Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 71, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 17, 2021, 4:12 PM MDT for Tooele County, Utah. It was in force for 48 min. 2 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, 4:12 PM MDT (22:12 UTC)
- Expired
- Aug 17, 2021, 5:00 PM MDT
- In force
- 48 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Hail
- 1.0 in
- Wind
- 70.0 mph
County Tooele County, UT
The radar
The Salt Lake City radar (KMTX), 69 km from the middle of the area, began a volume at 22:16 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 17, 4:20 PM MDT | TSTM WND GST 63 | Delle, UT | MESONET SITE NEAR DELLE |
| Aug 17, 4:20 PM MDT | TSTM WND GST 64 | 1 W Delle, UT | I-80 AT WEST DELLE |
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, 10.2 hours before the alert went out and 62 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.
- 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
The text
As transmitted.
707
WUUS55 KSLC 172212
SVRSLC
UTC045-172300-
/O.NEW.KSLC.SV.W.0071.210817T2212Z-210817T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
412 PM MDT Tue Aug 17 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
Northeastern Tooele County in northern Utah...
* Until 500 PM MDT
* At 412 PM MDT, a severe thunderstorm was located 9 miles north of
Skull Valley, or 16 miles west of Grantsville, moving east at 40
mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
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...
Tooele, Grantsville, Stansbury Park, Delle, Tooele Army Depot,
Skull Valley, Great Salt Lake South of the Causeway, Lake Point and
Erda.
This includes Interstate 80 in Utah between mile markers 57 and 101.
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.
&&
LAT...LON 4044 11290 4078 11299 4107 11249 4071 11222
4047 11220
TIME...MOT...LOC 2212Z 247DEG 34KT 4059 11278
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...70 MPH
$$
MPS1 follow-up statement
548
WWUS55 KSLC 172230
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
430 PM MDT Tue Aug 17 2021
UTC045-172300-
/O.CON.KSLC.SV.W.0071.000000T0000Z-210817T2300Z/
Tooele UT-
430 PM MDT Tue Aug 17 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM MDT
FOR NORTHEASTERN TOOELE COUNTY...
At 430 PM MDT, a severe thunderstorm was located 7 miles northwest of
Grantsville, moving northeast at 40 mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect considerable
tree damage. Wind damage is also likely to mobile homes,
roofs, and outbuildings.
Locations impacted include...
Tooele, Grantsville, Stansbury Park, Delle, Tooele Army Depot, Skull
Valley, Great Salt Lake South of the Causeway, Lake Point and Erda.
This includes Interstate 80 in Utah between mile markers 57 and 101.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 4044 11290 4078 11299 4107 11249 4071 11222
4047 11220
TIME...MOT...LOC 2230Z 247DEG 34KT 4066 11257
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...OBSERVED
MAX WIND GUST...70 MPH
$$
MPSThe 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 | 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, 4:18 PM MDT | Flash Flood Warning | 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 | SLC | Millard | 66 min |
| Aug 17, 4:53 PM MDT | Flash Flood Warning | 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 | 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 | SLC | Davis, Salt Lake | 45 min |
| Aug 17, 5:37 PM MDT | Flash Flood Warning | 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, 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.