Alert archive / Utah / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 2, NWS Salt Lake City, UT

May 31, 2018Box Elder County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at May 31, 2018, 2:32 PM MDT for Box Elder County, Utah. It was in force for 58 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
May 31, 2018, 2:32 PM MDT (20:32 UTC)
Expired
May 31, 2018, 3:30 PM MDT
In force
58 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon
Hail
1.25 in
Wind
60.0 mph

County Box Elder County, UT

The radar

The Salt Lake City radar (KMTX), 124 km from the middle of the area, began a volume at 20:34 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

Elko, NV (KLKN), launched 12:00Z, 8.5 hours before the alert went out and 109 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, Elko, NV at 12:00Z on 2018-05-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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, Elko, NV at 12:00Z on 2018-05-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
16 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
1320 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

165 
WUUS55 KSLC 312032
SVRSLC
UTC003-312130-
/O.NEW.KSLC.SV.W.0002.180531T2032Z-180531T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Salt Lake City UT
232 PM MDT THU MAY 31 2018

The National Weather Service in Salt Lake City has issued a

* Severe Thunderstorm Warning for...
  Northwestern Box Elder County in northern Utah...

* Until 330 PM MDT

* At 231 PM MDT, a severe thunderstorm was located 26 miles north of
  Montello, moving northeast at 30 mph.

  HAZARD...60 mph wind gusts and half dollar size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Lynn, Etna, Yost and Grouse Creek. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4188 11338 4150 11404 4151 11405 4180 11404
      4199 11386 4199 11355
TIME...MOT...LOC 2031Z 224DEG 26KT 4163 11405 

HAIL...1.25IN
WIND...60MPH
 
$$

ES
2 follow-up statements
299 
WWUS55 KSLC 312104
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
304 PM MDT THU MAY 31 2018

UTC003-312130-
/O.CON.KSLC.SV.W.0002.000000T0000Z-180531T2130Z/
Box Elder UT-
304 PM MDT THU MAY 31 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM MDT
FOR NORTHWESTERN BOX ELDER COUNTY...

At 303 PM MDT, a severe thunderstorm was located 24 miles south of
Oakley Reservoir, moving northeast at 30 mph.

HAZARD...60 mph wind gusts and half dollar size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees. 

Locations impacted include...
Yost, Lynn and Grouse Creek. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4166 11387 4172 11404 4180 11404 4199 11386
      4199 11355 4197 11351
TIME...MOT...LOC 2103Z 209DEG 26KT 4182 11392 

HAIL...1.25IN
WIND...60MPH
 
$$

ES
466 
WWUS55 KSLC 312128
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
328 PM MDT THU MAY 31 2018

UTC003-312137-
/O.EXP.KSLC.SV.W.0002.000000T0000Z-180531T2130Z/
Box Elder UT-
328 PM MDT THU MAY 31 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN BOX ELDER COUNTY
WILL EXPIRE AT 330 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire.

LAT...LON 4166 11387 4172 11404 4180 11404 4199 11386
      4199 11355 4197 11351
TIME...MOT...LOC 2127Z 224DEG 26KT 4182 11392 

$$

ES

The office that day

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

IssuedProductOfficeCountiesLasted
May 30, 6:35 PM MDTSpecial Weather StatementSLCCache40 min
May 30, 7:06 PM MDTSpecial Weather StatementSLCCache54 min
May 30, 8:55 PM MDTSpecial Weather StatementSLCMorgan35 min
May 30, 8:57 PM MDTSpecial Weather StatementSLCSalt Lake33 min
May 30, 9:37 PM MDTSpecial Weather StatementSLCMorgan23 min
May 31, 4:21 PM MDTSevere Thunderstorm WarningSLCBox Elder24 min

Nearby

Severe Thunderstorm Warnings in Utah, 2018Every severe thunderstorm warning in 2018

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.