.