Alert archive / Utah / Snow Squall Warnings in 2021

Snow Squall Warning 5, NWS Salt Lake City, UT

December 27, 20215 counties in Utah

NWS Salt Lake City, UT issued this snow squall warning at Dec 27, 2021, 4:01 PM MST for 5 counties in Utah. It was in force for 29 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
Dec 27, 2021, 4:01 PM MST (23:01 UTC)
Expired
Dec 27, 2021, 4:30 PM MST
In force
29 min
Issued by
NWS Salt Lake City, UT
Area
Storm-based polygon

Counties Box Elder County, UT, Cache County, UT, Davis County, UT, Morgan County, UT, Weber County, UT

The radar

The Salt Lake City radar (KMTX), 38 km from the middle of the area, began a volume at 23:03 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
Dec 27, 4:15 PM MSTNON-TSTM WND GST 65Hooper, UTFREMONT ISLAND - MILLER HILL - 4700 FT

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, 11.0 hours before the alert went out and 69 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 12:00Z on 2021-12-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Salt Lake City I, UT at 12:00Z on 2021-12-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 271 square meters per square second.1939587897117136156Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1580 m above ground
0-6 km bulk shear
84 kt
0-1 km storm-relative helicity
271 m²/s²
0-3 km storm-relative helicity
293 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

039 
WWUS55 KSLC 272301
SQWSLC

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service Salt Lake City UT
401 PM MST Mon Dec 27 2021

UTC003-005-011-029-057-272330-
/O.NEW.KSLC.SQ.W.0005.211227T2301Z-211227T2330Z/
Weber UT-Cache UT-Box Elder UT-Davis UT-Morgan UT-
401 PM MST Mon Dec 27 2021

The National Weather Service in Salt Lake City has issued a

* Snow Squall Warning for...
  Weber County in northern Utah...
  Southwestern Cache County in northern Utah...
  Southeastern Box Elder County in northern Utah...
  Northern Davis County in northern Utah...
  West central Morgan County in northern Utah...

* Until 430 PM MST

* At 400 PM MST, a dangerous snow squall was located along a line
  extending from near Brigham City to 15 miles north of Great Salt
  Lake South of the Causeway, moving east at 55 mph.

  HAZARD...Extremely poor visibility in snow and blowing snow. Wind 
           gusts greater than 40 mph. 

  SOURCE...Radar indicated. 

  IMPACT...Rapid snow accumulation on area roadways 
           resulting in dangerous travel. 

* This includes the following highways...
   Interstate 15 between mile markers 334 and 369.
   Interstate 84 between mile markers 82 and 98.

Locations impacted include...
Ogden, Layton, Brigham City, Hill Air Force Base, Roy, Clearfield,
Syracuse, Clinton, North Ogden, South Ogden, Washington Terrace,
Riverdale, Hooper, South Weber, Perry, Wellsville, Willard,
Marriott-Slaterville, Uintah and Mantua.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Consider avoiding or delaying travel until the snow squall passes
your location. If you must travel, use extra caution and allow extra
time. Rapid changes in visibility and slick road conditions may lead
to accidents.

Reduce your speed and turn on headlights! During snow squalls, the
visibility may suddenly drop to near zero in whiteout conditions.

&&

LAT...LON 4159 11177 4159 11216 4108 11273 4110 11171
TIME...MOT...LOC 2300Z 255DEG 48KT 4156 11203 4122 11248 

$$

MPS
1 follow-up statement
769 
WWUS55 KSLC 272319
SQWSLC

Snow Squall Warning
National Weather Service Salt Lake City UT
419 PM MST Mon Dec 27 2021

UTC003-005-011-029-057-272330-
/O.CON.KSLC.SQ.W.0005.000000T0000Z-211227T2330Z/
Weber UT-Cache UT-Box Elder UT-Davis UT-Morgan UT-
419 PM MST Mon Dec 27 2021

...A SNOW SQUALL WARNING REMAINS IN EFFECT UNTIL 430 PM MST FOR
WEBER...SOUTHWESTERN CACHE...SOUTHEASTERN BOX ELDER...NORTHERN DAVIS
AND WEST CENTRAL MORGAN COUNTIES...

At 418 PM MST, a dangerous snow squall was located along a line
extending from Mantua to 8 miles northeast of Great Salt Lake South
of the Causeway, moving east at 55 mph.

HAZARD...Extremely poor visibility in snow. 

SOURCE...Radar indicated. 

IMPACT...Rapid snow accumulation on area roadways resulting in 
         dangerous travel.  

This includes the following highways...
 Interstate 15 between mile markers 334 and 369.
 Interstate 84 between mile markers 82 and 98.

Locations impacted include...
Ogden, Layton, Brigham City, Hill Air Force Base, Roy, Clearfield,
Syracuse, Clinton, North Ogden, South Ogden, Washington Terrace,
Riverdale, Hooper, South Weber, Perry, Wellsville, Willard,
Marriott-Slaterville, Uintah and Mantua.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Consider avoiding or delaying travel until the snow squall passes
your location. If you must travel, use extra caution and allow extra
time. Rapid changes in visibility and slick road conditions may lead
to accidents.

Reduce your speed and turn on headlights! During snow squalls, the
visibility may suddenly drop to near zero in whiteout conditions.

&&

LAT...LON 4159 11177 4159 11216 4108 11273 4110 11171
TIME...MOT...LOC 2318Z 258DEG 46KT 4151 11191 4111 11232 

$$

MPS

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 27, 4:02 AM MSTWinter Storm WarningSLCBox Elder, Cache, Davis, Duchesne, Iron, Juab and 9 more31 hr
Dec 27, 4:27 PM MSTSnow Squall WarningSLCBox Elder, Davis, Morgan, Tooele, Weber48 min
Dec 27, 4:31 PM MSTSnow Squall WarningSLCDavis, Tooele44 min
Dec 27, 4:51 PM MSTSnow Squall WarningSLCDavis, Morgan, Salt Lake, Tooele54 min

Nearby

Snow Squall Warnings in Utah, 2021Every snow squall 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.