Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 9, NWS Salt Lake City, UT

June 29, 2021Kane County, San Juan County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Jun 29, 2021, 4:03 PM MDT for Kane County, San Juan County, Utah. It was in force for 27 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
Jun 29, 2021, 4:03 PM MDT (22:03 UTC)
Expired
Jun 29, 2021, 4:30 PM MDT
In force
27 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Kane County, UT, San Juan County, UT

The radar

The Cedar City radar (KICX), 136 km from the middle of the area, began a volume at 22:05 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.1 hours before the alert went out and 209 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, Flgstf/Belemont, AZ at 12:00Z on 2021-06-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 225 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-06-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -75 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
225 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1570 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
-75 m²/s²
0-3 km storm-relative helicity
-28 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

451 
WUUS55 KSLC 292203
SVRSLC
UTC025-037-292230-
/O.NEW.KSLC.SV.W.0009.210629T2203Z-210629T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
403 PM MDT Tue Jun 29 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Southwestern San Juan County in southeastern Utah...
  South central Kane County in southern Utah...

* Until 430 PM MDT

* At 403 PM MDT, a severe thunderstorm was located near Lake Powell,
  or 14 miles northeast of Page, moving south at 10 mph.

  HAZARD...60 mph wind gusts. 

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Big Water and Lake Powell. 

This includes US Route 89 between mile markers 0 and 5.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. 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.

If on or near Lake Powell, get away from the water and move indoors 
or inside a vehicle. Remember, lightning can strike out to 15 miles 
from the parent thunderstorm. If you can hear thunder, you are close 
enough to be struck by lightning. Move to safe shelter now!  Do not 
be caught on the water in a thunderstorm.

&&

LAT...LON 3712 11165 3719 11124 3700 11116 3700 11163
TIME...MOT...LOC 2203Z 339DEG 9KT 3709 11135 

HAIL...<.75IN
WIND...60MPH
 
$$

MPS
2 follow-up statements
657 
WWUS55 KSLC 292218
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
418 PM MDT Tue Jun 29 2021

UTC025-037-292230-
/O.CON.KSLC.SV.W.0009.000000T0000Z-210629T2230Z/
San Juan UT-Kane UT-
418 PM MDT Tue Jun 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MDT
FOR SOUTHWESTERN SAN JUAN AND SOUTH CENTRAL KANE COUNTIES...

At 418 PM MDT, severe thunderstorms were located along a line
extending from Lake Powell to near Big Water, moving south at 20 mph.

HAZARD...60 mph wind gusts. 

SOURCE...Radar indicated. 

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

Locations impacted include...
Big Water and Lake Powell. 

This includes US Route 89 between mile markers 0 and 5.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with these storms.
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.

If on or near Lake Powell, get away from the water and move indoors 
or inside a vehicle. remember, lightning can strike out to 15 miles 
from the parent thunderstorm. If you can hear thunder, you are close 
enough to be struck by lightning. Move to safe shelter now!  Do not 
be caught on the water in a thunderstorm.

&&

LAT...LON 3712 11165 3719 11124 3700 11116 3700 11163
TIME...MOT...LOC 2218Z 349DEG 18KT 3705 11130 3704 11159 

HAIL...<.75IN
WIND...60MPH
 
$$

MPS
724 
WWUS55 KSLC 292230
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
430 PM MDT Tue Jun 29 2021

UTC025-037-292239-
/O.EXP.KSLC.SV.W.0009.000000T0000Z-210629T2230Z/
San Juan UT-Kane UT-
430 PM MDT Tue Jun 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN SAN JUAN AND
SOUTH CENTRAL KANE COUNTIES WILL EXPIRE AT 430 PM MDT...
            
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 will be allowed to expire.  However gusty
winds are still possible with these thunderstorms.

LAT...LON 3712 11165 3719 11124 3700 11116 3700 11163
TIME...MOT...LOC 2229Z 339DEG 9KT 3703 11129 3702 11158 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 1:53 PM MDTFlash Flood Warning Considerable damage threatSLCGarfield3 hr
Jun 29, 2:11 PM MDTFlash Flood Warning Considerable damage threatSLCKane, Washington3 hr
Jun 29, 2:14 PM MDTFlash Flood Warning Considerable damage threatSLCWashington3 hr
Jun 29, 3:09 PM MDTSpecial Weather StatementSLC36 min
Jun 29, 4:40 PM MDTFlash Flood Warning Considerable damage threatSLCKane3 hr

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.