Alert archive / Utah / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 5, NWS Salt Lake City, UT

May 16, 2021Box Elder County, Weber County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at May 16, 2021, 3:00 PM MDT for Box Elder County, Weber County, Utah. It was in force for 30 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: May 16, 2021, 3:00 PM MDT (21:00 UTC)
Expired: May 16, 2021, 3:30 PM MDT
In force: 30 min
Issued by: NWS Salt Lake City, UT
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Box Elder County, UT, Weber County, UT

The radar

The Salt Lake City radar (KMTX), 35 km from the middle of the area, began a volume at 21:02 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

Time	Report	Where	Remark
May 16, 3:27 PM MDT	HAIL 1	Plain City, UT

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 12:00Z, 9.0 hours before the alert went out and 67 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 528 J/kg
Mixed-layer CIN: -208 J/kg
Mixed-layer LCL: 1618 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 51 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

123 
WUUS55 KSLC 162100
SVRSLC
UTC003-057-162130-
/O.NEW.KSLC.SV.W.0005.210516T2100Z-210516T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
300 PM MDT Sun May 16 2021

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Central Weber County in northern Utah...
  East central Box Elder County in northern Utah...

* Until 330 PM MDT

* At 259 PM MDT, a severe thunderstorm was located over South
  Willard, or 9 miles south of Brigham City, moving northwest at 20
  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...
  Ogden, Brigham City, North Ogden, Hooper, Perry, Willard,
  Marriott-Slaterville, Bear River City, Corinne, South Willard, West
  Haven, Pleasant View, Farr West, Harrisville, Plain City, West
  Warren, Wilson, Warren, West Weber and Slaterville.

This includes Interstate 15 between mile markers 345 and 365.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4129 11189 4119 11210 4143 11238 4163 11214
      4141 11196
TIME...MOT...LOC 2059Z 131DEG 19KT 4137 11202 

HAIL...1.00IN
WIND...60MPH
 
$$

Webber

2 follow-up statements

500 
WWUS55 KSLC 162118
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
318 PM MDT Sun May 16 2021

UTC003-057-162130-
/O.CON.KSLC.SV.W.0005.000000T0000Z-210516T2130Z/
Weber UT-Box Elder UT-
318 PM MDT Sun May 16 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM MDT
FOR NORTH CENTRAL WEBER AND EAST CENTRAL BOX ELDER COUNTIES...

At 318 PM MDT, a severe thunderstorm was located near Willard, or 7
miles southwest of Brigham City, moving northwest at 20 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...
Brigham City, Perry, Willard, Marriott-Slaterville, Bear River City,
Corinne, South Willard, Pleasant View, Farr West, Harrisville, Plain
City and Warren.

This includes Interstate 15 between mile markers 348 and 365.

Weak rotation has been noted on radar over Willard Bay. A brief 
waterspout may be possible.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4129 11200 4125 11217 4143 11238 4163 11214
      4141 11196
TIME...MOT...LOC 2118Z 131DEG 19KT 4144 11212 

HAIL...1.00IN
WIND...60MPH
 
$$

Webber

385 
WWUS55 KSLC 162133
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
333 PM MDT Sun May 16 2021

UTC003-057-162142-
/O.EXP.KSLC.SV.W.0005.000000T0000Z-210516T2130Z/
Weber UT-Box Elder UT-
333 PM MDT Sun May 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL WEBER AND EAST
CENTRAL BOX ELDER COUNTIES HAS EXPIRED...
                
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 allowed to expire.  However heavy 
rain is still possible with this thunderstorm. A new Significant 
Weather Advisory has been issued for this storm and is valid until 
415 PM.

LAT...LON 4129 11200 4125 11217 4143 11238 4163 11214
      4141 11196
TIME...MOT...LOC 2132Z 131DEG 19KT 4149 11219 

$$

Webber

The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 6:30 PM MDT	Special Weather Statement	SLC		45 min
May 16, 1:07 PM MDT	Special Weather Statement	SLC	Salt Lake	38 min
May 16, 1:22 PM MDT	Severe Thunderstorm Warning	SLC	Davis, Salt Lake, Tooele	23 min
May 16, 1:52 PM MDT	Special Weather Statement	SLC	Davis	38 min
May 16, 1:55 PM MDT	Special Weather Statement	SLC	Salt Lake	35 min
May 16, 1:58 PM MDT	Special Weather Statement	SLC	Weber	47 min
May 16, 2:03 PM MDT	Severe Thunderstorm Warning	SLC	Morgan, Weber	27 min
May 16, 2:07 PM MDT	Special Weather Statement	SLC		38 min
May 16, 2:20 PM MDT	Special Weather Statement	SLC	Salt Lake	40 min
May 16, 2:29 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder, Weber	31 min
May 16, 2:31 PM MDT	Special Weather Statement	SLC	Davis	44 min
May 16, 2:50 PM MDT	Special Weather Statement	SLC		55 min
May 16, 3:04 PM MDT	Special Weather Statement	SLC	Tooele	41 min
May 16, 3:24 PM MDT	Severe Thunderstorm Warning	SLC	Tooele	51 min
May 16, 3:30 PM MDT	Special Weather Statement	SLC	Cache	45 min
May 16, 3:32 PM MDT	Special Weather Statement	SLC	Weber	43 min
May 16, 4:15 PM MDT	Special Weather Statement	SLC	Box Elder	45 min
May 16, 4:19 PM MDT	Special Weather Statement	SLC	Box Elder	41 min
May 16, 4:39 PM MDT	Special Weather Statement	SLC	Box Elder	51 min
May 16, 5:07 PM MDT	Special Weather Statement	SLC	Box Elder	53 min

Nearby

Severe Thunderstorm Warnings in Utah, 2021 Every 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.