Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 103, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 10, 2021, 6:06 PM MDT for Box Elder County, Weber County, Utah. It was in force for 39 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
- Sep 10, 2021, 6:06 PM MDT (00:06 UTC)
- Expired
- Sep 10, 2021, 6:45 PM MDT
- In force
- 39 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, Weber County, UT
The radar
The Salt Lake City radar (KMTX), 48 km from the middle of the area, began a volume at 00:06 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 00:00Z, 0.1 hours before the alert went out and 95 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
- 430 J/kg
- Mixed-layer CIN
- -39 J/kg
- Mixed-layer LCL
- 3241 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 128 m²/s²
- 0-3 km storm-relative helicity
- 161 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.2
The text
As transmitted.
760
WUUS55 KSLC 110006
SVRSLC
UTC003-057-110045-
/O.NEW.KSLC.SV.W.0103.210911T0006Z-210911T0045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
606 PM MDT Fri Sep 10 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
West central Weber County in northern Utah...
Eastern Box Elder County in northern Utah...
* Until 645 PM MDT
* At 604 PM MDT, strong outflow winds associated with strong
thunderstorms were located along a line extending from 10 miles
east of Great Salt Lake North of the Causeway to 10 miles north of
Great Salt Lake South of the Causeway, moving northeast at 35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Brigham City, Tremonton, Perry, Willard, Bear River City, Corinne,
Plymouth, South Willard, Riverside, Great Salt Lake South of the
Causeway, Great Salt Lake North of the Causeway, Pleasant View,
Farr West, Plain City, Garland, Honeyville, Elwood, Fielding,
Deweyville and Collinston.
This includes the following highways...
Interstate 15 between mile markers 351 and 391.
Interstate 84 between mile markers 34 and 42.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Wind damage with these storms will occur before any rain or
lightning. Do not wait for the sound of thunder before taking cover.
SEEK SHELTER IMMEDIATELY inside a sturdy structure and stay away from
windows.
&&
LAT...LON 4189 11208 4184 11205 4178 11205 4172 11208
4166 11205 4164 11206 4151 11198 4145 11203
4138 11203 4135 11198 4110 11244 4155 11267
4190 11213
TIME...MOT...LOC 0004Z 231DEG 31KT 4147 11260 4115 11243
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Webber2 follow-up statements
081
WWUS55 KSLC 110030
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
630 PM MDT Fri Sep 10 2021
UTC003-057-110045-
/O.CON.KSLC.SV.W.0103.000000T0000Z-210911T0045Z/
Weber UT-Box Elder UT-
630 PM MDT Fri Sep 10 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM MDT
FOR WEST CENTRAL WEBER AND NORTHEASTERN BOX ELDER COUNTIES...
At 629 PM MDT, strong outflow winds associated with thunderstorms
were located along a line extending from 12 miles south of Howell to
8 miles northwest of Hooper, moving northeast at 35 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Brigham City, Tremonton, Perry, Willard, Bear River City, Corinne,
Plymouth, South Willard, Riverside, Pleasant View, Farr West, Plain
City, Garland, Honeyville, Elwood, Fielding, Deweyville, Collinston,
Penrose and Bothwell.
This includes the following highways...
Interstate 15 between mile markers 351 and 391.
Interstate 84 between mile markers 34 and 42.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Wind damage with these storms will occur before any rain or
lightning. Do not wait for the sound of thunder before taking cover.
SEEK SHELTER IMMEDIATELY inside a sturdy structure and stay away from
windows.
&&
LAT...LON 4189 11208 4184 11205 4178 11205 4172 11208
4166 11205 4164 11206 4151 11198 4145 11203
4138 11203 4135 11198 4117 11232 4159 11261
4190 11213
TIME...MOT...LOC 0029Z 231DEG 31KT 4160 11239 4128 11222
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
Webber336
WWUS55 KSLC 110044
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
644 PM MDT Fri Sep 10 2021
UTC003-057-110052-
/O.EXP.KSLC.SV.W.0103.000000T0000Z-210911T0045Z/
Weber UT-Box Elder UT-
644 PM MDT Fri Sep 10 2021
...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL WEBER AND
NORTHEASTERN BOX ELDER COUNTIES WILL EXPIRE AT 645 PM MDT...
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire. A special weather
statement is now in effect for this line, with gusts to 55 mph
possible.
LAT...LON 4189 11208 4184 11205 4178 11205 4172 11208
4166 11205 4164 11206 4151 11198 4145 11203
4138 11203 4135 11198 4117 11232 4159 11261
4190 11213
TIME...MOT...LOC 0042Z 231DEG 31KT 4167 11227 4135 11210
$$
CRKThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 10, 6:20 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Morgan, Weber | 25 min |
| Sep 10, 6:42 PM MDT | Special Weather Statement | SLC | Morgan, Weber | 33 min |
| Sep 10, 6:42 PM MDT | Special Weather Statement | SLC | Davis | 33 min |
| Sep 10, 6:50 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Salt Lake, Tooele | 25 min |
| Sep 10, 7:10 PM MDT | Special Weather Statement | SLC | Salt Lake, Utah | 50 min |
| Sep 10, 7:10 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Morgan, Salt Lake, Weber | 35 min |
| Sep 10, 7:16 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Salt Lake | 29 min |
| Sep 10, 7:24 PM MDT | Special Weather Statement | SLC | Rich | 51 min |
| Sep 10, 7:24 PM MDT | Special Weather Statement | SLC | Cache | 51 min |
| Sep 10, 7:38 PM MDT | Special Weather Statement | SLC | Cache, Morgan, Rich, Weber | 52 min |
| Sep 11, 12:50 PM MDT | Flash Flood Warning | SLC | Wayne | 3 hr |
| Sep 11, 12:54 PM MDT | Special Weather Statement | SLC | Carbon | 51 min |
| Sep 11, 1:39 PM MDT | Special Weather Statement | SLC | Duchesne | 51 min |
| Sep 11, 1:40 PM MDT | Flash Flood Warning | SLC | Carbon | 3 hr |
| Sep 11, 3:17 PM MDT | Special Weather Statement | SLC | Duchesne | 43 min |
| Sep 11, 4:25 PM MDT | Special Weather Statement | SLC | Millard | 35 min |
| Sep 11, 5:10 PM MDT | Special Weather Statement | SLC | Juab | 35 min |
| Sep 11, 5:19 PM MDT | Special Weather Statement | SLC | Millard | 26 min |
| Sep 11, 5:44 PM MDT | Special Weather Statement | SLC | Millard | 46 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.