Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 74, NWS Salt Lake City, UT

August 17, 2021Garfield County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 17, 2021, 4:56 PM MDT for Garfield County, 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: Aug 17, 2021, 4:56 PM MDT (22:56 UTC)
Expired: Aug 17, 2021, 5:20 PM MDT
In force: 24 min
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

County Garfield County, UT

The radar

The Cedar City radar (KICX), 146 km from the middle of the area, began a volume at 22:59 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.9 hours before the alert went out and 279 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 984 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 829 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 154 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.8

Open this sounding in Storm Lab

The text

As transmitted.

916 
WUUS55 KSLC 172256
SVRSLC
UTC017-172345-
/O.NEW.KSLC.SV.W.0074.210817T2256Z-210817T2345Z/

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

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  South central Garfield County in southern Utah...

* Until 545 PM MDT

* At 455 PM MDT, a severe thunderstorm was located 16 miles southeast
  of Boulder, or 18 miles east of Escalante, moving northeast at 15
  mph.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees. 

* This severe thunderstorm will remain over mainly rural areas of
  south central Garfield County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3760 11130 3775 11138 3792 11112 3760 11093
TIME...MOT...LOC 2255Z 243DEG 12KT 3772 11127 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church

1 follow-up statement

165 
WWUS55 KSLC 172320
SVSSLC

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

UTC017-172330-
/O.CAN.KSLC.SV.W.0074.000000T0000Z-210817T2345Z/
Garfield UT-
520 PM MDT Tue Aug 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL GARFIELD COUNTY
IS CANCELLED...
                
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 has been cancelled.

LAT...LON 3760 11130 3775 11138 3792 11112 3760 11093
TIME...MOT...LOC 2320Z 243DEG 12KT 3776 11117 

$$

Church

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 1:31 PM MDT	Special Weather Statement	SLC	Kane	44 min
Aug 17, 1:50 PM MDT	Severe Thunderstorm Warning	SLC	Garfield, Kane	20 min
Aug 17, 2:23 PM MDT	Severe Thunderstorm Warning	SLC	Beaver, Garfield, Piute	52 min
Aug 17, 2:50 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	3 hr
Aug 17, 3:14 PM MDT	Special Weather Statement	SLC	Juab	31 min
Aug 17, 3:20 PM MDT	Special Weather Statement	SLC	Tooele	25 min
Aug 17, 3:29 PM MDT	Severe Thunderstorm Warning	SLC	Sevier	46 min
Aug 17, 3:51 PM MDT	Severe Thunderstorm Warning	SLC	Tooele	24 min
Aug 17, 4:12 PM MDT	Severe Thunderstorm Warning Considerable damage threat	SLC	Tooele	48 min
Aug 17, 4:18 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Emery, Wayne	3 hr
Aug 17, 4:29 PM MDT	Severe Thunderstorm Warning	SLC	Tooele	46 min
Aug 17, 4:39 PM MDT	Severe Thunderstorm Warning Considerable damage threat	SLC	Millard	66 min
Aug 17, 4:53 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	3 hr
Aug 17, 5:00 PM MDT	Severe Thunderstorm Warning	SLC	Davis, Salt Lake, Tooele	30 min
Aug 17, 5:10 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Kane	4 hr
Aug 17, 5:12 PM MDT	Severe Thunderstorm Warning	SLC	Tooele	63 min
Aug 17, 5:30 PM MDT	Severe Thunderstorm Warning Considerable damage threat	SLC	Davis, Salt Lake	45 min
Aug 17, 5:37 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield, Kane	6 hr
Aug 17, 5:40 PM MDT	Severe Thunderstorm Warning	SLC	Millard	50 min
Aug 17, 5:48 PM MDT	Special Weather Statement	SLC	Sanpete	27 min

Nearby

Severe Thunderstorm Warnings in Utah, 2021 Every 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.