Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Salt Lake City, UT

July 18, 2021Beaver County, Iron County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jul 18, 2021, 4:31 PM MDT for Beaver County, Iron County, Utah. It was in force for 24 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 18, 2021, 4:31 PM MDT (22:31 UTC)
Expired
Jul 18, 2021, 4:55 PM MDT
In force
24 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Beaver County, UT, Iron County, UT

The radar

The Cedar City radar (KICX), 66 km from the middle of the area, began a volume at 22:32 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

Las Vegas, NV (KVEF), launched 12:00Z, 10.5 hours before the alert went out and 300 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, Las Vegas, NV at 12:00Z on 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 424 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, Las Vegas, NV at 12:00Z on 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939Sfc1 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
424 J/kg
Mixed-layer CIN
-164 J/kg
Mixed-layer LCL
2704 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

088 
WUUS55 KSLC 182231
SVRSLC
UTC001-021-182315-
/O.NEW.KSLC.SV.W.0018.210718T2231Z-210718T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
431 PM MDT Sun Jul 18 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  South central Beaver County in southern Utah...
  North central Iron County in southern Utah...

* Until 515 PM MDT

* At 431 PM MDT, a severe thunderstorm was located 19 miles south of
  Milford, moving west at 15 mph.

  HAZARD...60 mph wind gusts and penny size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Expect damage to roofs, siding, and trees. 

* Locations impacted include...
  Minersville.

This includes Utah Route 21 between mile markers 86 and 92.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3828 11294 3813 11281 3791 11307 3825 11329
TIME...MOT...LOC 2231Z 068DEG 13KT 3812 11302 

HAIL...0.75IN
WIND...60MPH
 
$$

Woodward
2 follow-up statements
578 
WWUS55 KSLC 182246
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
446 PM MDT Sun Jul 18 2021

UTC001-021-182315-
/O.CON.KSLC.SV.W.0018.000000T0000Z-210718T2315Z/
Beaver UT-Iron UT-
446 PM MDT Sun Jul 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM MDT
FOR SOUTH CENTRAL BEAVER AND NORTHEASTERN IRON COUNTIES...

At 445 PM MDT, a severe thunderstorm was located 16 miles south of
Milford, moving northwest at 10 mph.

HAZARD...60 mph wind gusts and penny size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Minersville.

This includes Utah Route 21 between mile markers 86 and 91.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3817 11286 3804 11302 3815 11323 3820 11326
      3826 11319 3828 11296
TIME...MOT...LOC 2245Z 133DEG 7KT 3816 11301 

HAIL...0.75IN
WIND...60MPH
 
$$

Woodward
396 
WWUS55 KSLC 182255
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
455 PM MDT Sun Jul 18 2021

UTC001-021-182305-
/O.CAN.KSLC.SV.W.0018.000000T0000Z-210718T2315Z/
Beaver UT-Iron UT-
455 PM MDT Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL BEAVER AND
NORTHEASTERN IRON COUNTIES IS CANCELLED...
                
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 has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 3817 11286 3804 11302 3815 11323 3820 11326
      3826 11319 3828 11296
TIME...MOT...LOC 2250Z 068DEG 13KT 3815 11305 

$$

Woodward

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 3:12 PM MDTSpecial Weather StatementSLCBeaver48 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.