Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 65, NWS Salt Lake City, UT

August 14, 2021Washington County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Aug 14, 2021, 5:25 PM MDT for Washington County, Utah. It was in force for 36 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 14, 2021, 5:25 PM MDT (23:25 UTC)
Expired
Aug 14, 2021, 6:01 PM MDT
In force
36 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), 87 km from the middle of the area, began a volume at 23:24 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, 11.4 hours before the alert went out and 190 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 2021-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 356 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 2021-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
356 J/kg
Mixed-layer CIN
-261 J/kg
Mixed-layer LCL
2691 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

453 
WUUS55 KSLC 142325
SVRSLC
UTC053-150015-
/O.NEW.KSLC.SV.W.0065.210814T2325Z-210815T0015Z/

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

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northwestern Washington County in southwestern Utah...

* Until 615 PM MDT

* At 523 PM MDT, severe thunderstorms were located along a line
  extending from 8 miles east of Beaver Dam to 12 miles north of
  Dameron Valley, moving south at 15 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...
  Dameron Valley, Motoqua, Veyo and Goldstrike. 

This includes Utah Route 18 between mile markers 17 and 35.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move indoors immediately. Lightning is one of nature's leading 
killers. Remember, if you can hear thunder, you are close enough to 
be struck by lightning.

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3732 11405 3729 11353 3753 11354 3754 11394
TIME...MOT...LOC 2323Z 014DEG 14KT 3748 11390 3747 11361 

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

$$

Woodward
2 follow-up statements
175 
WWUS55 KSLC 142349
SVSSLC

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

UTC053-150015-
/O.CON.KSLC.SV.W.0065.000000T0000Z-210815T0015Z/
Washington UT-
549 PM MDT Sat Aug 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM MDT
FOR NORTHWESTERN WASHINGTON COUNTY...

At 548 PM MDT, severe thunderstorms were located along a line
extending from 10 miles southeast of Beaver Dam to near Dameron
Valley, moving south 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...
Dameron Valley, Motoqua, Veyo and Goldstrike. 

This includes Utah Route 18 between mile markers 17 and 31.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3729 11353 3732 11405 3751 11393 3747 11354
TIME...MOT...LOC 2348Z 014DEG 14KT 3739 11393 3738 11364 

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

$$

Woodward
007 
WWUS55 KSLC 150001
SVSSLC

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

UTC053-150010-
/O.CAN.KSLC.SV.W.0065.000000T0000Z-210815T0015Z/
Washington UT-
601 PM MDT Sat Aug 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN WASHINGTON COUNTY
IS CANCELLED...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds are
still possible with these thunderstorms.

LAT...LON 3729 11353 3732 11405 3751 11393 3747 11354
TIME...MOT...LOC 2356Z 014DEG 14KT 3736 11394 3735 11365 

$$

Woodward

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 14, 1:17 PM MDTFlash Flood WarningSLCEmery3 hr
Aug 14, 3:19 PM MDTSpecial Weather StatementSLCIron41 min
Aug 14, 3:35 PM MDTSpecial Weather StatementSLC40 min
Aug 14, 4:47 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Aug 14, 5:14 PM MDTSpecial Weather StatementSLCWashington46 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.