Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 75, NWS Salt Lake City, UT

August 17, 2021Davis County, Salt Lake County, Tooele County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 17, 2021, 5:00 PM MDT for Davis County, Salt Lake County, Tooele County, Utah. It was in force for 30 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 17, 2021, 5:00 PM MDT (23:00 UTC)
Expired
Aug 17, 2021, 5:30 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

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

The radar

The Salt Lake City radar (KMTX), 42 km from the middle of the area, began a volume at 23:02 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.

What was reported inside it

TimeReportWhereRemark
Aug 17, 5:19 PM MDTTSTM WND GST 65Ne Lake Pt, UTTHUNDERSTORM WIND GUST MEASURED AT THE MARINA STATION.
Aug 17, 5:19 PM MDTTSTM WND GST 65Ne Lake Pt, UTTHUNDERSTORM WIND GUST MEASURED AT THE MARINA STATION.
Aug 17, 5:23 PM MDTTSTM WND GST 684 Nw Magna, UTTHUNDERSTORM WIND GUST OF 68 MPH MEASURED AT THE CENTER TAILINGS STATION.
Aug 17, 5:23 PM MDTTSTM WND GST 684 Nw Magna, UTTHUNDERSTORM WIND GUST OF 68 MPH MEASURED AT THE CENTER TAILINGS STATION.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 12:00Z, 11.0 hours before the alert went out and 29 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 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3488 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

299 
WUUS55 KSLC 172300
SVRSLC
UTC011-035-045-172330-
/O.NEW.KSLC.SV.W.0075.210817T2300Z-210817T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
500 PM MDT Tue Aug 17 2021

The National Weather Service in Salt Lake City has issued a

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

* Until 530 PM MDT

* At 459 PM MDT, a severe thunderstorm was located over Stansbury
  Park, or 7 miles north of Tooele, moving northeast at 40 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, West Valley City, Layton, Bountiful, Farmington,
  Grantsville, Hill Air Force Base, Clearfield, Kaysville, Syracuse,
  Clinton, North Salt Lake, Centerville, Woods Cross, Stansbury Park,
  South Weber, West Bountiful, Uintah, Salt Lake City International
  Airport and Magna.

This includes the following highways...
 Interstate 15 between mile markers 307 and 337.
 Interstate 84 between mile markers 86 and 87.
 Interstate 80 in Utah between mile markers 83 and 119.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

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 4113 11186 4076 11185 4057 11239 4073 11256
      4107 11250 4115 11219 4115 11199
TIME...MOT...LOC 2259Z 225DEG 33KT 4064 11230 

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

$$

MPS
1 follow-up statement
102 
WWUS55 KSLC 172319
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
519 PM MDT Tue Aug 17 2021

UTC011-035-045-172330-
/O.CON.KSLC.SV.W.0075.000000T0000Z-210817T2330Z/
Salt Lake UT-Davis UT-Tooele UT-
519 PM MDT Tue Aug 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM MDT
FOR NORTHWESTERN SALT LAKE...DAVIS AND NORTHEASTERN TOOELE
COUNTIES...

At 517 PM MDT, a severe thunderstorm was located near Stansbury Park,
or 10 miles west of West Valley City, moving northeast at 30 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. At 505 PM a 65 mph wind gust was reported 
         at the Great Salt Lake Marina.  

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Salt Lake City, West Valley City, Layton, Bountiful, Farmington,
Grantsville, Hill Air Force Base, Clearfield, Kaysville, Syracuse,
Clinton, North Salt Lake, Centerville, Woods Cross, Stansbury Park,
South Weber, West Bountiful, Uintah, Salt Lake City International
Airport and Magna.

This includes the following highways...
 Interstate 15 between mile markers 307 and 337.
 Interstate 84 between mile markers 86 and 87.
 Interstate 80 in Utah between mile markers 83 and 119.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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 4113 11186 4076 11185 4057 11239 4073 11256
      4107 11250 4115 11219 4115 11199
TIME...MOT...LOC 2317Z 227DEG 28KT 4068 11220 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...70 MPH

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 1:31 PM MDTSpecial Weather StatementSLCKane44 min
Aug 17, 1:50 PM MDTSevere Thunderstorm WarningSLCGarfield, Kane20 min
Aug 17, 2:23 PM MDTSevere Thunderstorm WarningSLCBeaver, Garfield, Piute52 min
Aug 17, 2:50 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield3 hr
Aug 17, 3:14 PM MDTSpecial Weather StatementSLCJuab31 min
Aug 17, 3:20 PM MDTSpecial Weather StatementSLCTooele25 min
Aug 17, 3:29 PM MDTSevere Thunderstorm WarningSLCSevier46 min
Aug 17, 3:51 PM MDTSevere Thunderstorm WarningSLCTooele24 min
Aug 17, 4:12 PM MDTSevere Thunderstorm Warning Considerable damage threatSLCTooele48 min
Aug 17, 4:18 PM MDTFlash Flood Warning Considerable damage threatSLCEmery, Wayne3 hr
Aug 17, 4:29 PM MDTSevere Thunderstorm WarningSLCTooele46 min
Aug 17, 4:39 PM MDTSevere Thunderstorm Warning Considerable damage threatSLCMillard66 min
Aug 17, 4:53 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield3 hr
Aug 17, 4:56 PM MDTSevere Thunderstorm WarningSLCGarfield24 min
Aug 17, 5:10 PM MDTFlash Flood Warning Considerable damage threatSLCKane4 hr
Aug 17, 5:12 PM MDTSevere Thunderstorm WarningSLCTooele63 min
Aug 17, 5:30 PM MDTSevere Thunderstorm Warning Considerable damage threatSLCDavis, Salt Lake45 min
Aug 17, 5:37 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield, Kane6 hr
Aug 17, 5:40 PM MDTSevere Thunderstorm WarningSLCMillard50 min
Aug 17, 5:48 PM MDTSpecial Weather StatementSLCSanpete27 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.