Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 98, NWS Salt Lake City, UT

September 2, 2021Davis County, Morgan County, Salt Lake County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 2, 2021, 6:29 PM MDT for Davis County, Morgan County, Salt Lake County, Utah. It was in force for 31 min. 2 reports 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
Sep 2, 2021, 6:29 PM MDT (00:29 UTC)
Expired
Sep 2, 2021, 7:00 PM MDT
In force
31 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Davis County, UT, Morgan County, UT, Salt Lake County, UT

The radar

The Salt Lake City radar (KMTX), 55 km from the middle of the area, began a volume at 00:31 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
Sep 2, 6:31 PM MDTHAIL 0.75Woods Cross, UT
Sep 2, 6:45 PM MDTHAIL 0.75Centerville, UTTIME ESTIMATED BY RADAR

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

The nearest sounding before it

Salt Lake City I, UT (KSLC), launched 00:00Z, 0.5 hours before the alert went out and 16 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 00:00Z on 2021-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 942 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 00:00Z on 2021-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939587897Sfc1 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
942 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
2400 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.6

Open this sounding in Storm Lab

The text

As transmitted.

988 
WUUS55 KSLC 030029
SVRSLC
UTC011-029-035-030100-
/O.NEW.KSLC.SV.W.0098.210903T0029Z-210903T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
629 PM MDT Thu Sep 2 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northwestern Salt Lake County in northern Utah...
  Eastern Davis County in northern Utah...
  West central Morgan County in northern Utah...

* Until 700 PM MDT

* At 628 PM MDT, a severe thunderstorm was located 7 miles west of
  West Bountiful, or 10 miles west of Bountiful, moving northeast at
  20 mph.

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

  SOURCE...Radar indicated. 

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

* Locations impacted include...
  Salt Lake City, Layton, Bountiful, Farmington, Kaysville, North
  Salt Lake, Centerville, Woods Cross, South Weber, West Bountiful,
  Salt Lake City International Airport, Great Salt Lake South of the
  Causeway, Fruit Heights, East Layton and Antelope Island State
  Park.

This includes the following highways...
 Interstate 15 between mile markers 314 and 332.
 Interstate 80 in Utah between mile markers 112 and 113.

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 the Great Salt Lake, 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.

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

&&

LAT...LON 4076 11205 4092 11229 4113 11191 4096 11169
TIME...MOT...LOC 0028Z 225DEG 19KT 4089 11206 

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

$$

MT
2 follow-up statements
386 
WWUS55 KSLC 030046
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
646 PM MDT Thu Sep 2 2021

UTC011-029-035-030100-
/O.CON.KSLC.SV.W.0098.000000T0000Z-210903T0100Z/
Salt Lake UT-Davis UT-Morgan UT-
646 PM MDT Thu Sep 2 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM MDT
FOR NORTHWESTERN SALT LAKE...EASTERN DAVIS AND WEST CENTRAL MORGAN
COUNTIES...

At 646 PM MDT, a severe thunderstorm was located near West Bountiful,
or near Farmington, moving northeast at 20 mph.

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

SOURCE...Radar indicated. 

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

Locations impacted include...
Salt Lake City, Layton, Bountiful, Farmington, Kaysville, North Salt
Lake, Centerville, Woods Cross, South Weber, West Bountiful, Salt
Lake City International Airport, Great Salt Lake South of the
Causeway, Fruit Heights, East Layton and Antelope Island State Park.

This includes the following highways...
 Interstate 15 between mile markers 314 and 332.
 Interstate 80 in Utah between mile markers 112 and 113.

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 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.

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

&&

LAT...LON 4076 11205 4092 11229 4113 11191 4096 11169
TIME...MOT...LOC 0046Z 225DEG 19KT 4096 11197 

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

$$

MT
926 
WWUS55 KSLC 030057
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
657 PM MDT Thu Sep 2 2021

UTC011-029-035-030105-
/O.EXP.KSLC.SV.W.0098.000000T0000Z-210903T0100Z/
Salt Lake UT-Davis UT-Morgan UT-
657 PM MDT Thu Sep 2 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN SALT LAKE...
EASTERN DAVIS AND WEST CENTRAL MORGAN COUNTIES WILL EXPIRE AT 700 PM
MDT...
                
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 will be allowed to expire.  However heavy 
rain, strong gusty winds to 50 mph, and small hail are still 
possible with this thunderstorm, so a Special Weather Statement will 
be in effect for this storm until 730 PM MDT. 

LAT...LON 4076 11205 4092 11229 4113 11191 4096 11169
TIME...MOT...LOC 0055Z 225DEG 19KT 4099 11193 

$$

MT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 2, 6:13 PM MDTSpecial Weather StatementSLCSalt Lake32 min
Sep 2, 6:59 PM MDTSpecial Weather StatementSLCMorgan31 min
Sep 2, 7:31 PM MDTSpecial Weather StatementSLCSummit29 min
Sep 2, 7:49 PM MDTSevere Thunderstorm WarningSLCRich, Summit26 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.