Alert archive / Utah / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 69, NWS Salt Lake City, UT

August 4, 2011Utah County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 4, 2011, 5:27 PM MDT for Utah County, Utah. It was in force for 63 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
Aug 4, 2011, 5:27 PM MDT (23:27 UTC)
Expired
Aug 4, 2011, 6:30 PM MDT
In force
63 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon

County Utah County, UT

The radar

The Salt Lake City radar (KMTX), 140 km from the middle of the area, began a volume at 23:28 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, 11.5 hours before the alert went out and 71 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.

Skew-T log-pSkew-T log-p diagram, Salt Lake City I, UT at 12:00Z on 2011-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 228 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salt Lake City I, UT at 12:00Z on 2011-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
228 J/kg
Mixed-layer CIN
-245 J/kg
Mixed-layer LCL
1745 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

726 
WUUS55 KSLC 042327
SVRSLC
UTC049-050030-
/O.NEW.KSLC.SV.W.0069.110804T2327Z-110805T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
527 PM MDT THU AUG 4 2011

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL UTAH COUNTY IN UTAH

* UNTIL 630 PM MDT

* AT 520 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  SANTAQUIN...OR 7 MILES SOUTHWEST OF PAYSON...MOVING NORTHEAST AT 30
  MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  PAYSON... SALEM... SPANISH FORK... MAPLETON... SPRINGVILLE AND
  PROVO

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.

&&

LAT...LON 3995 11151 3984 11174 3994 11181 3991 11187
      3998 11199 4055 11158 4048 11157 4045 11161
      4036 11156 4034 11145 4030 11144 4028 11131
      4023 11127
TIME...MOT...LOC 2325Z 229DEG 27KT 3998 11178

$$

ROGOWSKI
4 follow-up statements
769 
WWUS55 KSLC 042342
SVSSLC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
542 PM MDT THU AUG 4 2011

UTC049-050030-
/O.CON.KSLC.SV.W.0069.000000T0000Z-110805T0030Z/
UTAH UT-
542 PM MDT THU AUG 4 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM MDT
FOR CENTRAL UTAH COUNTY...

AT 540 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER
SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS
WERE LOCATED ALONG A LINE EXTENDING FROM 9 MILES SOUTHWEST OF PROVO
TO SALEM TO 6 MILES SOUTHEAST OF SANTAQUIN...MOVING NORTHEAST AT 30
MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  SPANISH FORK... SPRINGVILLE... MAPLETON... PROVO... OREM... LINDON 
  AND MT TIMPANOGOS...AND INTERSTATE 15 BETWEEN PROVO AND SANTAQUIN.

LAT...LON 3995 11151 3985 11172 3994 11181 3999 11179
      4006 11194 4055 11158 4048 11157 4043 11161
      4036 11156 4034 11145 4030 11144 4028 11131
      4023 11127
TIME...MOT...LOC 2341Z 229DEG 27KT 4017 11179 4006 11167
          3999 11163 3990 11172

$$

ROGOWSKI
911 
WWUS55 KSLC 042354
SVSSLC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
554 PM MDT THU AUG 4 2011

UTC049-050030-
/O.CON.KSLC.SV.W.0069.000000T0000Z-110805T0030Z/
UTAH UT-
554 PM MDT THU AUG 4 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM MDT
FOR EASTERN UTAH COUNTY...

AT 551 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER
SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS
WERE LOCATED ALONG A LINE EXTENDING FROM PROVO TO SPANISH FORK TO 6
MILES SOUTH OF MAPLETON TO 7 MILES SOUTH OF SALEM...MOVING NORTHEAST
AT 30 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  MAPLETON... PROVO... OREM... LINDON AND MT TIMPANOGOS

LAT...LON 3995 11151 3992 11167 3999 11167 4007 11172
      4014 11187 4055 11158 4048 11157 4043 11161
      4036 11156 4034 11145 4030 11144 4028 11131
      4023 11127
TIME...MOT...LOC 2354Z 229DEG 27KT 4023 11170 4012 11158
          4005 11154 3996 11163

$$

ROGOWSKI
728 
WWUS55 KSLC 050004
SVSSLC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
604 PM MDT THU AUG 4 2011

UTC049-050030-
/O.CON.KSLC.SV.W.0069.000000T0000Z-110805T0030Z/
UTAH UT-
604 PM MDT THU AUG 4 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM MDT
FOR CENTRAL UTAH COUNTY...

AT 602 PM MDT... CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG
A LINE EXTENDING FROM OREM TO PROVO TO MAPLETON...MOVING NORTHEAST AT
30 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  INTERSTATE 15 BETWEEN OREM AND SPANISH FORK
  LINDON AND MT TIMPANOGOS

LAT...LON 3995 11151 3985 11172 3994 11181 3999 11179
      4006 11194 4055 11158 4048 11157 4043 11161
      4036 11156 4034 11145 4030 11144 4028 11131
      4023 11127
TIME...MOT...LOC 0004Z 241DEG 26KT 4030 11171 4025 11160
          4011 11146

$$

ROGOWSKI
254 
WWUS55 KSLC 050022
SVSSLC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
622 PM MDT THU AUG 4 2011

UTC049-050031-
/O.EXP.KSLC.SV.W.0069.000000T0000Z-110805T0030Z/
UTAH UT-
622 PM MDT THU AUG 4 2011

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL UTAH COUNTY WILL
EXPIRE AT 630 PM MDT...

THE STORMS CONTINUE TO WEAKEN AS THEY EXIT THE WARNED AREA. 
THEREFORE THE WARNING HAS BEEN ALLOWED TO EXPIRE.

LAT...LON 3995 11151 3985 11172 3994 11181 3999 11179
      4006 11194 4055 11158 4048 11157 4043 11161
      4036 11156 4034 11145 4030 11144 4028 11131
      4023 11127
TIME...MOT...LOC 0021Z 241DEG 26KT 4036 11157 4031 11146
          4017 11132

$$

ROGOWSKI

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 3, 6:26 PM MDTSpecial Weather StatementSLCPiute34 min
Aug 3, 8:54 PM MDTSpecial Weather StatementSLCPiute21 min
Aug 3, 10:26 PM MDTFlash Flood WarningSLCPiute, Sevier3 hr
Aug 4, 2:31 PM MDTSevere Thunderstorm WarningSLCJuab, Utah29 min
Aug 4, 3:14 PM MDTFlash Flood WarningSLCPiute3 hr
Aug 4, 3:27 PM MDTSevere Thunderstorm WarningSLCSalt Lake32 min
Aug 4, 3:28 PM MDTFlash Flood WarningSLCWayne4 hr
Aug 4, 3:31 PM MDTSevere Thunderstorm WarningSLCDuchesne59 min
Aug 4, 3:41 PM MDTSevere Thunderstorm WarningSLCUtah64 min
Aug 4, 3:44 PM MDTFlash Flood WarningSLCGarfield, Piute117 min
Aug 4, 3:58 PM MDTFlash Flood WarningSLCWayne2 hr
Aug 4, 4:07 PM MDTSevere Thunderstorm WarningSLCSalt Lake, Utah38 min
Aug 4, 4:11 PM MDTSevere Thunderstorm WarningSLCDuchesne, Wasatch36 min
Aug 4, 4:43 PM MDTSevere Thunderstorm WarningSLCJuab62 min
Aug 4, 4:56 PM MDTSevere Thunderstorm WarningSLCEmery34 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.