Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 105, NWS Salt Lake City, UT

September 10, 2021Davis County, Salt Lake County, Tooele County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 10, 2021, 6:50 PM MDT for Davis County, Salt Lake County, Tooele County, Utah. It was in force for 25 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
Sep 10, 2021, 6:50 PM MDT (00:50 UTC)
Expired
Sep 10, 2021, 7:15 PM MDT
In force
25 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 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 00:51 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, 0.8 hours before the alert went out and 15 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 2021-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 430 joules per kilogram.LCLEL10008507005003002001001 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 2021-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 128 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
430 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
3241 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
128 m²/s²
0-3 km storm-relative helicity
161 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2

Open this sounding in Storm Lab

The text

As transmitted.

263 
WUUS55 KSLC 110050
SVRSLC
UTC011-035-045-110115-
/O.NEW.KSLC.SV.W.0105.210911T0050Z-210911T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
650 PM MDT Fri Sep 10 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northwestern Salt Lake County in northern Utah...
  Central Davis County in northern Utah...
  Northeastern Tooele County in northern Utah...

* Until 715 PM MDT

* At 649 PM MDT, a severe thunderstorm was located 7 miles northwest
  of Magna, or 11 miles northwest of West Valley City, moving
  northeast at 35 mph.

  HAZARD...60 mph wind gusts and penny size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Salt Lake City, Layton, Bountiful, Farmington, Clearfield,
  Kaysville, Syracuse, North Salt Lake, Centerville, Woods Cross,
  West Bountiful, Salt Lake City International Airport, Fruit Heights
  and Antelope Island State Park.

This includes the following highways...
 Interstate 15 between mile markers 312 and 333.
 Interstate 80 in Utah between mile markers 102 and 113.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4097 11178 4096 11182 4090 11177 4088 11177
      4070 11219 4080 11234 4111 11202
TIME...MOT...LOC 0049Z 229DEG 32KT 4079 11219 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Webber
2 follow-up statements
755 
WWUS55 KSLC 110105
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
705 PM MDT Fri Sep 10 2021

UTC011-035-045-110115-
/O.CON.KSLC.SV.W.0105.000000T0000Z-210911T0115Z/
Salt Lake UT-Davis UT-Tooele UT-
705 PM MDT Fri Sep 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM MDT
FOR NORTHWESTERN SALT LAKE...CENTRAL DAVIS AND NORTHEASTERN TOOELE
COUNTIES...

At 705 PM MDT, a severe thunderstorm was located 7 miles west of West
Bountiful, or 9 miles west of Bountiful, moving northeast at 35 mph.

HAZARD...60 mph wind gusts and penny size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Salt Lake City, Layton, Bountiful, Farmington, Clearfield, Kaysville,
Syracuse, North Salt Lake, Centerville, Woods Cross, West Bountiful,
Salt Lake City International Airport, Fruit Heights and Antelope
Island State Park.

This includes the following highways...
 Interstate 15 between mile markers 312 and 333.
 Interstate 80 in Utah between mile markers 102 and 113.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4097 11178 4096 11182 4090 11177 4088 11177
      4070 11219 4080 11234 4111 11202
TIME...MOT...LOC 0105Z 229DEG 32KT 4089 11204 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Webber
978 
WWUS55 KSLC 110113
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
713 PM MDT Fri Sep 10 2021

UTC011-035-045-110122-
/O.EXP.KSLC.SV.W.0105.000000T0000Z-210911T0115Z/
Salt Lake UT-Davis UT-Tooele UT-
713 PM MDT Fri Sep 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SALT LAKE...
CENTRAL DAVIS AND NORTHEASTERN TOOELE COUNTIES WILL EXPIRE AT 715 PM
MDT...
        
The storm which prompted the warning has moved out of the area. A 
new warning has been issued for the storm. 

LAT...LON 4097 11178 4096 11182 4090 11177 4088 11177
      4070 11219 4080 11234 4111 11202
TIME...MOT...LOC 0112Z 229DEG 32KT 4093 11198 

$$

Webber

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 10, 6:06 PM MDTSevere Thunderstorm WarningSLCBox Elder, Weber39 min
Sep 10, 6:20 PM MDTSevere Thunderstorm WarningSLCDavis, Morgan, Weber25 min
Sep 10, 6:42 PM MDTSpecial Weather StatementSLCMorgan, Weber33 min
Sep 10, 6:42 PM MDTSpecial Weather StatementSLCDavis33 min
Sep 10, 7:10 PM MDTSpecial Weather StatementSLCSalt Lake, Utah50 min
Sep 10, 7:10 PM MDTSevere Thunderstorm WarningSLCDavis, Morgan, Salt Lake, Weber35 min
Sep 10, 7:16 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake29 min
Sep 10, 7:24 PM MDTSpecial Weather StatementSLCRich51 min
Sep 10, 7:24 PM MDTSpecial Weather StatementSLCCache51 min
Sep 10, 7:38 PM MDTSpecial Weather StatementSLCCache, Morgan, Rich, Weber52 min
Sep 11, 12:50 PM MDTFlash Flood Warning Considerable damage threatSLCWayne3 hr
Sep 11, 12:54 PM MDTSpecial Weather StatementSLCCarbon51 min
Sep 11, 1:39 PM MDTSpecial Weather StatementSLCDuchesne51 min
Sep 11, 1:40 PM MDTFlash Flood Warning Considerable damage threatSLCCarbon3 hr
Sep 11, 3:17 PM MDTSpecial Weather StatementSLCDuchesne43 min
Sep 11, 4:25 PM MDTSpecial Weather StatementSLCMillard35 min
Sep 11, 5:10 PM MDTSpecial Weather StatementSLCJuab35 min
Sep 11, 5:19 PM MDTSpecial Weather StatementSLCMillard26 min
Sep 11, 5:44 PM MDTSpecial Weather StatementSLCMillard46 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.