Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 111, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 12, 2021, 4:42 PM MDT for Box Elder 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
- Sep 12, 2021, 4:42 PM MDT (22:42 UTC)
- Expired
- Sep 12, 2021, 5:06 PM MDT
- In force
- 24 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County Box Elder County, UT
The radar
The Salt Lake City radar (KMTX), 76 km from the middle of the area, began a volume at 22:45 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
Elko, NV (KLKN), launched 12:00Z, 10.7 hours before the alert went out and 90 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
- 1594 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 10 m²/s²
- 0-3 km storm-relative helicity
- 135 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
802
WUUS55 KSLC 122242
SVRSLC
UTC003-122345-
/O.NEW.KSLC.SV.W.0111.210912T2242Z-210912T2345Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
442 PM MDT Sun Sep 12 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
Central Box Elder County in northern Utah...
* Until 545 PM MDT
* At 441 PM MDT, a severe thunderstorm was located 26 miles northwest
of Utah Test and Training Range North, or 32 miles east of
Montello, moving east at 30 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Great Salt Lake North of the Causeway.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4127 11365 4140 11366 4165 11294 4122 11284
TIME...MOT...LOC 2241Z 249DEG 27KT 4134 11356
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
CRK2 follow-up statements
858
WWUS55 KSLC 122256
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
456 PM MDT Sun Sep 12 2021
UTC003-122345-
/O.CON.KSLC.SV.W.0111.000000T0000Z-210912T2345Z/
Box Elder UT-
456 PM MDT Sun Sep 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM MDT
FOR CENTRAL BOX ELDER COUNTY...
At 456 PM MDT, a severe thunderstorm was located 25 miles northwest
of Utah Test and Training Range North, or 36 miles east of Montello,
moving east at 10 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Great Salt Lake North of the Causeway.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4127 11356 4143 11354 4165 11294 4122 11284
TIME...MOT...LOC 2256Z 251DEG 10KT 4136 11349
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
CRK893
WWUS55 KSLC 122306
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
506 PM MDT Sun Sep 12 2021
UTC003-122316-
/O.CAN.KSLC.SV.W.0111.000000T0000Z-210912T2345Z/
Box Elder UT-
506 PM MDT Sun Sep 12 2021
...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL BOX ELDER 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 4127 11356 4143 11354 4165 11294 4122 11284
TIME...MOT...LOC 2304Z 249DEG 27KT 4139 11339
$$
CRKThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 11, 6:19 PM MDT | Flash Flood Warning | SLC | Emery, Garfield, Wayne | 3 hr |
| Sep 11, 6:30 PM MDT | Special Weather Statement | SLC | Juab | 45 min |
| Sep 11, 7:16 PM MDT | Special Weather Statement | SLC | Juab | 44 min |
| Sep 11, 7:24 PM MDT | Special Weather Statement | SLC | 51 min | |
| Sep 11, 8:15 PM MDT | Flash Flood Warning | SLC | Garfield, Wayne | 3 hr |
| Sep 11, 8:22 PM MDT | Special Weather Statement | SLC | Sanpete | 38 min |
| Sep 11, 9:06 PM MDT | Special Weather Statement | SLC | Sanpete | 39 min |
| Sep 12, 3:29 PM MDT | Special Weather Statement | SLC | Box Elder | 46 min |
| Sep 12, 3:37 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 23 min |
| Sep 12, 3:54 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 51 min |
| Sep 12, 4:13 PM MDT | Special Weather Statement | SLC | Box Elder | 47 min |
| Sep 12, 4:31 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 44 min |
| Sep 12, 5:08 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 20 min |
| Sep 12, 5:14 PM MDT | Special Weather Statement | SLC | 46 min | |
| Sep 12, 5:54 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 51 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.