Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 85, NWS Salt Lake City, UT

August 18, 2021Juab County, Tooele County, Utah County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 18, 2021, 1:24 PM MDT for Juab County, Tooele County, Utah County, Utah. It was in force for 81 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
Aug 18, 2021, 1:24 PM MDT (19:24 UTC)
Expired
Aug 18, 2021, 2:45 PM MDT
In force
81 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties Juab County, UT, Tooele County, UT, Utah County, UT

The radar

The Salt Lake City radar (KMTX), 162 km from the middle of the area, began a volume at 19:26 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 18, 12:14 PM MDTSevere Thunderstorm WatchSPC8 hr

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 7.4 hours before the alert went out and 96 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 12:00Z on 2021-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 12:00Z on 2021-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 square meters per square second.19395878Sfc1 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
7 J/kg
Mixed-layer CIN
-398 J/kg
Mixed-layer LCL
1192 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
17 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

071 
WUUS55 KSLC 181924
SVRSLC
UTC023-045-049-182045-
/O.NEW.KSLC.SV.W.0085.210818T1924Z-210818T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
124 PM MDT Wed Aug 18 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northeastern Juab County in central Utah...
  Utah County in northern Utah...
  Southeastern Tooele County in northern Utah...

* Until 245 PM MDT

* At 124 PM MDT, severe thunderstorms were located along a line
  extending from 11 miles east of Vernon to 10 miles west of Nephi,
  moving northeast at 35 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...
  Provo, Payson, Nephi, Orem, Lehi, Spanish Fork, Pleasant Grove,
  Springville, American Fork, Eagle Mountain, Lindon, Alpine,
  Santaquin, Mapleton, Salem, Elk Ridge, Woodland Hills, Rocky Ridge,
  Vineyard and Brigham Young University.

This includes the following highways...
 Interstate 15 between mile markers 217 and 283.
 US Route 6 between mile markers 118 and 195.
 US Route 89 between mile markers 297 and 312.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3984 11125 3981 11137 3981 11164 3978 11162
      3978 11158 3974 11159 3972 11171 3964 11178
      3956 11222 4013 11241 4054 11166 4046 11161
      4044 11162
TIME...MOT...LOC 1924Z 234DEG 32KT 4006 11224 3968 11202 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church
4 follow-up statements
340 
WWUS55 KSLC 181946
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
146 PM MDT Wed Aug 18 2021

UTC045-181955-
/O.CAN.KSLC.SV.W.0085.000000T0000Z-210818T2045Z/
Tooele UT-
146 PM MDT Wed Aug 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN TOOELE COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A severe thunderstorm watch remains in effect until 800 PM MDT for
central and northern Utah.

LAT...LON 3981 11137 3981 11164 3978 11162 3978 11158
      3974 11159 3961 11214 4002 11217 4021 11215
      4025 11218 4054 11166 4046 11161 4044 11162
      3984 11125
TIME...MOT...LOC 1945Z 234DEG 32KT 4016 11206 3978 11184 

$$

UTC023-049-182045-
/O.CON.KSLC.SV.W.0085.000000T0000Z-210818T2045Z/
Juab UT-Utah UT-
146 PM MDT Wed Aug 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM MDT
FOR NORTHEASTERN JUAB AND UTAH COUNTIES...

At 145 PM MDT, severe thunderstorms were located along a line
extending from 10 miles south of Eagle Mountain to near Nephi, moving
northeast at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Provo, Payson, Nephi, Orem, Lehi, Spanish Fork, Pleasant Grove,
Springville, American Fork, Eagle Mountain, Lindon, Alpine,
Santaquin, Mapleton, Salem, Elk Ridge, Woodland Hills, Rocky Ridge,
Vineyard and Brigham Young University.

This includes the following highways...
 Interstate 15 between mile markers 223 and 282.
 US Route 6 between mile markers 127 and 195.
 US Route 89 between mile markers 297 and 312.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3981 11137 3981 11164 3978 11162 3978 11158
      3974 11159 3961 11214 4002 11217 4021 11215
      4025 11218 4054 11166 4046 11161 4044 11162
      3984 11125
TIME...MOT...LOC 1945Z 234DEG 32KT 4016 11206 3978 11184 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church
612 
WWUS55 KSLC 182005
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
205 PM MDT Wed Aug 18 2021

UTC023-049-182045-
/O.CON.KSLC.SV.W.0085.000000T0000Z-210818T2045Z/
Juab UT-Utah UT-
205 PM MDT Wed Aug 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM MDT
FOR EAST CENTRAL JUAB AND CENTRAL UTAH COUNTIES...

At 205 PM MDT, severe thunderstorms were located along a line
extending from 6 miles northwest of Utah Lake to 9 miles southeast of
Rocky Ridge, moving east at 35 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...
Provo, Payson, Nephi, Orem, Lehi, Spanish Fork, Pleasant Grove,
Springville, American Fork, Eagle Mountain, Lindon, Alpine,
Santaquin, Mapleton, Salem, Elk Ridge, Woodland Hills, Rocky Ridge,
Vineyard and Brigham Young University.

This includes the following highways...
 Interstate 15 between mile markers 224 and 283.
 US Route 6 between mile markers 150 and 195.
 US Route 89 between mile markers 297 and 312.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3962 11211 4001 11193 4037 11197 4054 11166
      4046 11161 4044 11162 3986 11126 3981 11143
      3981 11164 3978 11162 3978 11158 3974 11159
TIME...MOT...LOC 2005Z 270DEG 32KT 4024 11188 3986 11166 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church
874 
WWUS55 KSLC 182030
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
230 PM MDT Wed Aug 18 2021

UTC023-049-182045-
/O.CON.KSLC.SV.W.0085.000000T0000Z-210818T2045Z/
Juab UT-Utah UT-
230 PM MDT Wed Aug 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM MDT
FOR EAST CENTRAL JUAB AND SOUTHWESTERN UTAH COUNTIES...

At 229 PM MDT, severe thunderstorms were located along a line
extending from near Lindon to 10 miles east of Woodland Hills, moving
northeast at 35 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Provo, Payson, Nephi, Spanish Fork, Springville, Santaquin, Mapleton,
Salem, Elk Ridge, Woodland Hills, Rocky Ridge, Benjamin, Palmyra,
Lake Shore, Spring Lake, West Mountain, Elberta, Utah Lake, Mona and
Genola.

This includes the following highways...
 Interstate 15 between mile markers 224 and 263.
 US Route 6 between mile markers 150 and 195.
 US Route 89 between mile markers 297 and 312.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3962 11211 4001 11193 4030 11153 3986 11126
      3981 11143 3981 11164 3978 11162 3978 11158
      3974 11159
TIME...MOT...LOC 2029Z 234DEG 32KT 4036 11167 3998 11145 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church
441 
WWUS55 KSLC 182038
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
238 PM MDT Wed Aug 18 2021

UTC023-049-182047-
/O.EXP.KSLC.SV.W.0085.000000T0000Z-210818T2045Z/
Juab UT-Utah UT-
238 PM MDT Wed Aug 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL JUAB AND
SOUTHWESTERN UTAH COUNTIES WILL EXPIRE AT 245 PM MDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with these thunderstorms.

A severe thunderstorm watch remains in effect until 800 PM MDT for
central and northern Utah.

LAT...LON 3962 11211 4001 11193 4030 11153 3986 11126
      3981 11143 3981 11164 3978 11162 3978 11158
      3974 11159
TIME...MOT...LOC 2037Z 234DEG 32KT 4039 11162 4001 11140 

$$

Church

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 6:05 PM MDTFlash Flood Warning Considerable damage threatSLCMillard3 hr
Aug 17, 6:10 PM MDTSevere Thunderstorm WarningSLCJuab35 min
Aug 17, 6:31 PM MDTSevere Thunderstorm WarningSLCMillard59 min
Aug 17, 6:39 PM MDTSpecial Weather StatementSLCUtah36 min
Aug 17, 6:49 PM MDTSevere Thunderstorm WarningSLCUtah, Wasatch26 min
Aug 17, 6:57 PM MDTFlash Flood Warning Considerable damage threatSLCKane, San Juan5 hr
Aug 17, 7:14 PM MDTSevere Thunderstorm WarningSLCSummit, Wasatch31 min
Aug 17, 8:52 PM MDTSpecial Weather StatementSLCSalt Lake38 min
Aug 17, 9:30 PM MDTSpecial Weather StatementSLCTooele30 min
Aug 17, 9:55 PM MDTSpecial Weather StatementSLCKane35 min
Aug 17, 9:58 PM MDTSpecial Weather StatementSLCJuab32 min
Aug 17, 10:00 PM MDTSpecial Weather StatementSLCJuab30 min
Aug 17, 10:17 PM MDTSpecial Weather StatementSLCSalt Lake28 min
Aug 18, 12:23 AM MDTSpecial Weather StatementSLC52 min
Aug 18, 12:31 AM MDTSpecial Weather StatementSLCMillard44 min
Aug 18, 12:45 AM MDTSpecial Weather StatementSLCJuab45 min
Aug 18, 1:42 AM MDTSpecial Weather StatementSLCJuab48 min
Aug 18, 4:38 AM MDTFlash Flood Warning Considerable damage threatSLCIron5 hr
Aug 18, 4:41 AM MDTFlash Flood Warning Considerable damage threatSLCIron3 hr
Aug 18, 6:02 AM MDTFlash Flood Warning Considerable damage threatSLCIron, Washington4 hr
Aug 18, 7:30 AM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington90 min
Aug 18, 7:55 AM MDTAreal Flood WarningSLCGarfield, Iron, Kane, Washington6 hr
Aug 18, 8:58 AM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington92 min
Aug 18, 11:05 AM MDTSevere Thunderstorm WarningSLCTooele40 min
Aug 18, 11:45 AM MDTSpecial Weather StatementSLCSalt Lake45 min
Aug 18, 12:11 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Wayne6 hr
Aug 18, 12:17 PM MDTAreal Flood AdvisorySLCDavis, Salt Lake, Tooele2 hr
Aug 18, 12:29 PM MDTSpecial Weather StatementSLC31 min
Aug 18, 12:34 PM MDTSevere Thunderstorm WarningSLCJuab, Tooele56 min
Aug 18, 12:47 PM MDTSpecial Weather StatementSLCPiute28 min
Aug 18, 1:05 PM MDTFlash Flood Warning Considerable damage threatSLCWayne3 hr
Aug 18, 1:12 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield2 hr
Aug 18, 1:14 PM MDTSpecial Weather StatementSLCBeaver31 min
Aug 18, 1:24 PM MDTAreal Flood WarningSLCJuab, Salt Lake, Tooele, Utah3 hr
Aug 18, 1:39 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Aug 18, 1:57 PM MDTAreal Flood AdvisorySLCSalt Lake, Utah2 hr
Aug 18, 2:27 PM MDTFlash Flood Warning Considerable damage threatSLCUtah3 hr
Aug 18, 2:37 PM MDTFlash Flood Warning Considerable damage threatSLCUtah113 min
Aug 18, 2:51 PM MDTSpecial Weather StatementSLCSummit24 min
Aug 18, 2:56 PM MDTSpecial Weather StatementSLCGarfield49 min
Aug 18, 3:14 PM MDTSpecial Weather StatementSLCKane46 min
Aug 18, 3:18 PM MDTSpecial Weather StatementSLCWasatch27 min
Aug 18, 3:25 PM MDTFlash Flood Warning Considerable damage threatSLCUtah3 hr
Aug 18, 3:41 PM MDTSpecial Weather StatementSLCSanpete49 min
Aug 18, 3:46 PM MDTFlash Flood Warning Considerable damage threatSLCEmery, Wayne3 hr
Aug 18, 4:16 PM MDTSpecial Weather StatementSLCKane44 min
Aug 18, 4:22 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield3 hr
Aug 18, 5:41 PM MDTSpecial Weather StatementSLC49 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.