Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 73, NWS Salt Lake City, UT

August 17, 2021Millard County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 17, 2021, 4:39 PM MDT for Millard County, Utah. It was in force for 66 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, 4:39 PM MDT (22:39 UTC)
Expired: Aug 17, 2021, 5:45 PM MDT
In force: 66 min
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Damage threat: Considerable
Hail: 1.75 in
Wind: 60.0 mph

County Millard County, UT

The radar

The Cedar City radar (KICX), 143 km from the middle of the area, began a volume at 22:39 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 12:00Z, 10.7 hours before the alert went out and 221 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: 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.

916 
WUUS55 KSLC 172239
SVRSLC
UTC027-172345-
/O.NEW.KSLC.SV.W.0073.210817T2239Z-210817T2345Z/

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

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Southeastern Millard County in central Utah...

* Until 545 PM MDT

* At 439 PM MDT, a severe thunderstorm was located 13 miles west of
  Kanosh, or 21 miles southwest of Fillmore, moving east at 20 mph.

  HAZARD...Golf 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. 

* Locations impacted include...
  Fillmore, Kanosh, Meadow, Hatton and Flowell. 

This includes Interstate 15 between mile markers 143 and 170.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3870 11279 3891 11285 3911 11235 3896 11223
      3874 11225
TIME...MOT...LOC 2239Z 248DEG 19KT 3882 11268 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church

2 follow-up statements

005 
WWUS55 KSLC 172301
SVSSLC

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

UTC027-172345-
/O.CON.KSLC.SV.W.0073.000000T0000Z-210817T2345Z/
Millard UT-
501 PM MDT Tue Aug 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM MDT
FOR SOUTHEASTERN MILLARD COUNTY...

At 500 PM MDT, a severe thunderstorm was located near Kanosh, or 13
miles southwest of Fillmore, moving east at 20 mph.

HAZARD...Golf 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. 

Locations impacted include...
Fillmore, Kanosh, Meadow, Hatton and Flowell. 

This includes Interstate 15 between mile markers 143 and 170.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3870 11279 3891 11285 3911 11235 3896 11223
      3874 11225
TIME...MOT...LOC 2300Z 248DEG 19KT 3886 11254 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Church

162 
WWUS55 KSLC 172342
SVSSLC

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

UTC027-172351-
/O.EXP.KSLC.SV.W.0073.000000T0000Z-210817T2345Z/
Millard UT-
542 PM MDT Tue Aug 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN MILLARD COUNTY
WILL EXPIRE AT 545 PM MDT...
    
This warning has been replaced by a new Severe Thunderstorm Warning. 

Remember, a Severe Thunderstorm Warning still remains in effect for
southeastern Millard County. 

LAT...LON 3870 11279 3891 11285 3911 11235 3896 11223
      3874 11225
TIME...MOT...LOC 2341Z 248DEG 19KT 3894 11228 

$$

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, 4:53 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield	3 hr
Aug 17, 4:56 PM MDT	Severe Thunderstorm Warning	SLC	Garfield	24 min
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.