Alert archive / Utah / Severe Thunderstorm Warnings in 2011
Severe Thunderstorm Warning 2, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at Apr 21, 2011, 11:12 AM MDT for Box Elder County, Tooele County, Utah. It was in force for 48 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Apr 21, 2011, 11:12 AM MDT (17:12 UTC)
- Expired
- Apr 21, 2011, 12:00 PM MDT
- In force
- 48 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Storm-based polygon
Counties Box Elder County, UT, Tooele County, UT
The radar
The Salt Lake City radar (KMTX), 84 km from the middle of the area, began a volume at 17:12 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Apr 21, 11:50 AM MDT | TSTM WND GST 58 | 15 Nne Knolls, UT | DIDDLE KNOLL SENSOR |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Elko, NV (KLKN), launched 12:00Z, 5.2 hours before the alert went out and 76 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
- 1727 m above ground
- 0-6 km bulk shear
- 62 kt
- 0-1 km storm-relative helicity
- 112 m²/s²
- 0-3 km storm-relative helicity
- 193 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
644 WUUS55 KSLC 211712 SVRSLC UTC003-045-211800- /O.NEW.KSLC.SV.W.0002.110421T1712Z-110421T1800Z/ BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE SALT LAKE CITY UT 1112 AM MDT THU APR 21 2011 THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTH CENTRAL BOX ELDER COUNTY IN UTAH NORTH CENTRAL TOOELE COUNTY IN UTAH * UNTIL NOON MDT * AT 1107 AM MDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DESTRUCTIVE WINDS IN EXCESS OF 70 MPH. THIS STORM WAS LOCATED 10 MILES SOUTH OF BONNEVILLE SALT FLATS...OR 14 MILES EAST OF WENDOVER...MOVING NORTHEAST AT 50 MPH. * LOCATIONS IN THE WARNING INCLUDE... KNOLLS INTERSTATE 80 FROM THE UTAH NEVADA BORDER EAST TO NEAR CLIVE PRECAUTIONARY/PREPAREDNESS ACTIONS... THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER... PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS. DAMAGING WINDS UP TO 71 MPH WERE REPORTED IN WENDOVER WITH THIS STORM. THIS IS A DANGEROUS STORM...SEEK SAFE SHELTER AND STAY AWAY FROM WINDOWS! && LAT...LON 4120 11302 4053 11282 4052 11383 4092 11381 TIME...MOT...LOC 1711Z 246DEG 42KT 4072 11370 $$ CRK
2 follow-up statements
814 WWUS55 KSLC 211737 SVSSLC SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SALT LAKE CITY UT 1137 AM MDT THU APR 21 2011 UTC003-045-211800- /O.CON.KSLC.SV.W.0002.000000T0000Z-110421T1800Z/ TOOELE UT-BOX ELDER UT- 1137 AM MDT THU APR 21 2011 ...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL NOON MDT FOR SOUTH CENTRAL BOX ELDER AND NORTH CENTRAL TOOELE COUNTIES... AT 1133 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 9 MILES NORTHWEST OF KNOLLS...OR ABOUT 34 MILES EAST OF WENDOVER...MOVING NORTHEAST AT 50 MPH. * LOCATIONS IN THE WARNING INCLUDE... RURAL NORTHERN TOOELE COUNTY AND RURAL SOUTHERN BOX ELDER COUNTY INTERSTATE 80 FROM NEAR THE BONNEVILLE SALT FLATS TO WEST OF DELLE PRECAUTIONARY/PREPAREDNESS ACTIONS... DAMAGING WINDS UP TO 71 MPH WERE REPORTED IN WENDOVER WITH THIS STORM. THIS IS A DANGEROUS STORM...SEEK SAFE SHELTER AND STAY AWAY FROM WINDOWS! && LAT...LON 4053 11361 4092 11381 4120 11302 4053 11282 TIME...MOT...LOC 1737Z 246DEG 42KT 4084 11333 $$ CRK
080 WWUS55 KSLC 211756 SVSSLC SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE SALT LAKE CITY UT 1156 AM MDT THU APR 21 2011 UTC003-045-211806- /O.EXP.KSLC.SV.W.0002.000000T0000Z-110421T1800Z/ TOOELE UT-BOX ELDER UT- 1156 AM MDT THU APR 21 2011 ...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL BOX ELDER AND NORTH CENTRAL TOOELE COUNTIES WILL EXPIRE AT NOON MDT... THE STORM HAS WEAKENED AND IS NO LONGER SEVERE. THEREFORE THE WARNING HAS BEEN ALLOWED TO EXPIRE. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED FOR THIS LINE OF THUNDERSTORMS. STRONG WINDS UP TO 55 MPH REMAIN POSSIBLE AS THE LINE CONTINUES TO THE EAST. LAT...LON 4053 11361 4092 11381 4120 11302 4053 11282 TIME...MOT...LOC 1756Z 246DEG 42KT 4093 11306 $$ CRK
The office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 21, 10:41 AM MDT | Wind Advisory | SLC | 10 hr | |
| Apr 21, 11:03 AM MDT | Special Weather Statement | SLC | Tooele | 57 min |
| Apr 21, 11:39 AM MDT | Special Weather Statement | SLC | Rich | 51 min |
| Apr 21, 11:55 AM MDT | Special Weather Statement | SLC | Tooele | 50 min |
| Apr 21, 12:12 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder, Tooele | 48 min |
| Apr 21, 12:25 PM MDT | High Wind Warning | SLC | 6 hr | |
| Apr 21, 12:29 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder | 46 min |
| Apr 21, 12:33 PM MDT | Special Weather Statement | SLC | Rich | 27 min |
| Apr 21, 12:37 PM MDT | Severe Thunderstorm Warning | SLC | Juab, Tooele | 23 min |
| Apr 21, 12:43 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Weber | 17 min |
| Apr 21, 12:52 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder, Cache, Davis, Morgan, Tooele, Weber | 23 min |
| Apr 21, 12:55 PM MDT | Severe Thunderstorm Warning | SLC | Juab, Morgan, Salt Lake, Tooele, Utah | 35 min |
| Apr 21, 1:12 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder, Cache, Davis, Morgan, Salt Lake, Tooele and 1 more | 48 min |
| Apr 21, 1:24 PM MDT | Severe Thunderstorm Warning | SLC | Juab, Salt Lake, Tooele, Utah | 36 min |
| Apr 21, 1:45 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder, Cache, Davis, Morgan, Rich, Salt Lake and 3 more | 30 min |
| Apr 21, 1:55 PM MDT | Special Weather Statement | SLC | Utah, Wasatch | 50 min |
| Apr 21, 2:10 PM MDT | Special Weather Statement | SLC | Carbon | 50 min |
| Apr 21, 2:14 PM MDT | Severe Thunderstorm Warning | SLC | Cache, Morgan, Rich, Summit | 46 min |
| Apr 21, 2:16 PM MDT | Severe Thunderstorm Warning | SLC | Carbon | 29 min |
| Apr 21, 2:41 PM MDT | Severe Thunderstorm Warning | SLC | Rich | 35 min |
| Apr 21, 2:44 PM MDT | Severe Thunderstorm Warning | SLC | Carbon | 16 min |
Nearby
Severe Thunderstorm Warnings in Utah, 2011Every severe thunderstorm warning in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.