Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 112, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 12, 2021, 5:08 PM MDT for Box Elder County, Utah. It was in force for 20 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, 5:08 PM MDT (23:08 UTC)
- Expired
- Sep 12, 2021, 5:28 PM MDT
- In force
- 20 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), 74 km from the middle of the area, began a volume at 23:07 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, 11.1 hours before the alert went out and 138 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
- 108 J/kg
- Mixed-layer CIN
- -195 J/kg
- Mixed-layer LCL
- 1716 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 76 m²/s²
- 0-3 km storm-relative helicity
- 124 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
756
WUUS55 KSLC 122308
SVRSLC
UTC003-122345-
/O.NEW.KSLC.SV.W.0112.210912T2308Z-210912T2345Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
508 PM MDT Sun Sep 12 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
North central Box Elder County in northern Utah...
* Until 545 PM MDT
* At 508 PM MDT, a severe thunderstorm was located near Snowville,
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...
Snowville.
This includes the following highways...
Interstate 84 between mile markers 0 and 22.
Utah Route 30 between mile markers 87 and 90.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 4185 11235 4191 11282 4200 11284 4200 11235
TIME...MOT...LOC 2308Z 270DEG 26KT 4199 11277
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
CRK1 follow-up statement
773
WWUS55 KSLC 122328
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
528 PM MDT Sun Sep 12 2021
UTC003-122338-
/O.CAN.KSLC.SV.W.0112.000000T0000Z-210912T2345Z/
Box Elder UT-
528 PM MDT Sun Sep 12 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL BOX ELDER COUNTY
IS CANCELLED...
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.
LAT...LON 4185 11235 4191 11282 4200 11284 4200 11235
TIME...MOT...LOC 2326Z 270DEG 26KT 4199 11257
$$
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, 4:42 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 24 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.