Alert archive / Utah / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 52, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 31, 2021, 3:16 PM MDT for Box Elder County, Cache County, Weber County, Utah. It was in force for 29 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
- Jul 31, 2021, 3:16 PM MDT (21:16 UTC)
- Expired
- Jul 31, 2021, 3:45 PM MDT
- In force
- 29 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
Counties Box Elder County, UT, Cache County, UT, Weber County, UT
The radar
The Salt Lake City radar (KMTX), 56 km from the middle of the area, began a volume at 21:21 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, 9.3 hours before the alert went out and 80 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
- 149 J/kg
- Mixed-layer CIN
- -128 J/kg
- Mixed-layer LCL
- 1716 m above ground
- 0-6 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 76 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
266
WUUS55 KSLC 312116
SVRSLC
UTC003-005-057-312145-
/O.NEW.KSLC.SV.W.0052.210731T2116Z-210731T2145Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
316 PM MDT Sat Jul 31 2021
The National Weather Service in Salt Lake City has issued a
* Severe Thunderstorm Warning for...
North central Weber County in northern Utah...
Southwestern Cache County in northern Utah...
East central Box Elder County in northern Utah...
* Until 345 PM MDT
* At 316 PM MDT, a severe thunderstorm was located near Mantua, or 8
miles east of Brigham City, moving southwest at 5 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...
Brigham City, North Ogden, Perry, Mantua, Paradise, Avon, Mantua
Reservoir and Liberty.
This includes Interstate 15 between mile markers 366 and 367.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4160 11180 4144 11170 4131 11193 4156 11208
TIME...MOT...LOC 2116Z 065DEG 5KT 4150 11184
HAIL...1.00IN
WIND...60MPH
$$
ND2 follow-up statements
958
WWUS55 KSLC 312129
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
329 PM MDT Sat Jul 31 2021
UTC003-005-057-312145-
/O.CON.KSLC.SV.W.0052.000000T0000Z-210731T2145Z/
Weber UT-Cache UT-Box Elder UT-
329 PM MDT Sat Jul 31 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM MDT
FOR NORTHERN WEBER...SOUTHWESTERN CACHE AND EAST CENTRAL BOX ELDER
COUNTIES...
At 328 PM MDT, a severe thunderstorm was located near Mantua, or 7
miles east of Brigham City, moving southwest at 5 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Brigham City, Perry, Mantua, Paradise, Avon and Mantua Reservoir.
This includes Interstate 15 between mile markers 366 and 367.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 4160 11180 4147 11173 4139 11197 4156 11208
TIME...MOT...LOC 2128Z 065DEG 5KT 4149 11186
HAIL...1.00IN
WIND...60MPH
$$
ND479
WWUS55 KSLC 312140
SVSSLC
Severe Weather Statement
National Weather Service Salt Lake City UT
340 PM MDT Sat Jul 31 2021
UTC003-005-057-312149-
/O.EXP.KSLC.SV.W.0052.000000T0000Z-210731T2145Z/
Weber UT-Cache UT-Box Elder UT-
340 PM MDT Sat Jul 31 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN WEBER...SOUTHWESTERN
CACHE AND EAST CENTRAL BOX ELDER COUNTIES WILL EXPIRE AT 345 PM
MDT...
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 will be allowed to expire. However small hail
and gusty winds are still possible with this thunderstorm.
LAT...LON 4160 11180 4147 11173 4139 11197 4156 11208
TIME...MOT...LOC 2139Z 065DEG 5KT 4148 11187
$$
NDThe office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 30, 7:17 PM MDT | Special Weather Statement | SLC | Beaver | 43 min |
| Jul 30, 7:31 PM MDT | Special Weather Statement | SLC | 44 min | |
| Jul 31, 12:31 PM MDT | Special Weather Statement | SLC | Summit | 44 min |
| Jul 31, 1:12 PM MDT | Special Weather Statement | SLC | Iron | 33 min |
| Jul 31, 1:23 PM MDT | Flash Flood Warning | SLC | Duchesne, Wasatch | 3 hr |
| Jul 31, 1:30 PM MDT | Severe Thunderstorm Warning | SLC | Iron, Washington | 30 min |
| Jul 31, 1:39 PM MDT | Special Weather Statement | SLC | Morgan | 36 min |
| Jul 31, 2:10 PM MDT | Special Weather Statement | SLC | Morgan | 50 min |
| Jul 31, 2:38 PM MDT | Special Weather Statement | SLC | Morgan | 37 min |
| Jul 31, 2:47 PM MDT | Severe Thunderstorm Warning | SLC | Morgan, Rich, Summit | 28 min |
| Jul 31, 2:52 PM MDT | Special Weather Statement | SLC | Rich | 23 min |
| Jul 31, 3:00 PM MDT | Areal Flood Advisory | SLC | Iron | 107 min |
| Jul 31, 3:10 PM MDT | Special Weather Statement | SLC | Morgan | 20 min |
| Jul 31, 3:35 PM MDT | Flash Flood Warning | SLC | Iron | 3 hr |
| Jul 31, 3:41 PM MDT | Special Weather Statement | SLC | Cache | 19 min |
| Jul 31, 4:00 PM MDT | Severe Thunderstorm Warning | SLC | Iron | 30 min |
| Jul 31, 4:06 PM MDT | Special Weather Statement | SLC | Beaver | 24 min |
| Jul 31, 4:10 PM MDT | Flash Flood Warning | SLC | Utah | 3 hr |
| Jul 31, 4:19 PM MDT | Flash Flood Warning | SLC | Duchesne | 3 hr |
| Jul 31, 4:39 PM MDT | Special Weather Statement | SLC | Rich | 66 min |
| Jul 31, 5:01 PM MDT | Special Weather Statement | SLC | 29 min | |
| Jul 31, 5:11 PM MDT | Flash Flood Warning | SLC | Washington | 3 hr |
| Jul 31, 5:25 PM MDT | Special Weather Statement | SLC | Juab | 35 min |
| Jul 31, 5:37 PM MDT | Special Weather Statement | SLC | Washington | 38 min |
| Jul 31, 5:39 PM MDT | Flash Flood Warning | SLC | Kane, Washington | 5 hr |
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.