Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 66, NWS Salt Lake City, UT

August 14, 2021Washington County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 14, 2021, 7:01 PM MDT for Washington County, Utah. It was in force for 33 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
Aug 14, 2021, 7:01 PM MDT (01:01 UTC)
Expired
Aug 14, 2021, 7:34 PM MDT
In force
33 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Washington County, UT

The radar

The Cedar City radar (KICX), 83 km from the middle of the area, began a volume at 01:04 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

TimeReportWhereRemark
Aug 14, 7:12 PM MDTHAIL 1St George, UTVIEWER VIDEO SUBMITTED TO NEWS MEDIA WITH NICKEL AND QUARTER SIZED HAIL REPORTED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 00:00Z, 1.0 hours before the alert went out and 194 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 00:00Z on 2021-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1122 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 00:00Z on 2021-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 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
1122 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
3058 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

695 
WUUS55 KSLC 150101
SVRSLC
UTC053-150145-
/O.NEW.KSLC.SV.W.0066.210815T0101Z-210815T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
701 PM MDT Sat Aug 14 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  South central Washington County in southwestern Utah...

* Until 745 PM MDT

* At 701 PM MDT, a severe thunderstorm was located over St George, or
  20 miles northeast of Virgin River Gorge, moving southwest at 10
  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...
  St George, Washington, Santa Clara and Bloomington. 

This includes the following highways...
 Interstate 15 between mile markers 3 and 15.
 Utah Route 18 between mile markers 0 and 5.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3712 11368 3722 11350 3708 11339 3700 11350
      3700 11358
TIME...MOT...LOC 0101Z 054DEG 8KT 3709 11352 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Woodward
2 follow-up statements
515 
WWUS55 KSLC 150125
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
725 PM MDT Sat Aug 14 2021

UTC053-150145-
/O.CON.KSLC.SV.W.0066.000000T0000Z-210815T0145Z/
Washington UT-
725 PM MDT Sat Aug 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM MDT
FOR SOUTH CENTRAL WASHINGTON COUNTY...

At 725 PM MDT, a severe thunderstorm was located over St George, or
16 miles northeast of Virgin River Gorge, moving southwest 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...
St George, Washington, Santa Clara and Bloomington. 

This includes the following highways...
 Interstate 15 between mile markers 3 and 10.
 Utah Route 18 between mile markers 0 and 5.

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 3711 11367 3715 11362 3718 11357 3704 11345
      3700 11350 3700 11358
TIME...MOT...LOC 0125Z 054DEG 8KT 3706 11358 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Woodward
732 
WWUS55 KSLC 150134
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
734 PM MDT Sat Aug 14 2021

UTC053-150143-
/O.CAN.KSLC.SV.W.0066.000000T0000Z-210815T0145Z/
Washington UT-
734 PM MDT Sat Aug 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL WASHINGTON
COUNTY IS CANCELLED...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning has
been cancelled.

LAT...LON 3711 11367 3715 11362 3718 11357 3704 11345
      3700 11350 3700 11358
TIME...MOT...LOC 0132Z 054DEG 8KT 3705 11359 

$$

Woodward

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.