Alert archive / Utah / Special Weather Statements in 2021

Special Weather Statement, NWS Salt Lake City, UT

September 12, 2021

NWS Salt Lake City, UT issued this special weather statement at Sep 12, 2021, 5:14 PM MDT. It was in force for 46 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: Sep 12, 2021, 5:14 PM MDT (23:14 UTC)
Expired: Sep 12, 2021, 6:00 PM MDT
In force: 46 min
Issued by: NWS Salt Lake City, UT
Hail: 0.50 in
Wind: 55

The radar

The Salt Lake City radar (KMTX), 126 km from the middle of the area, began a volume at 23:13 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, 11.2 hours before the alert went out and 108 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1594 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 135 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Salt Lake City, UT wrote its last area forecast discussion before this special weather statement went out at Sep 12, 4:25 PM MDT, 49 minutes earlier.

Area forecast discussion, Sep 12, 4:25 PM MDT, 49 minutes before

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In the hours before

Special weather statement, Sep 12, 3:29 PM MDT, 1 hour 45 minutes before

Special Weather Statement
National Weather Service Salt Lake City UT
329 PM MDT Sun Sep 12 2021

UTZ101-122215-
Great Salt Lake Desert and Mountains UT-
329 PM MDT Sun Sep 12 2021

...A strong thunderstorm will impact portions of west central Box
Elder County through 415 PM MDT...

At 328 PM MDT, Doppler radar was tracking a strong thunderstorm 13
miles northeast of Montello, moving east at 35 mph.

HAZARD...Wind gusts of 50 to 55 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could blow around unsecured objects. Minor
         damage to outdoor objects is possible.

Locations impacted include...
Lucin.

This includes Utah Route 30 between mile markers 1 and 32.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4165 11343 4134 11330 4123 11404 4144 11404
TIME...MOT...LOC 2128Z 249DEG 30KT 4136 11396

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...55 MPH

CRK

Special weather statement, Sep 12, 4:13 PM MDT, 1 hour 1 minute before

Special Weather Statement
National Weather Service Salt Lake City UT
413 PM MDT Sun Sep 12 2021

UTZ101-122300-
Great Salt Lake Desert and Mountains UT-
413 PM MDT Sun Sep 12 2021

...Strong thunderstorms will impact portions of northwestern Box
Elder County through 500 PM MDT...

At 413 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 9 miles west of Juniper to 8 miles west of Park
Valley. Movement was east at 30 mph.

HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Park Valley, Curlew Junction, Locomotive Springs and Rosette.

This includes Utah Route 30 between mile markers 41 and 87.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4189 11273 4188 11272 4170 11293 4172 11364
      4200 11328 4199 11284
TIME...MOT...LOC 2213Z 268DEG 26KT 4204 11316 4178 11349

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH

CRK

Special weather statement, Sep 12, 5:14 PM MDT, 0 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 6:19 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Emery, Garfield, Wayne	3 hr
Sep 11, 6:30 PM MDT	Special Weather Statement	SLC	Juab	45 min
Sep 11, 7:16 PM MDT	Special Weather Statement	SLC	Juab	44 min
Sep 11, 7:24 PM MDT	Special Weather Statement	SLC		51 min
Sep 11, 8:15 PM MDT	Flash Flood Warning Considerable damage threat	SLC	Garfield, Wayne	3 hr
Sep 11, 8:22 PM MDT	Special Weather Statement	SLC	Sanpete	38 min
Sep 11, 9:06 PM MDT	Special Weather Statement	SLC	Sanpete	39 min
Sep 12, 3:29 PM MDT	Special Weather Statement	SLC	Box Elder	46 min
Sep 12, 3:37 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder	23 min
Sep 12, 3:54 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder	51 min
Sep 12, 4:13 PM MDT	Special Weather Statement	SLC	Box Elder	47 min
Sep 12, 4:31 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder	44 min
Sep 12, 4:42 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder	24 min
Sep 12, 5:08 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder	20 min
Sep 12, 5:54 PM MDT	Severe Thunderstorm Warning	SLC	Box Elder	51 min

Nearby

Special Weather Statements in Utah, 2021 Every special weather statement 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.