Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 88, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 21, 2021, 5:52 PM MDT for Box Elder County, Cache County, Utah. It was in force for 38 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 21, 2021, 5:52 PM MDT (23:52 UTC)
- Expired
- Aug 21, 2021, 6:30 PM MDT
- In force
- 38 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
Counties Box Elder County, UT, Cache County, UT
The radar
The Salt Lake City radar (KMTX), 93 km from the middle of the area, began a volume at 23:56 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, 11.9 hours before the alert went out and 121 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
- 77 J/kg
- Mixed-layer CIN
- -271 J/kg
- Mixed-layer LCL
- 2167 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 239 m²/s²
- 0-3 km storm-relative helicity
- 260 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
939
WUUS55 KSLC 212352
SVRSLC
UTC003-005-220030-
/O.NEW.KSLC.SV.W.0088.210821T2352Z-210822T0030Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
552 PM MDT Sat Aug 21 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
Northern Cache County in northern Utah...
Northeastern Box Elder County in northern Utah...
* Until 630 PM MDT
* At 552 PM MDT, a severe thunderstorm was located over Tremonton,
moving northeast at 50 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Logan, Tremonton, Cache, Smithfield, Hyrum, Wellsville, Lewiston,
Bear River City, Clarkston, Trenton, Plymouth, Howell, Utah State
University, Benson, Peter, Riverside, North Logan, Providence,
Nibley and Hyde Park.
This includes the following highways...
Interstate 15 between mile markers 371 and 394.
Interstate 84 between mile markers 23 and 42.
US Route 89 between mile markers 459 and 490.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4198 11149 4192 11148 4191 11151 4185 11151
4180 11145 4173 11144 4173 11142 4169 11143
4156 11244 4186 11246 4200 11174 4200 11151
TIME...MOT...LOC 2352Z 242DEG 45KT 4168 11213
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Webber1 follow-up statement
707
WWUS55 KSLC 220019
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
619 PM MDT Sat Aug 21 2021
UTC003-005-220030-
/O.CON.KSLC.SV.W.0088.000000T0000Z-210822T0030Z/
Cache UT-Box Elder UT-
619 PM MDT Sat Aug 21 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM MDT
FOR NORTHERN CACHE AND NORTHEASTERN BOX ELDER COUNTIES...
At 618 PM MDT, a severe thunderstorm was located near Smithfield, or
8 miles northeast of Logan, moving east at 50 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Logan, Tremonton, Cache, Smithfield, Hyrum, Wellsville, Lewiston,
Bear River City, Clarkston, Trenton, Plymouth, Howell, Utah State
University, Benson, Peter, Riverside, North Logan, Providence, Nibley
and Hyde Park.
This includes the following highways...
Interstate 15 between mile markers 371 and 394.
Interstate 84 between mile markers 23 and 42.
US Route 89 between mile markers 459 and 490.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4198 11149 4192 11148 4191 11151 4185 11151
4180 11145 4173 11144 4173 11142 4169 11143
4156 11244 4186 11246 4200 11174 4200 11151
TIME...MOT...LOC 0018Z 270DEG 45KT 4182 11173
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
WebberThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 1:25 PM MDT | Special Weather Statement | SLC | Rich | 50 min |
| Aug 21, 3:14 PM MDT | Special Weather Statement | SLC | Box Elder | 61 min |
| Aug 21, 4:31 PM MDT | Special Weather Statement | SLC | Tooele | 59 min |
| Aug 21, 4:34 PM MDT | Special Weather Statement | SLC | Cache | 56 min |
| Aug 21, 5:10 PM MDT | Special Weather Statement | SLC | Davis | 20 min |
| Aug 21, 5:19 PM MDT | Special Weather Statement | SLC | Davis | 26 min |
| Aug 21, 5:27 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder, Cache, Davis, Morgan, Weber | 48 min |
| Aug 21, 5:42 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Salt Lake, Tooele | 33 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.