Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 109, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 12, 2021, 3:54 PM MDT for Box Elder County, Utah. It was in force for 51 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, 3:54 PM MDT (21:54 UTC)
- Expired
- Sep 12, 2021, 4:45 PM MDT
- In force
- 51 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Hail
- 1.25 in
- Wind
- 60.0 mph
County Box Elder County, UT
The radar
The Salt Lake City radar (KMTX), 105 km from the middle of the area, began a volume at 21:56 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
Elko, NV (KLKN), launched 12:00Z, 9.9 hours before the alert went out and 68 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.
929
WUUS55 KSLC 122154
SVRSLC
UTC003-122245-
/O.NEW.KSLC.SV.W.0109.210912T2154Z-210912T2245Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
354 PM MDT Sun Sep 12 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
Southwestern Box Elder County in northern Utah...
* Until 445 PM MDT
* At 353 PM MDT, a severe thunderstorm was located 10 miles east of
Montello, moving east at 30 mph. Another severe thunderstorm was
located near Lucin moving east at 30 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Lucin.
This includes Utah Route 30 between mile markers 1 and 28.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4161 11342 4117 11324 4117 11403 4120 11404
4137 11404
TIME...MOT...LOC 2153Z 249DEG 27KT 4129 11398
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
CRK2 follow-up statements
016
WWUS55 KSLC 122215
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
415 PM MDT Sun Sep 12 2021
UTC003-122245-
/O.CON.KSLC.SV.W.0109.000000T0000Z-210912T2245Z/
Box Elder UT-
415 PM MDT Sun Sep 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM MDT
FOR SOUTHWESTERN BOX ELDER COUNTY...
At 415 PM MDT, a severe thunderstorm was located 22 miles east of
Montello, moving east at 30 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Lucin.
This includes Utah Route 30 between mile markers 6 and 28.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4161 11342 4117 11324 4122 11384 4125 11390
4141 11394
TIME...MOT...LOC 2215Z 249DEG 27KT 4135 11377
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
CRK226
WWUS55 KSLC 122232
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
432 PM MDT Sun Sep 12 2021
UTC003-122245-
/O.CON.KSLC.SV.W.0109.000000T0000Z-210912T2245Z/
Box Elder UT-
432 PM MDT Sun Sep 12 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM MDT
FOR WEST CENTRAL BOX ELDER COUNTY...
At 432 PM MDT, a severe thunderstorm was located 27 miles east of
Montello, moving east at 25 mph.
HAZARD...60 mph wind gusts and half dollar size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
This severe thunderstorm will remain over mainly rural areas of west
central Box Elder County.
This includes Utah Route 30 between mile markers 21 and 22.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4161 11342 4124 11327 4124 11370 4142 11372
TIME...MOT...LOC 2232Z 265DEG 23KT 4131 11365
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
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, 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, 4:42 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 24 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.